CN111337988A - Downhole time domain electromagnetic multi-component remote detection instrument - Google Patents

Downhole time domain electromagnetic multi-component remote detection instrument Download PDF

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CN111337988A
CN111337988A CN202010253077.5A CN202010253077A CN111337988A CN 111337988 A CN111337988 A CN 111337988A CN 202010253077 A CN202010253077 A CN 202010253077A CN 111337988 A CN111337988 A CN 111337988A
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time domain
component
module
instrument
power switch
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余刚
肖占山
朱万华
刘丽华
赵宁
闫彬
陈娟
王熙明
夏淑君
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Optical Science and Technology Chengdu Ltd of CNPC
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01VGEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/18Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation specially adapted for well-logging
    • G01V3/26Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation specially adapted for well-logging operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device
    • G01V3/28Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation specially adapted for well-logging operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device using induction coils
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01CMEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C21/00Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
    • G01C21/10Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration
    • G01C21/12Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning
    • G01C21/16Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning by integrating acceleration or speed, i.e. inertial navigation
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01VGEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/38Processing data, e.g. for analysis, for interpretation, for correction

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Abstract

The invention discloses a downhole time domain electromagnetic multi-component far detection instrument, which aims to solve the problem that the existing induction electromagnetic logging instrument based on the frequency domain electromagnetic induction principle only has a very limited detection distance; the apparatus of the present invention comprises: the high-strength nonmagnetic stainless steel or alloy or composite material shell, a three-component time domain electromagnetic emission module, a multi-stage array time domain electromagnetic signal receiving module, a multi-stage array time domain magnetic field signal acquisition unit, a multi-stage array time domain electric field signal acquisition unit, a three-component optical fiber inertial navigation positioning and orienting module, an analog-to-digital conversion module and a memory, wherein the three-component time domain electromagnetic emission module, the multi-stage array time domain electromagnetic signal receiving module, the multi-stage array time domain magnetic field signal acquisition unit; the three-component optical fiber inertial navigation positioning and orienting module is arranged in the middle of the instrument and is used for acquiring the real-time azimuth, moving speed, position and inclination angle of the instrument; the instrument of the invention can adopt a shorter time domain instrument length to achieve the long-distance detection which can be realized by a longer frequency domain electromagnetic induction instrument, thereby reducing the manufacturing cost of the detection instrument and simplifying the underground operation flow.

Description

Downhole time domain electromagnetic multi-component remote detection instrument
Technical Field
The invention belongs to the technical field of geophysical exploration, and particularly relates to an underground time domain electromagnetic multi-component far detection instrument.
Background
The remote detection capability of the downhole electromagnetic logging instrument is helpful for solving the problems of oil-gas reservoir structure and oil-gas-water distribution in the exploration and development of oil-gas resources. In the past 20 years, various oil companies and service companies have conducted many investigations and summarized applications, such as edge detection, water avoidance, high-pressure stratum early warning, salt dome forward detection, target layer retrieval after fault missing, and the like. Regardless of the reservoir geology and its application, the purpose of this technique is to describe and clarify the geological formations and fluid distribution around the well, making up for the spatial scale gap between the conventional logging detection range and seismic resolution.
The detection depth of the current commercial underground electromagnetic far-detection instrument is up to 5 meters, which is called as 5 meters or the first generation far-detection instrument for short, 10 years ago, and the detection depth of the instrument developed in recent years is up to 30 meters, which is called as 30 meters or the second generation far-detection instrument for short. Service companies have also implemented second generation remote instrumentation ideally up to 50 to 60 meters of reach capability. These instruments have the characteristic that for remote detection they are made longer and longer, their length being substantially proportional to the depth of detection, which brings about a lot of inconveniences in terms of instrument manufacture, field application, data interpretation, service costs, etc. Another feature is that these instruments are electromagnetic field methods that operate in the frequency domain.
Over the past 20 years, many attempts have been made by various large oil companies and service companies in the area of remote exploration and drill bit forward-looking. These applications may be in horizontal wells, but also in vertical and directional wells.
In a horizontal well, the method mainly has geological guiding, ensures that a well hole is driven into a designed position, and keeps an optimized distance from a cover layer or an oil-water interface, and the like. Remote exploration is also used to optimize well trajectory for ease of post-drilling completion and production. In the horizontal well, the remote detection is used for searching a carbonate reservoir with gaps in a salt layer, finding a river channel sand lens body and finding a crack type gap reservoir, and the phenomenon that the reservoir is driven into a water cone body or is far away from a water layer is avoided.
Remote exploration has also found many applications in vertical or directional wells, such as seeing or looking through the salt or gypsum layers ahead and the distance to such layers, predicting the high pressure layers ahead to ensure drilling safety, defining the profile of nearby salt domes, etc. Also in vertical wells, it is desirable to detect remotely changes that provide lateral dephasing, detect remote oil-water boundaries in the wellbore, delineate unconnected reservoir spaces, and discover the accumulation of lost-oil gas by conventional methods.
In the production of multiple-recovery water injection in an oil field, remote detection and foresight can help to observe the water-driving or gas-driving front edge, the change of an oil-water interface, the formation of a gas cone and a water cone and the like. Several common distance detection and forward looking applications, such as omitting pilot wells by forward looking, anticipating pinch-out of the formation with forward looking, far detection to aid in driving into adjacent channel sand, and far vision to provide more accurate distance to the cap layer and to the oil-water interface.
The current commercial electromagnetic remote detection instrument for underground use in the market is mainly the first generation electromagnetic remote detection or '5 meter' instrument which is launched more than 10 years ago and the second generation electromagnetic remote detection instrument which is launched by '30 meter' in the recent years. Although service companies have established second generation electromagnetic distance-detecting instruments as far as 50 to 60 meters in an ideal case, for convenience, the second generation electromagnetic distance-detecting instrument is referred to herein collectively as "30 meters". Tables 1 and 2 list the comparison of the parameters and indexes of the electromagnetic far detection instrument in the foreign frequency domain well.
Table 1: some basic parameters of the "5 meter" instrument.
Figure BDA0002436193340000021
Table 2: some basic parameters of the "30 m" instrument
Figure BDA0002436193340000022
These instruments have the characteristic that, in order to achieve electromagnetic far detection, they make the instruments longer and longer, their length being substantially proportional to the depth of detection, which brings about a lot of inconveniences in terms of instrument manufacