Device for electromagnetic logging of borehole

专利摘要:

公开号:SU1223849A3
申请号:SU813343903
申请日:1981-10-14
公开日:1986-04-07
发明作者:Тораваль Ивон
申请人:Шлюмбергер Оверсиз С.А. (Фирма)；
IPC主号:

专利说明:

the genus is made in the form of a plane parallel to the surface of the insulator; the invention relates to the exploration of subterranean formations using electromagnetic waves, and more specifically to devices for electromagnetic logging of a borehole.
There are known methods of exploration of subterranean formations intersected by a borehole, according to which a probe is moved along the wellbore and the given physical characteristics of the surrounding formation are determined as a function of the depth of the probe during logging (diagraphy), due to which information can be obtained that is necessary; or industrial development of minerals from underground formations of this well,
During the measurements, electromagnetic waves are used, for example, measurements of the specific electrical conductivity of formations crossed by the borehole are carried out using electromagnetic induction.
A device for logging using electromagnetic induction is known, in which a radiating coil mounted on a probe is driven from a generator with a frequency of about 20 kHz to induce currents into a geological formation surrounding a well. The magnitude of these currents depends on the electrical conductivity of the formation in which they occur. Currents circulate along ring lines centered on the axis of the borehole and cause the electromotive force to appear in one or several receiving coils installed on the probe at certain distances from the radiating coil. Analyzing the parameters of the output signal allows information on the electrical conductivity of formations crossed by these fl currents.
Measurement of electrical conductivity is one of the main methods of exploration of geological formations crossed by a squatting station along an elongated elactrode along a curvilinear path.
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zhina. Their complement is the electrical resistivity measurement methods based on the use of devices with electrodes. They are especially needed when filling the borehole of an exploration well with a solution designed to stabilize its walls, weakly - 1CIM electricity and not allowing the use of devices with electrodes 21.
Devices are known for measuring certain characteristics of the environments surrounding a borehole, in which the propagation of electromagnetic energy is used, in these environments, at frequencies significantly higher than the frequency used in performing induction logging. These devices use radio frequencies that range from a low frequency on the order of 1 MHz to a frequency on the order of GHz (III),
It is known that the characteristic parameters of the propagation of an electromagnetic wave in a medium such as geological formations also depend on the electrical conductivity of these formations and their dielectric constant.
The attenuation of an electromagnetic wave propagating at a distance in an environment that scatters electromagnetic energy Guy varies according to the expression
-JKP
(one)
where 6 is the exponent symbol
j is the operator of complex numbers; D is the distance traveled by the energy
K - wave number - constant distribution, determined by the formula
K - aijUot6 fjCcii)
(2;
In this equation:
UJ is the circular frequency for the considered frequency (o) 2 frf),
(U is the magnetic permeability of the medium under consideration,
6 - specific conductivity of the medium studied for conductivity,
 - dielectric constant
or the dielectric constant of this medium.
If we consider a non-conducting medium in which G is equal to O, then from equation (2) it follows that the constant K. is a real number. Then the exponential function index in expression (1) is an imaginary member which corresponds only to a phase shift in expression of the attenuation of transmitted signals. In other words, the propagation of electromagnetic waves in such a mode occurs without a total attenuation of energy when there is only a geometric attenuation in amplitude.
If the electrical conductivity increases (for example, a conductive drilling mud), then a moment comes when the term becomes much larger than the term joj. From formula (2) it can be seen that the term K becomes imaginary. In expression (1), the exponent becomes a member having a constituent and a valid constituent, essentially equal to each other.
When the propagation constant K continues to increase with electrical conductivity, the component of damping energy actually goes exponentially together with K. From the analysis it follows that in the first approximation the phase shift increases with the dielectric one. permeability, whereas amplitude attenuation increases with electrical conductivity.
In order to measure the characteristic parameters of the propagation of an electromagnetic wave transmitted at a radio frequency into a subterranean formation from a transmitter, usually at least two receivers, longitudinally spaced apart from each other, are used. The distance from the transmitter to the closest receiver in the direction of the borehole is determined by the transverse depth of the formation, the conductivity of which is measured. The distance between the receivers is determined by the thickness of the formation used to measure the propagation characteristics of the radiated wave. These characteristics are
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the relative attenuation of signals captured by the receiver closest and furthest to the transmitter, and the phase shift between the signals received by such a pair of receivers. The effect of formation electrical conductivity on decay and phase shift becomes decisive as the frequency of exploration decreases. And vice versa,
0 as the frequency increases in the ultra-high frequency region, it becomes decisive for the dielectric constant or dielectric constant of the formation’s intersected zone over
5 compared with electrical conductivity.
To measure the characteristic parameters of the formation, namely the electrical conductivity and dielectric constant or dielectric constant, two measurements of the propagation of electromagnetic waves are carried out for each of the zones of the formation being studied, for example, relative attenuation measurement and relative phase measurement.
A device operating in the ultra-high frequency (microwave) region is known for determining the propagation characteristics of electromagnetic waves in the medium immediately surrounding the wall of the well crossing the subsurface formations. Such a device comprises a probe equipped with a bow of a poppy intended to be pressed against the wall of a borehole in the barrel along which it is moved. The shoe has a transmitting antenna and several receiving antennas of the type of volume resonators. At a working frequency of 1.1 GHz, the attenuation and phase shift of the waves captured by receiving antennas are measured in order to find the value of the dielectric constant zone of a small
5. Thickness around the wellbore directly behind the mud (or mudcake) layer. At such high frequencies, the magnitude of the dielectric constant medium has a decisive effect on the measurements of attenuation and phase shift to the detriment of electrical conductivity, the effect of which on the measurements weakens as the frequency increases. Combination
5 measurements of attenuation and phase shift makes it possible to completely eliminate the influence of the latter factor on the definition of the dielectric constant
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or dielectric constant of the test medium 14J,
However, the use of ultra-high frequencies limits the depth of research with
Closest to the present invention is a device for electromagnetic logging of a borehole, which contains a probe for moving in a borehole, electrodes connecting to an electric circuit placed on this probe to effect the conversion between electrical signals in the probe and electromagnetic energy signals propagating in the environment 5 .
The measurements of the attenuation and relative phase of the waves propagating through the subterranean formations are performed differently for a given distance between the zone under study and the axis of the trunk.
If it is necessary to reach greater depths of exploration, it is necessary to distribute, the electrodes are at a distance, which makes their installation on a bashmak difficult to implement. Then they are installed directly on the body of the logging probe.
If the distance traveled by the waves between the electrodes increases with the depth of exploration and zatu: the attenuation of an electromagnetic wave in its propagation medium is an increasing function of frequency, lower operating frequencies are used, for example, 20-30 MHz.
In order to obtain measurements of the phase shift caused by the propagation in the zone of the underground formation located at a certain distance from the well, electrodes are used that are located from the transmitter at a distance greater than the distance that separates them from the electrodes intended for measuring the attenuation of the wave in the same zone. .
Converters used for electrical logging, namely, emitters and receivers, must meet certain conditions. In particular, they must be adapted to transfer energy to highly dissipative zones, to areas where energy transfer is accompanied by heavy losses. During transmission, such converters must transfer large amounts of energy to the environment, during
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On the contrary, they should often pick up low levels of signals. In addition, transducers must have special properties on the direction. With electromagnetic logging, the waves propagate in a) direction of the subterranean formations, rather than longitudinal in the wellbore. Therefore, it is important to ensure that the converters used in logging have pronounced — properties — directivity.
The use of coils to some extent makes it possible to eliminate the disadvantages associated with antennas formed by capacitor plates. In particular, coils may function weakly in search of drilling mud. However, it has been observed that this improvement has its limits and that the level of signals arriving at receivers after propagation through underground formations is often extremely low. To eliminate the distortions of signals captured by receivers, it becomes necessary to use extremely sensitive electronic circuits, which makes the implementation of the device more difficult and its operation more difficult. This is especially true for devices that work together with a pair of coils relatively distant from the transmitter, where there are devices operating to measure the phase shift corresponding to the formation being studied.
In addition, it should be taken into account that the attenuation of an electromagnetic wave in its propagation medium increases sharply with the electrical conductivity of this medium. Therefore, when using known devices with a drop in the resistivity of the drilling fluid less than 0, 1 Ohm per meter of attenuation of waves in the drilling fluid, during transmission and reception, it becomes such that it is impossible to obtain from the receivers the processing indications of wave propagation through the formations considered.
The power emitted by the rolls can be increased by increasing their diameter, the advantage of which is also the reduction in the thickness of the drilling fluid intersected by the electromagnetic energy coming out of these coils and the corresponding attenuation. However, the increase in. External dia30
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The meter of device is limited by the size of the wells in which it is to be used, and overall considerations.
In the field of aviation and space communications, it is known to use antennas formed by a dielectric plate, on the surface of which an elongated wire and element are located, while its surface is metallized to form a second conductive element or plane of mass. In such two-plate antennas, methods of manufacturing printed circuit boards are used. Their advantage is the relative simplicity of matching with the form of aviation or space devices with a relatively limited volume. They have shown themselves well for all-round transmission in air or in vacuum, where the propagation of electromagnetic waves occurs almost without loss. The return of such antennas increases in the square of the frequency used and is quite acceptable for use in communications at frequencies of up to several hundred megahertz. But it is not as large as that of traditional aviation antennas, whose dimensions increase as a function of the propagation wavelength of radiation that they must transmit in air. or in a vacuum. However, in view of the small attenuation introduced by the propagation medium, the degradation of the performance of two-spot antennas is compensated by their advantages, especially in terms of dimensions.
The aim of the invention is to improve the accuracy of measurement of the characteristics of the propagation of electromagnetic waves in the environment surrounding the borehole, crossing geological formations.
The goal is achieved by the fact that in a device for electromagnetic logging of a borehole, which contains a probe for moving in a borehole, electrodes connected to an electrical circuit placed in this probe to effect the conversion of electrical signals generated in the probe, and signals of electromagnetic energy propagating in the above mentioned probe has at least one antenna containing an elongated electrode and an electrode located opposite and at a given distance from the elongation nnogo electrode throughout the useful length of the latter, when
In this case, the opposite parts of the elongated electrode and the electrode are separated by an insulator and are electrically connected to each other at one of the ends of the length of the elongated electrode,
moreover, the end of the elongated electrode is electrically connected to the electrode by means of an inductance coil, the elongated electrode is placed along a curvilinear path parallel to a predetermined surface of the insulator, the electrode is parallel to this surface, and the elongated electrode is located on the outer side of the probe.
In this case, the electrical connection between the electrodes is made in the form of a short-circuited jumper, and the useful length of the elongated electrode, measured from its short-circuited ends, is chosen as a function of the wavelength
electromagnetic propagation
energy of a given frequency in the isolator.
In addition, the antenna is connected by an electrical cable for transmitting electromagnetic energy to
given frequency between the antenna and the electrical circuit in the probe, while the sheath of the coaxial cable is connected to the electrode, and the electrical conductor is connected to the elongated electrode
at the location required to match the impedance of the antenna with the impedance
coaxial cable. I
The electrode is made in the form of a plane parallel to the surface of the insulator, on which an elongated electrode is placed along a curvilinear path. Improving the capabilities of electromagnetic logging devices is achieved by increasing the radiation power,
created by these devices, within the size of the probes, acting under operating conditions in boreholes.
The device contains as
A radiation converter is a present antenna, which can optionally be matched as a function of the frequency of the transmitted radiation. For this, the electrical connection between the two components is short-circuited, and the useful length of the first element is adjusted as a function of the propagation wavelength of said
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electromagnetic energy in a non-conducting medium.
These antennas can be effectively adapted for use in logging devices for transmitting or receiving radiation in the vicinity of a borehole when there are operating characteristics in the plane of recoil that are much higher than the characteristics of radiating systems of known devices.
Such an antenna can be implemented using the production technology of so-called double-plate lines, according to which the first elongated conductive element — the electrode — is applied by printing onto the first surface of an insulating material plate, while the other surface is metallized to form a second conductive element or mass plane. This technology is used to produce antennas designed for the non-directional transmission of electromagnetic radiation in a non-absorbing medium such as air or vacuum, i.e. in which the propagation of electromagnetic waves occurs with almost no losses, which is essential for the transmission of information
Such antennas with good operational characteristics can operate in highly absorbing media such as those that change when logging boreholes, 1, l to measure distortions of transmitted electromagnetic signals. In addition, in environments surrounding the borehole, in particular, in drilling fluid-type fluids, such antennas operate with a very good return on the frequent order of several tens of megahertz used in electromagnetic logging equipment in deep prospecting The recoil obtained significantly exceeds the recoil of the same antennas in air or in vacuum at the same frequencies. This effect is extremely beneficial with relative sizes of propagation of radiation in such media. Indeed, the greater the power radiated When transmitted, and the more power at the receiver input signal after propagation of the radiated medium ,, in the easier and more precise can be stvunntsie corresponding measurements of attenuation and / or the Optional .zovogo shift.
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Antennas of the specified type can be adapted to give them the appropriate directivity characteristics suitable for logging wells in wells. At the same time, adjusting the mechanical length of an antenna mounted, for example, on the body of a logging device, causes a phase shift in the current along the antenna, which contributes to the propagation of radiation into the environment in the transverse direction relative to the body between the transmitting and receiving antennas.
The use of antennas of this type in well logging equipment has a significant effect.
The non-conductive probe medium is a dielectric plate. According to another variant of the Q design adapted to operate in a device at low frequencies, the non-conductive 1st probe material is a magnetic material with a high magnetic permeability.
In a preferred embodiment, the impedance of each antenna is matched with the coaxial link line impedance by adjusting the position of the connection point of the coaxial line and connection along the length of the first conductive element.
In one of the constructive forms, the antenna is mounted on the body of the device. It is preferable to place the first conductive element around this housing to reduce its length parallel to the longitudinal size of the latter. The second element, the forming element and the cylindrical element of mass, is located inside the first element.
Then the second element can play the role of a screen relative to the first element against the effects of interference from the CIA deposit inside the probe, for example, from the current supplying the transmitter generator. In particular, the second element can be extended beyond the antenna to form a tube of the probe screen from the inside Ning exe device. To improve the protection of the antenna design, various options are provided that extremely reduce or completely eliminate the propagation of electromagnetic energy with a transverse mode (TEM type wave) from the transmitter to the receivers, which also provide the best leveling of the internal space of the device.
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When the second antenna element forms a cylindrical mass element inside the first element, the latter can be extended on one and the other sides of the antenna to get direct electrical contact with the outside of the probe. Preferably, probe formation by a tubular steel structure, part of which is used to form a second antenna element covered with a dielectric material serving as a support for the first or radiating antenna element.
Thus, in the proposed device, the probe body is a conductor. Such a design can be used in all areas of the frequency of use of the device, including at the lowest frequencies. This makes it possible to combine devices using electromagnetic radiation with devices that use other types of physical phenomena. One of the designs provides for a metal electrode-conductor of current across the formation being studied for measuring the resistivity together with an antenna of the specified type, the second conductive element of which is electrically connected to the electrode housing.
It is possible to envisage an increase in the output of the antennas used in the proposed device, as compared with the traditional coils used in the well logging equipment. The minimum recording radiation power of steel is an order of magnitude larger than previously obtained. This improvement greatly expands the capabilities of the proposed devices and their range of application, especially when antennas are used both as receivers and as transmitters, while the efficiency of the radiating system is more a few thousand hours.
Devices equipped with antennas of the specified type enable exploration of environments surrounding the wellbore, in which the resistivity of the drilling fluid is significantly less than what was previously considered minimal for accurate operation of devices with electromagnetic propagation. Offered devices
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have reduced both external and internal dimensions
The considered antennas are especially well combined with the installation on the housing of deep prospecting devices, which should act at frequencies of several tens of megahertz, as well as devices on coils.
However, it has been found that these antennas can be used with electromagnetic logging tools in a relatively low frequency range, such as below 10 MHz, which is particularly preferable when using material with high magnetic permeability between two conductive antenna elements, and also can be used at higher frequencies. range, e.g. more than 200 MHz. In particular, in the latter case, the antennas mounted on the shoes are relatively simple.
FIG. 1 shows schematically a known device for electromagnetic logging, FIG. 2 shows an electrical connection circuit of a known antenna, FIG. 3 shows a two-plate type antenna, FIGS. 4 and 5 shows a design and connection diagram of a two-plate antenna, FIG. 6 is an antenna for a probe body; FIG. 7 is another form of antenna design for a probe body; FIG. 8 is an antenna mounting diagram for an electromagnetic logging tool; FIG. 9 shows a variant of the antenna structure for the probe body of FIG. 10; a logging probe equipped with antennas on the body; FIG. 11 shows a variant of the probe design; in fig. 12 is the same section along the diametrical longitudinal plane; FIGS. 13 and 14 show the connection diagrams of the two-plate antennas of FIG. 15; two-plate antenna in the form of a disk; FIG. 16 shows a logging shoe containing two plate antennas, FIG. 17, a second embodiment of the shoe design; FIG. 18 - the third version 0 of the shoe design; Fig, 19 is a schematic depiction of the design of the device in combination with electrodes and antennas.
A borehole 1 (Fig. 1), bounded by the borehole wall 2, passes through geological formations 3 from the soil surface 4 in the vertical direction. Well filled
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drilling mud 5, and the density of the drilling fluid is determined and adjusted so that the hydrostatic pressure created by the drilling fluid on the wall 2 of the borehole 1 balances the internal pressure of the passed formation and maintains the integrity of the wall 2, the device is suspended in borehole 1 6 for electromagnetic logging (diagrams); It is | mounted on cable 7, which serves for its mechanical suspension, during movement in the borehole 1 and for electrical communication of the device
6 with a ground station of a logging station 8. On its way to this station, cable 7 passes through block balance 9, the angular displacement of which makes it possible to track and: change the depth of the device, and also allows controlling the recording medium, magnetic or photographic, for example a registration device 10 for taking measurements or diagrams of data transmitted from device 6 via cable 7, in-function Ji device 6.
The device 6 comprises an elongated probe body 11 or a cartridge suspended by the upper edge 12 on the cable
7 and containing outer shell
13, designed to isolate the working parts of the device from the borehole 1. A radiator is installed adjacent to the inner edge of the housing 1i.
14, an antenna image for transmitting electromagnetic energy at radio frequencies in the immediate vicinity of the borehole 1 and adjacent 1x formations 3 "A radiator 14 on the housing 1f has a first pair of receiving antennas 15 and 16 vertically spaced
specified distance. Distance between /
The radiator 14 and the midpoint L 2 interval separating the receiving antenna 15 and 16 are equal to Dfi.
Above this pair of antennas on case 11, another pair of receiving antennas 17 and 18 are installed, also spaced longitudinally. The middle Li of the interval between these antennas is located at a distance Df from the radiator 14,. exceeding the distance Ou.
The emitter 14 is designed to emit an electromagnetic wave at a dihedral angle of 360 around the axis of the probe body 11 with It receives power
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from the generator 19 located inside the shell 13 using coaxial cable 20. The generator 19 controls the generator 21, designed to operate at a slightly higher or lower frequency (shifted by several tens of kilohertz) o
Receiving antennas 15 and 16 are designed to detect electromagnetic radiation reaching the receivers after propagating through formations 3 in the dihedral angle 360 around the axis of the borehole 1. They are connected to amplitude comparator 22, which receives the frequency from the upstream generator 21 at its input 23,
Receiving antennas 17 and 18 are connected to the inputs of the phase detector 24, the input 25 of which receives the frequency from the generator 21 output
Receiving antennas 15 and 16 are connected to amplitude comparator 22 via coaxial cables 26 and 27, respectively. Receiving antennas 17 and 18 are connected to phase detector 25 by coaxial cables 28 and 29, respectively. The amplitude comparator 22 and the phase detector 24 contains each; a mixer of signals from the generator 21 and signals perceived by receiving antennas 15, 16 and 17, 18, respectively, with the purpose: to receive signals from a relative low frequency (several tens of kilohertz) to determine, on the one hand, , the differences in the signal amplitudes of the signals received by the receiving antennas 15 and 16, and, on the other hand,
the phase differences of the signals are received by the receiving antennas 17 and 18. Two corresponding thin types of information appear at the outputs 30 and 31 of the amplitude comparator 22 and the phase detector. 24, respectively, and transmitted to the surface via cable 7 to processing device 32, intended for supplying logging signals to the recording device 10, representing, for example, the dielectric constant and / or electrical conductivity of the formations under study by: and propagating the waves emitted radiator 14 ,. Cable 7
provides the energy supply to the Torah gene-Yra 19 and 21, as well as to the amplitude comparator 22 and phase detector 24 located in the probe 11.
However, the use of such devices poses certain difficulties due to the insufficient electromagnetic radiation power that they can provide in the formations under study. However, if the attenuation of electromagnetic waves propagating in a certain medium increases with the conductivity of this medium, it is impossible to use such devices in drilling muds with a specific resistance of less than 0.1 ohm per meter, which significantly narrows their field of application.
The emitter 14 and receiving antennas 15 and 16 of such devices usually consist of coils with a small number of turns, for example two, mounted on an insulating sleeve made, for example, from ceramics. There are known how to attempt to increase the radiation power generated by such coils. However, these forces hit the dimensional limits of the drilling devices and the electrical powers that can be created in devices hung at the end of a cable with a length of several thousand hours.
The antenna 33 of the two plate type (Fig. 3) is formed by a combination of two metal elements applied on both sides of the dielectric using the methods used in the manufacture of printed circuits. The flat dielectric plate 34 contains on one of its surfaces 35 a conductive copper plate 36, which in this case has a curvilinear shape and is made in the form of a shoulder on a dielectric plate 34. Such a dielectric can be, for example, high-temperature ceramics. Opposite to the surface 35 of the dielectric plate 34, the surface 37 is completely covered with a metal coating, i.e. a plate 38, made, for example, from copper, aluminum or Invar. The edge 39 of the metal plate 36 is electrically connected to the metal coating 38 by means of a short-circuited connection 40 through the dielectric plate 34. A coaxial cable 41 passes from the bottom surface 37 to the antenna 33. The sheath of this cable 41 is electrically connected to the plate 38, while its core after passing through the dielectric is soldered to
plate 36 at point 42 located at a predetermined distance from edge 39. The curvilinear length of plate 36 on the dielectric plate 34 between one edge 39 and another 43 is electrically not connected, in this case, equal to a quarter of the propagation wavelength of the operating frequency of the antenna.
Plate 38 is usually called the mass plane, and plate 36 is considered as the radiating element itself.
In the general case, plates containing the first and second metal elements of parallel plates 36 and 38 are separated by a non-conductive medium formed, for example, by a solid dielectric plate 34. These elements are electrically connected to each other at the edge, the length of the first element being defined in functions of the wavelength with which electromagnetic signals propagate in the dielectric separating the conductive elements at a given frequency. It is known that when the length of the antenna transmitting electromagnetic radiation is equal to a quarter of ins this radiation wave or a multiple of the latter, the input impedance is deystvitelnymo In this case, achieved optimal radiation of this antenna.
In an antenna of this type, the conductive elements are separated by a dielectric and are located opposite each other, but for operation it is not necessary that the second conductive element corresponding to FIG. 3 plate 38, stretched across the surface.
It is possible to realize antennas in which the second conductor is also an elongated element located parallel to the path of the first conductor and opposite the latter. Such an arrangement in which the second element extends in two directions along a plane or surface of the mass gives a definite advantage.
When the operating frequency of the antenna is relatively low, for example, on the order of several tens of megahertz, a quarter of the corresponding wavelength in the air is a relatively large amount compared with the size of the devices for carrying out ka17.
Rotazha drilled wells. At a frequency of 25 MHz, a quarter of the propagation wavelength in air is approximately 3 m. If the antenna is not installed in air, but in a dielectric material (Fig. 3), the wavelength emitted in this dielectric is less than the wavelength of radiation in air in the strength of the greater value of the ds-electric constant of the material. This is clear from relation (2), which determines the constant distribution of Ko. When the conductivity O of the medium in which the antenna is placed is zero, we can write the equation
K u). Knowing that at zero conductivity the propagation constant is equal to
K.217l.
where L is the wavelength, you can write
A-gt and} .y / uo t
If the dielectric constant of the dielectric material on which the first element is applied is greater than 1, i.e. the dielectric constant of air or vacuum, the radiation propagation wavelength in this medium decreases as a function of the square root of this dielectric constant. For a dielectric medium with a permeability of 4, the corresponding wavelength will be on the order of half the wavelength of radiation of the same frequency in air. It follows that the length of the antenna matched for a quarter or half of the wavelength can be divided into two when the antenna is placed in a dielectric. Then, at a frequency of .. 25 MHz, the length of the antenna, necessary to obtain a good return in the dielectric, is 1.5 m. Various measures are provided for implementing such antennas in the minimum dimensions of the device for conducting borehole logging.
When the frequency of the emitted signal increases, the corresponding wavelength decreases and the antenna can be given a length equal to half the radiation wavelength in the dielectric. In this case, the two edges of the first element, plate 36, are short-circuited.
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with the plane of mass, i.e. The plates 38. Of course, as the frequencies of the emitted electromagnet magnet waves increase, it is possible to increase the length of the antenna 5 with respect to the wavelength in the dielectric for given dimensions, which in any case is a factor in the increase in recoil.
Test antennas reviewed
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type showed that on the one hand.
The antennas can be satisfactorily used to exchange radiation energy with a highly absorbing medium to radiate the propagation of electromagnetic radiation in these environments, on the other hand, with their HELP, significant returns can be obtained both during transmission and during reception of electromagnetic propagation measurements in boreholes compared to traditional coils used by this area. In the first case, it should be noted that the properties of two-plate lines
discovered and used to transmit electromagnetic signals in environments where attenuation during propagation of signals is extremely weak. Experiments have shown that antennas of the type described can work satisfactorily in highly absorbing media, and that in drilling logging tools operating in drilling mud, the effectiveness of antennas exceeds the efficiency they have in air or vacuum, all other things being equal.
In the air, these antennas have recoil, which increases in the square
transmitted frequency. When using antennas for space or aeronautical communications, they operate at frequencies of several hundred megahertz with recoil, which, although less than recoil from classical aviation antennas, is perfectly acceptable for communications during transmission in an absorbing medium. Thus, these antennas can be used with excellent performance in conditions of boreholes at frequencies much lower than the existing frequencies of their use in air or vacuum. These are frequencies of several tens of megahertz corresponding to the frequencies used in electromagnetic propagation devices for deep prospecting.
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An explanation of such a decision can be obtained if we consider the approximate ratio
(-1y
(four)
where r j t
L antenna radiation resistance
the mechanical length or effective height of the antenna, the wavelength of radiation propagation in the medium in which the antenna is located. The energy of the radiation received or emitted by the antenna is by. its nature is active. The radiation resistance g is the magnitude of the fictitious resistance that will create thermal energy dissipation equivalent to the radiated energy. Then the greater the radiation resistance of the antenna, the greater the power that it can transmit. Recoil 1 antenna can be characterized by taking into account, on the one hand, the resistance:} of radiation corresponding to the useful energy transfer, and, on the other hand, the loss resistance I - Rr - / {Rf «-Rp)
If paccMoi peTb is the radiation resistance of the antenna from air or vacuum, then
“--- (Ы
(five)
Where
Separate according to high water.
The constant water i is about 80 ,. Consequently, the radiation resistance of P-d in water is approximately VO larger than in air. From this it follows that with a certain return of the antenna T-in the air, the corresponding return of the same antenna in the water is much larger and approaches 1 in measurement, when the loss resistance is ftr, which has not changed, may be assumed to be negligible compared to the radiation resistance of the antenna in water.
Relation (5) is valid for a non-conducting medium. In practice, consideration of relation (2), which determines the constant distribution, allows us to come to the conclusion that if
radiation wavelength in air.
The wavelength of the radiation in water is determined by (5): L in
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conductivity surrounding antenna
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Since the wavelength is not zero, the propagation wavelength tends to decrease further with respect to its value in a non-conducting medium.
This makes it possible to effectively adapt antennas of the type in question to the specific conditions of their use in logging equipment. In addition, it is possible to satisfy the overall limitations of such devices, along with giving a certain directionality when transmitting energy in the transverse direction relative to the direction of the borehole. In practice, it is possible to place a plate of insulating material in such a way that the one of its surfaces, on which the first conductive element is applied, is on the surface of the device, be it a case or a shoe. If necessary, this conductive element can be deposited on the surface of the probe or shoe body in order to give the antenna the necessary electrical length while maintaining its mechanical length in dimensions compatible with the dimensions of the device. Moreover, the mechanical length of the antenna can be adjusted as a function of the directional characteristics that the device should have. depends on the phase shift of currents per unit of mechanical length along the antenna. It is desirable that the antenna length be sufficient to obtain such a phase shift of the currents, which contributes to the antenna in certain directions to the detriment of others, which is usually achieved by providing an antenna length of the order of the wavelength of the radiation in external dl
antenna environment.
In terms of a significant improvement in antenna performance in comparison with coils traditionally used in measurements of the type in question, one can say the following.
It has been established that the recoil of traditional coils is extremely small. A radiation converter of such coils (Fig. 2), such as an emitter 14, formed by a coil 44, can be represented by a circuit consisting of an inductance 45 connected in series with a resistor 46 connected to the output of a coaxial cable 47,
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with generator 48, the impedance of such a coil 44 is largely reactive due to the significant inductance value of 4.5, while the coaxial line of communication — cable 47 — designed to power this coil is designed to transmit to the coil mainly active radiated energy . Incorrect impedance and i / v matching cause poor high-frequency energy from generator 48 to antenna coil 44. It is reflected in the creation of a standing wave system between generator 48 and antenna coil 44 through a coaxial communication line - cable 47, maintaining Absorbs a very significant part of the energy transmitted by this line. Under these conditions, the recoil in the transmission of energy between the generator 48 and the coil 44 does not exceed 10%. A similar phenomenon is observed in the coaxial lines of communication of the receiving antennas.
Only a small part of the energy reaching coil 44 (in the case of a radiator) is converted into radiation energy distributed outside device 6 (FIG. 1), and this energy corresponds to the radiation resistance, since there are significant losses caused by the existence of the Joule effect in the winding coils.
These ohmic losses are summed with the dielectric losses caused by capacitive coupling between the coil conductors and other parts of the device connected to ground. Therefore, the power radiated to the outside of the coil represents a fraction of a few percent of the power effectively reaching this coil. In sum, the power radiated by the system with the coil does not exceed about 1% of the power available at the output of the reijepaTopa power supply. Similar effects affect the recoil of the coils when used as receivers.
Compared to these coils, the proposed radiation converters are real-life antennas, the length of which can be matched as a function of the frequency of the radiation that they transmit when they are
This is a prerequisite for good performance at work. Therefore, the impedance of such antennas has a very small reactive component in
Unlike coils, this {{nyyy} result can be achieved by applying the proposed design with its dimensions compatible with the size of devices intended for use in boreholes.
The active cyiuHocTb impedance provides advantages not only in creating favorable resonant, conditions for the antenna to convert electrical energy into electromagnetic energy, but also in terms of recoil when transmitting electrical energy along a coaxial communication line connecting the antenna to an electronic circuit. This eliminates the signal losses inherent in the coils.
In addition, these antennas allow a very simple matching of the impedance of the antenna with the impedance of the coaxial cable connecting it to the electronic power supply or signal processing circuits
In the two-plate antenna of FIG. 4, the generator 49 is connected to the single end 50 of the coaxial communication line - cable 41, while at the other end the sheath 51 is connected to the plane of mass - the plate 38 perpendicular to it, the coaxial cable 52 is insulated from the plane of the mass - plate 38 and intersects dielectric plate 34 for joining at connection point 42. The plane of mass - the plate 38 forms an electrical screen between the plate 36, forming the sensitive part of the antenna-coil 44, and electronic circuits located behind the plane of the mass. The junction point 42 of the sheath 51 of the cable 41 is located at an oC distance from the edge 39 of the short
tabs of the antenna 33 selected to match the impedance using plate 36 as an autotransformer. Presented in FIG. 5, the circuit of such an antenna 33 contains between the edges 39 and 43 of the plate 36 a coil of inductance, the number of turns of which corresponds to the length of this plate, and a capacitance C equivalent to a capacitive coupling existing between the plate 36 and the mass plane, t, eo plate 38 " The plane of mass, t, e. plate 38 is connected to ground. The parallel LC circuit is a resonant circuit equivalent to an antenna. With a length of antenna 231
one-quarter of the wavelength emitted in the dielectric, the impedances of the circuit containing inductance L and capacitance C correspond to such a resonance condition which allows an optimum conversion of electrical energy into radiation energy “Connected in parallel L and C between the edges 39 and 43 of the antenna, the resistor R. is equivalent to the impedance of the loss due to the conductivity of the antenna and the power dissipation (radiation resistance), and this power is purely active. The intersection point 42 is an intermediate inductance point corresponding to the number of turns P I of this inductance between the mass plane and the plate 38 and the point 42, and IT.T is the total number of turns of the inductance L. The position of the point 42 is chosen such that nL / nt) xR is essentially equal to the impedance of the coaxial line of the cable 41. The inductance plays the role of an autotransformer. From here, the impedance brought to the input will be (ol / nt) xR If this impedance is equal to the impedance of the coaxial line used with the antenna, virtually all loss of reflection energy in the coaxial is eliminated, which contributes to a good return of the antenna.
Potential increase in power distributed to the environment. The device for borehole logging, which results from the use of two-plate type antennas, has very significant implications for the applications and implementation of such devices. Some technological features of two-plate antennas are implemented by their various variants.
For example, in a two-plate antenna on the probe body (Fig. 6), the first conductive element 53 is wound in a spiral shape with a regular pitch around a cylindrical sleeve 54 of a dielectric material, the inner surface of which is coated with a conductive coating 55, forming a second conductive element or mass element Conductive element 53 is a copper plate printed in the form of a print on the surface 56 of the sleeve 54 along a length equal to the scan of a quarter of the propagating wavelength 238492
the emission of radiation at the considered frequency in the material forming the sleeve 54. The step of winding the strip 53 is relatively compressed, and the longitudinal distance between the turns of the strip is significantly less than the width of the strip of the element 53.
The sleeve is made of ceramic or composite material based on
Q fiberglass and resin. Element 53 is embedded in it using the classic printing technology used in the preparation of printed circuits, for example by etching or electro-electrodissuing - day. The inner edge 57 of the first element 53 is electrically connected to a high-frequency power source: you are on a coaxial line 58, the core of which is connected to point 59
2Q on the inner surface of the spiral element 53 (i.e. its surface contacts the dielectric of the sleeve 54). The coaxial core is crossed by a dielectric perpendicular to the inner
25 of the surface of the dielectric sleeve 54, the coaxial shell is connected to the cylindrical coating 55.
This antenna is designed to be mounted coaxially with the body of the logging device shown in FIG. 1, in order to receive the radiation of the radiator 14 and the receiving antennas 15 and 16. As an example, it can be said that the antenna made for this purpose contains eight turns
5 metallic copper strips with a thickness of one tenth of a millimeter and a width of 5 mm (the size is determined in the axial direction), the pitch of the helix is 7.5 mm on the sleeve with the outer diameter
 8 centimeters.
The inner surface of the sleeve is coated with a metal layer 1 mm thick forming the plane of mass.
5 The insulating sleeve is made of poly-sulphone and has a thickness of 5 mm. For operation at a frequency of 25 MHz, the antenna tuned to a quarter of the propagation wavelength of this frequency in the electrical material of the sleeve 54 has a developed length of about 2 and a total length in the axial direction or. a mechanical length of 6 cm. Radiation measurements taken with such an antenna when operating in salt water gave values in the order of 90%, which is significantly more than it was with the previously used coils.
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/ | Antenna antenna tuning is 1v per quarter of the radiation wavelength in the dielectric, due to which the antenna resonance condition is maintained without any additional structures and especially without the need for individual matching circuits. Such circuits are needed with converters on coils to bring circuits with coils into a resonant state. The elimination of matching schemes is an advantage, since they are difficult to manufacture, they contribute to the leakage of energy to radiation and occupy considerable space in the device.
The radiating antenna is separated from the receiving antennas by sections of insulating tubes, with which they are connected by appropriate means, such as HF, connecting sleeves. In another embodiment, the antennas are arranged around an inner common insulating sleeve having a longitudinal support in the housing 11. In one embodiment, the shell of the probe body 13 is made at least partially in length by extending the antenna sleeve of the sleeve 54 type (Fig. 6) to the height of the housing, the same sleeve now serving as the support for the first and second conductive elements of various transmitting and receiving antennas.
In one implementation, the elements of the mass type of coating 55 forming the second element of each of the receiving antennas 14-16 (Fig. 1) are part of the same conductive sleeve extending along its entire height. This arrangement is of interest when the conductive sleeve thus obtained acts inside the device as a shield for transmitting and receiving antennas from interference signals circulating in conductors inside the device case. These are, for example, the supply current of generator 19, which generates power, which is taken into account in geological formations,
In this connection, electromagnetic propagation devices contain electronic signal processing circuits captured by receiving antennas 15-18 (Fig. 1), which must be due to the weak level of these signals in close proximity to the radiation receivers. Usually
these electronic circuits are located either in the upper part of the probe body 11, or in the pedal compartment arranged above the probe case with which it is fastened by cable 7, the Emitter 14 must be placed under the receiver in the lower part of the device 6 and its power generator 19 must be placed in proximity to it to limit the length of the power cable coaxial cable 20. The electrical conductors of the cable 7 running from the surface to power this generator must pass through the entire probe body close to the receiving antennas 15, 16, etc. With a low level of signals circulating in the receiver circuits, in response to radiation captured from the environment, it is necessary to protect the receiving circuits from the harmful effects of currents induced by the conductors of a high-power generator 1 9.
To eliminate interference, the installation of a power supply battery for a generator 19 intended to power the generator during measurement periods when the radiator transmits electromagnetic energy in the direction of helogic formations can be used, and the battery must be recharged from the surface during electromagnetic radiation detection work. the adverse environment in which the equipment must work; logging tools in bore and bbjx wells, and especially for very high temperatures. The inconvenience of the battery lies in its certain fragility, inadequate reserve of energy for long-term logging and its questionable reliability. Because of this, the power supply conductors in the cable must be surrounded by a screen made of a longitudinal metal tube passing through the probe from generator 19. In the case of devices on coils, where the radiated or received energy depends on the magnetic flux intersecting the coils, the shielding the tubes are degraded to the detriment of the surface available to the flow. Conversely, the operation of two-plate antennas is not affected by the presence of a tube, the diameter of which can be increased to accommodate electronic circuits and other operating elements.
devices. This makes it possible to reduce the device or improve the performance of the electronic signal processing circuitry inside the probe.
It is possible to envisage the use of cylindrical mass elements such as the coating element 55 (Fig 6) as a shield from interfering signals, circulated through the generator power cables and all other circuits necessary for operating the device, connecting them to each other with metal tubes to form a continuous metal a cylindrical shell c; A shielding tube formed by such a shell is connected to antenna sleeves placed at a small distance from the periphery of the shell of the probe body 11, and separates the central the inside of the device with
However, in some cases, it should be feared that the shielding metal envelope does not play in combination with the drilling fluid surrounding the probe body 11 and the separating insulating medium, a coaxial connection in which part of the electromagnetic energy emitted from the radiator will propagate. 14, in the transverse propagation mode, known as TEM type waves (transverse electromagnetic waves). When using electromagnetic logging devices, this propagation mode should be avoided, since the wave propagating between the transmitter and receiver along the coaxial created between the inner shell of the device and the drilling fluid has an amplitude significantly exceeding the amplitude of the signals to be captured, and can completely mask the useful signals. Therefore, it is so important to avoid the occurrence of this mode of propagation and to concentrate the largest part of the energy emanating from the radiator 14 on the walls of the wellbore and surrounding geological formations.
According to one design variant, it is provided to limit the transmission of the TEM wave by installing a conductive element wound around an antenna hub coaxial with the probe body not in a plane (Fig 6), but in a recess (Fig 7), where antenna 60 contains a dielectric
a sleeve 61, on the inner surface of which there is a cylindrical mass conductor 62 connected to a cylindrical shell (not shown) extending along the entire length of the device, combining all the mass conductors corresponding to other antennas. Metal tape 64 is wound around the mass cylinder 62 in recess 63 with electrical contact with this cylinder, located in a plane approximately perpendicular to the surface of mass cylinder 62 and spiraling around the cylinder at the height of the sleeve 61 corresponding to the length of the antenna. The outer edge 65 of the tape 64 reaches the outer surface 66 of the dielectric sleeve 61. The first antenna element is formed by a conductive metal tape 67 wound in a spiral in the thickness of the sleeve 61, forming turns arranged in the field and alternating with the turns of the tape 64, with the outer edge 68
extends to the outer surface 66 of the dielectric bushing 61, the Tape 67 is electrically connected to one of its edges 69 with a metallic coating, a conductor of mass 62, entering
inside the dielectric sleeve 61, the antenna thus obtained is connected to a coaxial cable 70, the end of which is perpendicular to the inner surface of the sleeve 61, the cable jacket is electrically connected to the mass cylinder 62, and the core is connected to the tape 67 at point 71 at a given distance from edge 69 along this winding to effect impedance matching,
mentioned earlier. Spiral tape 67 occupies a distance along sleeve 61 that corresponds to the unwrapped length of the required antenna,
This arrangement makes it possible to reduce the transmission of electromagnetic energy in a direction parallel to the axis of the probe body 11 (Fig. 1). In fact, the formation of waves propagating in the TEM mode within a coaxial connection is mainly caused by the existence of a distributed capacitance between turns of the tape 67 and a pillar of drilling fluid surrounding
device. The amount of this liquid depends on the effective surfaces of the facing plates. In the construction of FIG. 7, the recess surface for
The turns of the tape 67, which are opposite to the drilling mud column, are greatly reduced and only contribute to the NMHH-mapping of the waves propagating in the TEM mode.
For this, a metal sleeve 72 is placed inside the insulating shell 73 of the electromagnetic logging housing. (FIG. 8) in the extension of a cylindrical mass 74 of a two-plate type antenna 75 with field creation conductors 76 and 77 similar to the antenna conductors. 7. The metallic conductor in the recess 77 is immersed in the dielectric 78 and electrically connected via an internal recess to the mass cylinder 74. As before, power is supplied through the coaxial cable 79.
If it is necessary to counteract the transverse propagation mode (TEM), for the reasons indicated, spiral winding of the first antenna element (Fig. 9) in the form of two longitudinal sections, wound with equal pitch and in the opposite direction, is carried out. So, on a dielectric sleeve 80, the inside of which is covered with a metal coating 81 forming a cylindrical mass element, a metal strip 82 is spirally wound, starting from the edge 83 short-closed with the mass cylinder 81, up to the turning point 84 corresponding to the center of the unfolded length aHTeHHjji after which the step of winding is reversed to form turns 85. The edge 86 of this radiating element is short-circuited with the plane of mass. The total antenna length is matched at half the wavelength created in the dielectric sleeve 80. The antenna feeds to two adjacent points along edges 83 and 86 from two coaxial cables in the form of two opposite-phase voltages, respectively. As a result, two connected in series and geometrically opposite quarter-wave antennas are obtained, the current in which, however, has the same direction, which contributes to the study in the desired mode, while the electric fields corresponding to the voltage between the opposite winding sections and the drill string solution, have opposite polarity and create
There are reverse effects seeking to eliminate transmission in TEM mode. In another embodiment, the probe 87 (Fig. 10) comprises a cylindrical body surrounded by an outer metal sheath 88. Around the sheath are two-plate antennas 90 located at several longitudinally spaced locations 89, the type of winding of which coincides with the design shown in Fig. 6.
From the top of FIG. 10, where the probe is shown with a partial cut along the diametrically longitudinal plane,
it can be seen that externally metallic
the shell 88 represents in each place 89 a section 91 of a narrowed outer diameter, which forms a cylindrical mass element for each antenna 90. Each of the narrowed sections 91 is covered by a dielectric sleeve 92, around which a metallic ribbon 93 is wound in a spiral, the edge of which is short-circuited with metal the constricted shell 88 constricted portion 91. The total thickness of the dielectric sleeve and tape 92 93 is such that the diameter of the entire assembly will be less than the diameter of the shell
88 in the sections 94 that separate the positions 89. The sections 94 themselves are interconnected by a series of rods 95 extending from above in the longitudinal direction of the tape 93, thus forming
way lattice from parallel
rods around antennas 90 for the purpose of their metal protection. The longitudinal rods 95 together with the shell 88 form the body. In this embodiment, the cylindrical mass element is in direct electrical contact with the drilling fluid. No TEM distribution can occur when
the absence of a coaxial structure with a dielectric between the inner conductor and the column of the surrounding mud device. In another embodiment, the design
(Fig. 11) the sheath of probe 96 is formed by a metal sheath 97 extending along the entire height of the device. Around the shell 97, transmitting antenna 98 and a number of receiving antennas 99-102 are installed at longitudinally spaced positions. Each of the antennas 98, 99-102 contains a dielectric coating 103, tightly adjacent directly around the outer surface of the shell 97, forming a cylindrical mass element common to all antennas. Around each dielectric sleeve 103 (Fig. 12), a radiating metallic tape 104 is wound in a spiral, electrically connected to the shell 97 at one of its edges 105. The tape 104 is enclosed in an insulating coating 106 based on fiberglass, providing mechanical protection from shock and friction during moving the device inside the borehole, along with chemical corrosion protection. Through the sheath 97, a coaxial cable 107 supplying the antenna 98 passes. The sheath of the cable is electrically connected to the sheath of the probe. The core 108 is connected, as before, to match the impedance.
If the protection performed by the coating 106 is effective from a mechanical and chemical point of view, then from an electrical point of view the protection is not necessary. There will be no TEM emission.
The electronic circuits necessary for the operation of the device are placed in the internal space bounded by the conductive shells 88 and 97 in their upper part (these sections are not shown). On the supports 109 install electronic information processing units connected to pairs of receiving antennas 99, 100 and 101, 102 using coaxial cables 110, 111, 12 and 113.
The structure of the electronic circuits and communications required to power the transmitting antenna 98 and to receive signal processing capability, the arrival of search antennas 99-102, is known in the art 15 J.
Thus, the proposed device is a probe for carrying out logging (diagrams) using electromagnetic wave propagation, which contains a metal sheath and provides, besides suppressing wave propagation in TEM mode, certain advantages in the manufacture of devices both in terms of strength and ease of installation , and, consequently, the cost of manufacture, in particular, with the help of such a probe, it is possible to reduce or take into account the expansion of the coils along the probe body, niemo
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23849 2
The considered variants of the installation of antennas on the body of electromagnetic logging probes present certain advantages compared to those known, especially in comparison with devices where carcasses are used as converters of electromagnetic energy between the device and the environment.
In the proposed transformations, the radiation of antennas, which is several tens, is significantly improved compared with the known structures (5 and sometimes even several hundred times more than the recoil of the previously used coils.
Improvement of antenna parameters is possible not only for the energy emitter, but also for the receivers. With antennas with radiation increased, for example, 50 times, the electrical power corresponding to signals received at the same radiation power is 2500 times greater. Such an increase in useful power that can be used to radiate the propagation of electromagnetic waves could not be achieved by the technical means used up to now.
This improvement has many advantages, for example, it can be used to simplify electronic obscuration circuits that interact with receiving antennas 15-18 (Fig. 1). This significant improvement in radiation was obtained with antennas having dimensions of the same order as previously used, with the new antennas being adapted to the typical diameter of the logging body. Unlike coil converters, whose efficiency increases with the diameter, the output of the proposed antennas, and with it the amount of energy that can be transmitted when these antennas are radiated, depends on their diameter. A significant improvement in antenna efficiency is accompanied by an increase in the space available for the placement of electronic equipment, even if the radiator is powered by powerful conductors running from the surface. 55 Therefore, the overall length of the device can be reduced. The high return rate of these antennas makes it possible not to be afraid of a slight deterioration.
35
40
45
50
33
recoil, which may occur when improving other properties of the device.
The increase in radiated power makes it possible to apply methods of exploration of geological formations by means of the propagation of electromagnetic waves with much more conductive drilling rigs than before. The attenuation of waves propagating in the medium depends on the conductivity of the latter. The proposed device makes it possible to operate with a significantly greater attenuation of the radiated energy in the surrounding drilling mud than it was before, without reducing the total amount of energy that can be detected by the receivers. It is possible to work in drilling fluids, whose electrical resistivity reaches 0.05 Ω x m, which makes it possible to expand the use of devices of this type to almost all drilling fluids currently used. At the same time, the need to increase the diameter of the device to limit the thickness of the column of drilling fluid crossed by radiation during transmission and reception disappears.
Another advantage of a significant increase in radiated power is based on an increase in the signal-to-noise ratio in the receivers, which makes it possible to increase the detection accuracy when using more robust and reliable electronic circuits to obtain the required information. In addition, with antennas of this type, a conductive tube can be used that runs along the entire length of the probe and acts as a shield for the sensitive elements of these antennas without the occurrence of unwanted wave propagation in TEM mode due to the presence of various means.
A probe equipped with the proposed antennas improves the resolution of the reconnaissance while maintaining the required depth. The depth of exploration depends on the distance between the transmitter and receiver, while the resolution depends on the distance between the receivers of each pair. Measurements made by each pair of receivers are differential measurements of changes in some propagation parameters, such as
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2384934
Chania or phase shift introduced by a certain zone of a geological formation whose tolgtsin is determined by the spacing of these receivers. The smaller the spacing between the receivers, the smaller the thickness of this zone, and, therefore, the greater the resolution of the measurement being taken. The spacing of the receivers of one pair must be maintained at a value IQ sufficient for the electronic measurement and processing circuits to note the difference between For the same reason, if it is necessary to detect a phase difference of the order of a fraction of a degree, the spacing of the receivers should be sufficient so that the oscillation of this parameter between the two formations is different. ode represents whether at least the value of the thickness of the considered formation. In this case, the same thing happens with attenuation.
jc To increase the resolution, it is necessary to achieve an increase in the measured attenuation and phase shift of electromagnetic waves propagating in the formation zone of a given thickness, which can be achieved by increasing the operating frequency of the device. However, an increase in the frequency gives a significant attenuation of signals, therefore, the radiated power must be much larger when measured at the level of power receivers that are still sufficient for their detection and appropriate processing. This can be accomplished with the help of devices equipped with the proposed bla4® godar antennas to significantly increase the radiated energy. At the same time, with a typical radiation generator power, it is possible to create such high power that it turns out to be permissible
43 significantly greater attenuation, in particular, when operating at frequencies much higher than in known devices, along with maintaining the receiving signal level at the input
50 receivers for the actual detection and measurement. This result is achieved while maintaining a considerable depth of exploration, which encompasses the path of electromagnetic waves from the radiator to the receiver, over which the attenuation of a signal at a relatively high frequency can be significant.
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35
The power radiated by antennas of the presented type is quite sufficient to reach a depth of reconnaissance in the order of one to two meters with antennas mounted on the body of the probe, and in the frequency range from 60 to 80 MHz. The resolution that can be achieved at this operating frequency is from about 60 cm to 1 meter. By increasing the operating frequency up to several tens of megahertz, windings can be obtained on the probe cases with a useful length equal to half a wavelength and to a wavelength, since the wavelength decreases with increasing frequency, it is possible to match the developed length of the probe for a given antenna length dimension element with a larger fraction of the radiation wavelength. In a relatively low frequency range, the antenna length is rotated, necessary to obtain matching with a quarter of the electromagnetic wavelength, t turn out to be invalid. However, improving the antenna performance, all other parameters being equal, is enough to make it possible to use them at frequencies below 20 MHz, up to 1 MHz. At these frequencies, the means for reducing the effective length of the radiating element wound around the body (the first conductive element) consists in modifying the connections between this element and the mass element.
The radiating winding of a double-plate antenna 114 formed by a metal tape 115 (Fig. 12) has a developed length of less than a quarter of the wavelength. Instead of short-circuiting with the plane of mass 116, the edge 117 of the tape 115 is connected to the plane of the mass 116 using an inductance 118, the dimensions of which are chosen so that the resonating node formed by the radiating tape 115 and the inductance 118 and connected by parallel running capacitance between two conductive elements of the tape 115 and the plane of mass 116, formed the tuning scheme for the frequency in question. The switching point 119 is connected to the generator 120. The other end 121 of the tape 115 is electrically free.
According to one embodiment of the design (FIG. 13) of the antenna on the housing 121, designed to operate at relatively low frequencies, the radiating element 122 is deployed
ten
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less than a quarter of the wavelength of the radiation in the dielectric 123 at the considered frequency has at one of the ends 124 a short-circuit jumper with the plane of mass. Its other end 125 is connected to the plane of mass 126 through a capacitor 127, the value of which is chosen so that the equivalent circuit of the radiating element 122 and the capacitor 127 connected to the running capacity existing between the element 122 and the plane of mass 126, constitutes a circuit operating frequency of the generator 120.
Another means of reducing the effective length of the radiating element wound around the probe body, which can be combined with the preceding one, is to use a material with high magnetic permeability instead of a dielectric between the two conductive antenna elements. When the dielectric constants of conventional materials vary from 1 to 20 as compared with air, the magnetic permeability of some materials, compared to the magnetic permeability of air, can reach several thousand hours at a relatively low frequency, Too at a frequency of not more than a few tens of megahertz .
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From equation (5) you can see that the wavelength varies back
proportional to the square root of the magnetic permeability. Under these conditions, antennas operating in the frequency range below several tens of megahertz can be obtained by selecting a magnetic material with a sufficiently high Curie point so that it retains a high magnetic permeability value over the entire temperature range of devices used.
for logging boreholes. Therefore, when using a ferromagnet whose magnetic permeability is about 250, it is possible to obtain an antenna with the first element applied to
The outer surface of the sleeve is made of this material, while the plane of the maye is applied to the inner surface. When creating an antenna with a deployed length of 38 m, corresponding to a quarter of the wavelength in this material (as compared to 600 m in vacuum), such an antenna can be made to work at a frequency of 500 kHz.
The required antenna length can be achieved by using a winding of 120 turns on a case with a diameter of 10 cm.
 As a result, a logging tool is obtained using electromagnetic radiation suitable for operating at a relatively low frequency, below 1 MHz, when environmental measurements are significantly affected by measurements of relative propagation parameters and the dielectric constant of these media has a relatively small effect. With the placement of the antenna on the metal case of the probe, a new means for measuring conductivity is obtained, which, unlike classical devices, does not require the use of an insulating case for the greater part of its length. The advantages of a new type of device are simplicity, durability and dimensional stability.
In addition, the proposed design allows a device for measuring conductivity to be combined with a device for measuring resistivity on electrodes, connecting antennas of the specified type operating at relatively low frequencies and located around a metal housing with electrodes, for example, from a pseudo-sided device,
A new combined device of this type (FIG. 18) contains a probe 128 on which a central electrode 129 is installed. On the one and the other side of the electrode 129, two pairs of potential measuring electrodes 130, 131 and 132, 133 are located symmetrically, after which the first current electrodes 134 and 135 follow, then the second current electrodes 136 and 137. All these electrodes are formed of conductive rings mounted on the surface of the case, the electrodes 136 and 137 having the form of elongated sleeves. for powering and controlling the electrodes are known, they allow the currents between the electrodes 129, 134 and 136 and 129, 135 and 137 to be passed and areas remote from the device in the environment, adjusting the currents so that the potential difference between the measuring electrodes 130 and 131 and between electrodes 132 and 133 will remain zero.
The left part of the device shows the current lines 138 in the formation under study when examining the near zone of the well and the right part shows the path of the current lines when exploring the far zone of the well when the current lines return to the borehole to a point remote from the electrode complex of the device, for example, to the electrode a mass (not shown) located on the cable 139 of the probe 128. The currents generated by the electrodes 134, 136, 135, 137 are adjusted to increase the current generated by the electrodes 129 more or less far in the formation in accordance with the required depth of study.
A two-plate antenna 140 of the type considered, which coincides, for example, with the antenna design,
shown in FIG. 6 is installed from the edge of the electrode complex below electrode 137. It is connected to a generator operating at a frequency
500 kHz for transmitting radiation of the appropriate frequency to the geological formation under study.
Two receiving dual-plate antennas 141 and 142 are installed: the first between the electrodes 135 and 137 and the second between the electrodes 134 and 136. The receiving antennas are connected to the electronic detection circuits and the usable / received signals
after propagation in the studied formation to obtain a differential measurement of conductivity. The combination of measurements made with antennas 141 and 142 makes it possible to
obtaining such a differential measurement of conductivity, which corrects the influence of the zone immediately adjacent to the device,
those. the well itself, the well, and the outer zone around the wall of the well. Antennas 140, 141, 142 have a common mass plane at a frequency of 500 kHz. All current electrodes 129, 134-137 are electrically connected to said mass plane. Thus, the plane of mass is in electrical contact with the drilling fluid at various points along its length. At the same time, in the plane of the mass, there exists an appropriate capacitive coupling between its various parts so that at the working frequency of the pseudo-side device
With a log of several hundred hertz, these electrodes were not electrically connected to the plane of mass.
The radiating elements of the antenna 140, 141 and 142 are, for example, of the element 53 (FIG. 6). They are applied to a sleeve of the sleeve 54 of ferromagnetic material with magnetic permeability of about 250.
Such a device can successfully replace known logging devices using those functions that are performed on coils for radiating current into surrounding formations. In order to avoid current pickup on the ring electrodes, which distorts measurements made using induction coils, each electrode of such a device is performed as a sequence of round protrusions surrounding the probe body, on its surface as o
The use of two-plate antennas makes it possible to refuse round electrodes and allows the use of massive, deeper electrodes. The characteristics of the device for measuring conductivity with two-plate antennas (Fig. 18) are improved compared with the device on the coils in terms of better vertical resolution and less influence on the medium in the well bore due to the differential nature of the measurements, as well as significantly higher level signals.
The use of the described antennas for electromagnetic logging is possible at other frequencies of the used spectrum, in particular at frequencies above 200 MHz. Considered antennas, due to their extremely simple design, apart from the enclosures of the devices, can be placed on the shoes of microinstallations when operating at higher frequencies. With increasing frequency, it is preferable to mount the antenna on shoes that are of a size compatible with a relatively shallow depth of exploration.
In one embodiment, such antennas can be implemented in the form of round disks, similar to buttons (Fig. 14), in which a plate of dielectric material 143 is covered on one of its sides
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a conductive metal layer 144 forming a mass plane, and on the opposite side 145 a thin metal strip in the shape of a spiral 146 is printed, one end 147 of which can be electrically short-circuited connected to the mass plane in the center, and the other end 148 remains free if the length is printed helix is equal to quarter
the propagation wavelength in dielectric material 143 or an odd multiple of the latter, this strip is short-circuited with; by the plane of mass, by the layer 144, if the length of the helix is turned equal to a number multiple of half the propagation wavelength. Antennas of this type can be embedded in an elongated shoe 149, (FIG. 16), which at each of its edges has radiating antennas 150 and 151 connected to a very high frequency power generator (shown in the drawing). O Between two radiating antennas 150 and 151 adjacent to the central part of the bag, three receivers 152, 153 and 154 are installed, mounted in the longitudinal direction of the shoe. The shoe 149 is installed (FIG. 1) in a known manner on the probe 13 and articulates to allow the lever 155 to be pressed against the borehole wall 2 under the action of a constant elastic force generated by the arcuate springs or by means of a lever, the opening of which is remotely controlled
The arrangement of the two radiating antennas 150 and 151 (Fig. 16) is used to compensate for the effects of non-uniform clamping of the shoe against the wall of the trunk if there are irregular shapes in the latter. Compensation methods
5 Effects of the borehole
(VNS compensation) in devices operating with various types of transducers are known.
Depicted in FIG. 16 shoe
0 149 operates in the frequency range 60-MHz-3 GHz (ultrahigh frequencies) and can be used in a device to determine the angle of incidence of the formations. Measurements obtained with receiving antennas5 of detectors 152-154 allow high-resolution detection of changes in dielectric signals. properties of formation formations intersected borehole0
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0
Noah. In accordance with the known methods of tilt measurement, the set of indications obtained from three, preferably from four similar shoes, applied in the borehole wall, allows to determine the slope of separation planes of adjacent formations. Dual-plate antennas of the type described can be successfully used with the device in boreholes filled with unsalted water or oil-based drilling fluids, where conventional devices on electrodes cannot work. Moreover, the device of FIG. 1, provided with the antennas of the shoe 149., allows for each position of the shoe 149 to conduct conductivity and dielectric constant measurements that are used to correlate the measurements with each other and improve the efficiency of data utilization. Due to this, an extremely accurate representation of all changes in their geological properties, cracks and other interruptions of formations intersected by a borehole is achieved.
The invention can also be applied in the shoes for transmitting and receiving electromagnetic energy of ultrahigh frequency (Fig. 17). The shoe 156 is provided at the lower edge of the transmitting antenna 157 made in a two-plate technique and contains a metal ring 158 printed on the dielectric forming the surface of the shoe 156, and electrically connected at 159 with a mass plane placed on the other side of the dielectric surface. The perimeter of the ring corresponds to the formation of a half-wave antenna whose working frequency can be, for example, 850 MHz. Two receivers located at the other edge of the shoe are formed by two strips 160 and 161 aligned on the surface of the shoe in its longitudinal direction and in the direction of the antenna 157, Strips 160 and 161 electrically connecting one of the edges 162 and 163 to the plane of mass, forming the surface of the shoe. The length of the strips corresponds to a quarter of the wavelength of the frequency used. Such a shoe allows certain radiation parameters of the electromagnetic energy emitted by the radiating antenna.
23849 2
157 near the borehole walls, especially in the mud cake during its implementation.
The proposed antennas can also be used for various studies in the range and even higher frequencies, for example 200-500 MHz.
For this, the batmac 164 (Fig. 15) for the near zone study makes Q c out of an insulating plate made of a material resistant to abrasion, for example, a mixture of fiberglass and resin, and the plate is made elongated in the direction
and corresponding longitudinal movement relative to the borehole wall. The shoe contains an internal radiating antenna 165, the top of which is in the longitudinal direction
2Q two receiving antennas 166 and 167. On the rear surface, t, e. a surface not facing the geological formation, there is a continuous metallic coating forming a plane
25 masses and a closed shell to protect against the action of drilling fluids washing the shoe. In addition to the plane of the mass and dielectric layer, the antenna contains a metal plate 168, 166 and 167, respectively, printed on the surface 169 of the shoe along a spiral path made up of straight line segments, joined at specific angles to cover a significant portion of the surface of the shoe.
An antenna 165 occupies the lower portion, the printed metal plate 168 of this antenna is short-circuited with the plane of mass at its central end 170 and at the peripheral end 171, the antenna length is calculated to produce a half-wave antenna. The central end of each receiving antenna, respectively 172 and 173, is short-circuited with the mass plane on the back surface of the shoe, while the other ends of the metal plates of these antennas are left free, and their length is equal to a quarter of the wavelength of the radiation under consideration.
Of particular interest is the use in drilling fluids based on non-saline water or oil shoes when the shoes are with.
55 electrodes do not work, its difference is not so much sensitivity to the specific resistance of the drilling mud due to diff
40
45
50
It provides more accurate information on the formation resistivity of the formation, Measuring the dielectric constant near the borehole wall allows to find saturation in the water ovv in an area called the flushed zone where under the action of the pressure of the drilling fluid in contact with the wall of the barrel its filtrate after sedimentation of solid particles about
nicks into the borehole wall to form a mudcake, moving some of the hydrocarbons that may be in the pores of this formation.
It is desirable that the metal parts of the antennas on the shoes shown in FIG. 14-17, be coated with a protective coating to obtain greater resistance to mechanical abrasion and corrosion.
FIG. 2
0
38
four/
FIG.
Figm
7
78 77 76
7J
Fig.e
85
FIG. 9
thirty
FIG .. JO
58
97
X
S6
.eleven
/ "/ F
/ 47
FIG. fS
It
ff
- 171
FIG IS
til
 m
153
Ig
/ -tso
viy
FIG. 17
161 I r

160
 r
V / v
158 - FIG. 18
, IS
VNIIPI Order 1728/62 Circulation 728 Subscription Branch PPP Patent, Uzhgorod, ul. Project, 4

权利要求:
Claims (4)
[1]
1. DEVICE FOR ELECTROMAGNETIC LOGGING OF A DRILLING WELL, comprising a probe for moving in a borehole, electrodes connected to an electrical circuit located in this probe for converting electrical signals generated in the probe and electromagnetic energy signals propagating in the environment, characterized in that that, in order to improve the accuracy of measuring the characteristics of the propagation of electromagnetic waves in the environment surrounding the borehole of the well intersecting geological formations, the probe has πος. at least one antenna containing an elongated electrode, and an electrode located opposite and at a predetermined distance from the elongated electrode along the entire useful length of the latter, while the opposite sections of the elongated electrode and the electrode are separated by an insulator and electrically connected to one another at one end of the length of the elongated electrode moreover, the end of the elongated electrode is electrically connected to the electrode using an inductor, the elongated electrode is placed along a curved path parallel to a given ited insulator, the electrode and parallel to this surface the elongate electrode is disposed on the outer side of the probe.
[2]
2. The device pop. 1, characterized in that the electrical connection between the electrodes is made in the form of a short-circuited jumper, and the useful length of the elongated electrode, counted from its short-circuited end, is selected as a function of the propagation wavelength of electromagnetic energy of a given frequency in the insulator.
[3]
3. The device according to paragraphs. 1 and 2, characterized in that the antenna is connected by an electric cable for transmitting electromagnetic energy with a predetermined frequency between the antenna and the electric circuit in the probe, with the sheath of the coaxial cable connected to the electrode and the electrical core to the elongated electrode in the place necessary for matching impedance antenna with impedance coaxial cable.
[4]
4. The device according to paragraphs. 1-3, characterized in that the electrode is made in the form of a plane parallel to the surface of the insulator, on which · an elongated electrode is placed along a curved path.

类似技术:

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公开号 | 公开日 | 专利标题

---

SU1223849A3|1986-04-07|Device for electromagnetic logging of borehole

---

US4536714A|1985-08-20|Shields for antennas of borehole logging devices

---

USRE32913E|1989-04-25|Shields for antennas of borehole logging devices

---

US4489276A|1984-12-18|Dual-cone double-helical downhole logging device

---

AU765066B2|2003-09-04|Method and apparatus for cancellation of borehole effects due to a tilted or transverse magnetic dipole

---

US4814768A|1989-03-21|Downhole pulse radar

---

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---

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---

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---

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---

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---

US5442294A|1995-08-15|Conductivity method and apparatus for measuring strata resistivity adjacent a borehole

---

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---

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---

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---

US4845433A|1989-07-04|Apparatus for microinductive investigation of earth formations

---

GB2250098A|1992-05-27|Measuring tool incorporating broadband stripline aerials and useful in well logging

---

WO2008095619A1|2008-08-14|An antenna of an electromagnetic probe for investigating geological formations

---

US4780678A|1988-10-25|Apparatus for microinductive investigation of earth formations

---

US2455941A|1948-12-14|Geophysical prospecting in boreholes by microwaves

---

US4651100A|1987-03-17|Antenna construction for well logging of subsurface earth formations

---

US4712070A|1987-12-08|Apparatus for microinductive investigation of earth formations

---

US3449657A|1969-06-10|Helical antenna for irradiating an earth formation penetrated by a borehole and method of using same

---

US4739272A|1988-04-19|Apparatus for microinductive investigation of earth formations with improved electroquasistatic shielding

---

US4678997A|1987-07-07|Method and apparatus for dielectric well logging of subsurface earth formations with a lumped constant antenna

同族专利:

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公开号 | 公开日

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ES506289A0|1983-02-01|

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CA1183207A|1985-02-26|

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JPS5796282A|1982-06-15|

---

FR2492540A1|1982-04-23|

---

IN155566B|1985-02-16|

---

AU7612681A|1982-04-22|

---

ES8303715A1|1983-02-01|

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EP0051018A1|1982-05-05|

---

OA06926A|1983-05-31|

---

FR2492540B1|1984-09-14|

---

EP0051018B1|1985-07-03|

---

DE3171244D1|1985-08-08|

---

BR8106663A|1982-07-13|

---

AU548579B2|1985-12-19|

---

NO813501L|1982-04-19|

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US4511843A|1985-04-16|

---

MX151154A|1984-10-04|

引用文献:

---

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

---

RU2452982C2|2006-09-28|2012-06-10|Бейкер Хьюз Инкорпорейтед|Interpretation of wide-band resistivity data|CA777913A|1968-02-06|B. Jones Stanley|Method for mapping salt domes at depth|

---

US3124742A|1964-03-10|Apparatus for investigating earth formations having an |

---

US2857451A|1952-08-08|1958-10-21|Socony Mobil Oil Co Inc|Case for well logging tools|

---

US2723375A|1953-03-02|1955-11-08|Schlumberger Well Surv Corp|Induction logging apparatus|

---

US3052837A|1958-12-24|1962-09-04|Shell Oil Co|Pipe finder|

---

US3094658A|1959-03-17|1963-06-18|Halliburton Co|Logging system using electrostatically shielded coils|

---

US3214686A|1960-09-06|1965-10-26|Newmont Mining Corp|Drill hole electromagnetic method and apparatus for geophysical exploration utillizing in-phase and out-of-phase nulling voltages|

---

US3408561A|1963-07-29|1968-10-29|Arps Corp|Formation resistivity measurement while drilling, utilizing physical conditions representative of the signals from a toroidal coil located adjacent the drilling bit|

---

US3305771A|1963-08-30|1967-02-21|Arps Corp|Inductive resistivity guard logging apparatus including toroidal coils mounted on a conductive stem|

---

FR1527757A|1966-09-29|1968-06-07|Schlumberger Prospection|Electromagnetic device for measuring the resistivity of formations crossed by a sounding|

---

US3629937A|1966-11-14|1971-12-28|Chevron Res|Method of forming a helical antenna|

---

US3582766A|1969-11-13|1971-06-01|Keigo Iizuka|Passively controlled duplexer-coupler applied to a helical antenna for use in a borehole penetrating an earth formation|

---

US3803623A|1972-10-11|1974-04-09|Minnesota Mining & Mfg|Microstrip antenna|

---

US3894283A|1972-11-03|1975-07-08|Schonstedt Instrument Co|Magnetic locator including sensors mounted in longitudinal grooves of a tubular support|

---

US3780373A|1972-11-21|1973-12-18|Avco Corp|Near field spiral antenna|

---

IE39998B1|1973-08-23|1979-02-14|Schlumberger Inland Service|Method and apparatus for investigating earth formations|

---

US4012689A|1974-10-24|1977-03-15|Texaco Inc.|Radio frequency resistivity and dielectric constant well logging utilizing phase shift measurement|

---

US4107598A|1976-02-02|1978-08-15|Texaco Inc.|Electromagnetic wave logging system for determining resistivity and dielectric constant of earth formations|

---

US4107597A|1976-12-13|1978-08-15|Texaco Inc.|Electromagnetic wave propagation well logging utilizing multiple phase shift measurement|

---

US4185238A|1977-09-21|1980-01-22|Schlumberger Technology Corporation|Apparatus and method for determination of subsurface permittivity and conductivity|

---

US4204212A|1978-12-06|1980-05-20|The United States Of America As Represented By The Secretary Of The Army|Conformal spiral antenna|

---

US4319191A|1980-01-10|1982-03-09|Texaco Inc.|Dielectric well logging with radially oriented coils|

---

US4401947A|1980-09-26|1983-08-30|Texaco Inc.|Small hole well logging sonde and system with transmitter and receiver assemblies|US4785247A|1983-06-27|1988-11-15|Nl Industries, Inc.|Drill stem logging with electromagnetic waves and electrostatically-shielded and inductively-coupled transmitter and receiver elements|

---

US4808929A|1983-11-14|1989-02-28|Schlumberger Technology Corporation|Shielded induction sensor for well logging|

---

US4626785A|1984-02-24|1986-12-02|Shell Oil Company|Focused very high frequency induction logging|

---

US4651101A|1984-02-27|1987-03-17|Schlumberger Technology Corporation|Induction logging sonde with metallic support|

---

US4873488A|1985-04-03|1989-10-10|Schlumberger Technology Corporation|Induction logging sonde with metallic support having a coaxial insulating sleeve member|

---

AT379864B|1984-03-15|1986-03-10|Prakla Seismos Gmbh|DRILL HOLE MEASURING DEVICE|

---

GB2156527A|1984-03-30|1985-10-09|Nl Industries Inc|Aperture antenna system for measurement of formation parameters|

---

EP0183816A1|1984-06-16|1986-06-11|GenesisLimited|Collar assembly for telemetry|

---

GB2166599B|1984-11-02|1988-06-08|Coal Ind|Borehole located directional antennae means for electromagnetic sensing systems|

---

JPS61277080A|1985-05-30|1986-12-08|Schlumberger Overseas|Micro-induction type test apparatus for bed|

---

US4831331A|1987-04-10|1989-05-16|Chevron Research Company|Method and apparatus for interface location determination|

---

US4949045A|1987-10-30|1990-08-14|Schlumberger Technology Corporation|Well logging apparatus having a cylindrical housing with antennas formed in recesses and covered with a waterproof rubber layer|

---

US4899112A|1987-10-30|1990-02-06|Schlumberger Technology Corporation|Well logging apparatus and method for determining formation resistivity at a shallow and a deep depth|

---

US4968940A|1987-10-30|1990-11-06|Schlumberger Technology Corporation|Well logging apparatus and method using two spaced apart transmitters with two receivers located between the transmitters|

---

US5233522A|1989-07-21|1993-08-03|Halliburton Logging Services, Inc.|Multifrequency dielectric logging tool including antenna system responsive to invaded rock formations|

---

US5081419A|1990-10-09|1992-01-14|Baker Hughes Incorporated|High sensitivity well logging system having dual transmitter antennas and intermediate series resonant|

---

EP0539118B1|1991-10-22|1997-12-17|Halliburton Energy Services, Inc.|Method of logging while drilling|

---

US5453693A|1993-10-01|1995-09-26|Halliburton Company|Logging system for measuring dielectric properties of fluids in a cased well using multiple mini-wave guides|

---

US5530358A|1994-01-25|1996-06-25|Baker Hughes, Incorporated|Method and apparatus for measurement-while-drilling utilizing improved antennas|

---

US5563512A|1994-06-14|1996-10-08|Halliburton Company|Well logging apparatus having a removable sleeve for sealing and protecting multiple antenna arrays|

---

US5459697A|1994-08-17|1995-10-17|Halliburton Company|MWD surface signal detector having enhanced acoustic detection means|

---

US5515336A|1994-08-17|1996-05-07|Halliburton Company|MWD surface signal detector having bypass loop acoustic detection means|

---

GB9417450D0|1994-08-25|1994-10-19|Symmetricom Inc|An antenna|

---

US5594343A|1994-12-02|1997-01-14|Schlumberger Technology Corporation|Well logging apparatus and method with borehole compensation including multiple transmitting antennas asymmetrically disposed about a pair of receiving antennas|

---

GB9524977D0|1995-12-06|1996-02-07|Integrated Drilling Serv Ltd|Apparatus for sensing the resistivity of geological formations surrounding a borehole|

---

GB9601250D0|1996-01-23|1996-03-27|Symmetricom Inc|An antenna|

---

US5900733A|1996-02-07|1999-05-04|Schlumberger Technology Corporation|Well logging method and apparatus for determining downhole Borehole fluid resistivity, borehole diameter, and borehole corrected formation resistivity|

---

US5963036A|1996-02-07|1999-10-05|Schlumberger Technology Corporation|Well logging apparatus and method for determining properties of earth formations that have been invaded by borehole fluid|

---

GB9603914D0|1996-02-23|1996-04-24|Symmetricom Inc|An antenna|

---

US5886526A|1996-06-19|1999-03-23|Schlumberger Technology Corporation|Apparatus and method for determining properties of anisotropic earth formations|

---

US5924499A|1997-04-21|1999-07-20|Halliburton Energy Services, Inc.|Acoustic data link and formation property sensor for downhole MWD system|

---

US6102115A|1998-01-23|2000-08-15|Schlumberger Technology Corporation|Integral standoff of induction sondes to minimize correction of borehole conductivity effects|

---

US6191586B1|1998-06-10|2001-02-20|Dresser Industries, Inc.|Method and apparatus for azimuthal electromagnetic well logging using shielded antennas|

---

GB9813002D0|1998-06-16|1998-08-12|Symmetricom Inc|An antenna|

---

GB9828768D0|1998-12-29|1999-02-17|Symmetricom Inc|An antenna|

---

GB9902765D0|1999-02-08|1999-03-31|Symmetricom Inc|An antenna|

---

GB9912441D0|1999-05-27|1999-07-28|Symmetricon Inc|An antenna|

---

GB9913526D0|1999-06-10|1999-08-11|Harada Ind Europ Limited|Multiband antenna|

---

US6581454B1|1999-08-03|2003-06-24|Shell Oil Company|Apparatus for measurement|

---

US6483310B1|1999-11-22|2002-11-19|Scientific Drilling International|Retrievable, formation resistivity tool, having a slotted collar|

---

US6901654B2|2000-01-10|2005-06-07|Microstrain, Inc.|Method of fabricating a coil and clamp for variable reluctance transducer|

---

US6573722B2|2000-12-15|2003-06-03|Schlumberger Technology Corporation|Method and apparatus for cancellation of borehole effects due to a tilted or transverse magnetic dipole|

---

US6644421B1|2001-12-26|2003-11-11|Robbins Tools, Inc.|Sonde housing|

---

US6667620B2|2002-03-29|2003-12-23|Schlumberger Technology Corporation|Current-directing shield apparatus for use with transverse magnetic dipole antennas|

---

US6791330B2|2002-07-16|2004-09-14|General Electric Company|Well logging tool and method for determining resistivity by using phase difference and/or attenuation measurements|

---

US7212173B2|2003-06-30|2007-05-01|Schlumberger Technology Corporation|Flexcircuit axial coils for a downhole logging tool|

---

US7053789B2|2003-07-31|2006-05-30|Radiodetection Limited|Underground object locator|

---

US7034768B2|2003-09-24|2006-04-25|Gas Technology Institute|Antenna system|

---

US7026813B2|2003-09-25|2006-04-11|Schlumberger Technology Corporation|Semi-conductive shell for sources and sensors|

---

US7825664B2|2004-07-14|2010-11-02|Schlumberger Technology Corporation|Resistivity tool with selectable depths of investigation|

---

CA2476787C|2004-08-06|2008-09-30|Halliburton Energy Services, Inc.|Integrated magnetic ranging tool|

---

BRPI0518347B1|2004-11-19|2017-12-19|Halliburton Energy Services, Inc.|METHOD FOR CONNECTING UNDERGROUND ROAD, AND, WELL HOLE NETWORK|

---

US7348781B2|2004-12-31|2008-03-25|Schlumberger Technology Corporation|Apparatus for electromagnetic logging of a formation|

---

US7671597B2|2005-06-14|2010-03-02|Schlumberger Technology Corporation|Composite encased tool for subsurface measurements|

---

US20070131412A1|2005-06-14|2007-06-14|Schlumberger Technology Corporation|Mass Isolation Joint for Electrically Isolating a Downhole Tool|

---

US7342554B2|2005-11-25|2008-03-11|Inpaq Technology Co., Ltd.|Column antenna apparatus and a manufacturing method thereof|

---

WO2007149106A1|2006-06-19|2007-12-27|Halliburton Energy Services, Inc.|Antenna cutout in a downhole tubular|

---

US8203344B2|2006-09-14|2012-06-19|Baker Hughes Incorporated|Method and apparatus for resistivity imaging in boreholes with an antenna and two spaced apart electrodes|

---

US7876102B2|2006-09-14|2011-01-25|Baker Hughes Incorporated|Mixed galvanic-inductive imaging in boreholes|

---

US7742008B2|2006-11-15|2010-06-22|Baker Hughes Incorporated|Multipole antennae for logging-while-drilling resistivity measurements|

---

US20100283468A1|2008-06-27|2010-11-11|John Signorelli|Remotely located tuning circuits for multi-frequency, multi-puropse induction antennae in downhole tools|

---

EP2148224A1|2008-07-23|2010-01-27|Nederlandse Organisatie voor toegepast-natuurwetenschappelijk Onderzoek TNO|Determining earth properties|

---

RU2524835C2|2008-08-22|2014-08-10|Дьюк Юниверсити|Surface and waveguide metamaterials|

---

US9709692B2|2008-10-17|2017-07-18|Baker Hughes Incorporated|Method and apparatus for borehole wall resistivity imaging with full circumferential coverage|

---

US20130239673A1|2010-06-24|2013-09-19|Schlumberger Technology Corporation|Systems and Methods for Collecting One or More Measurements in a Borehole|

---

US10114140B2|2010-08-26|2018-10-30|Schlumberger Technology Corporation|Apparatus and method for microresistivity imaging in which transmitter coil and receiver coil axes are substantially perpendicular to the longitudinal axis of the tool body|

---

US11078409B2|2013-05-17|2021-08-03|Conocophillips Company|Electrically conductive proppant coating and related methods|

---

FR3008550B1|2013-07-15|2015-08-21|Inst Mines Telecom Telecom Bretagne|STOP-TYPE ANTENNA AND ANTENNA STRUCTURE AND ANTENNA ASSEMBLY THEREOF|

---

GB2536532A|2013-09-03|2016-09-21|Halliburton Energy Services Inc|Deep sensing systems|

---

WO2015152758A1|2014-04-02|2015-10-08|Baker Hughes Incorporated|Imaging of earth formation with high frequency sensor|

---

EP3012670A1|2014-10-22|2016-04-27|Services Petroliers Schlumberger|Flat metallic strip toroidal coil|

---

GB2543356B|2015-10-16|2019-11-27|Reeves Wireline Tech Ltd|Apparatuses and methods for determining permittivity in downhole locations|

---

WO2017082929A1|2015-11-13|2017-05-18|Halliburton Energy Services, Inc.|Microstrip antenna-based logging tool and method|

---

GB2563872A|2017-06-28|2019-01-02|Kirintec Ltd|Communications system|

---

RU2733101C1|2020-03-10|2020-09-29|Общество С Ограниченной Ответственностью "Русские Универсальные Системы"|Sealing assembly of probe for electric logging and probe comprising sealing assembly|

---

RU2758580C1|2020-12-02|2021-10-29|Федеральное государственное бюджетное учреждение науки Институт геофизики им. Ю.П. Булашевича Уральского отделения Российской академии наук|Borehole device for measuring the electrical conductivity and magnetic susceptibility of rocks|

---

RU2762821C1|2020-12-04|2021-12-23|Федеральное государственное бюджетное учреждение науки Институт геофизики им. Ю.П. Булашевича Уральского отделения Российской академии наук|Device for measuring magnetic susceptibility and electrical conductivity of rocks in wells|

法律状态:

优先权:

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申请号 | 申请日 | 专利标题

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FR8022327A|FR2492540B1|1980-10-17|1980-10-17|

---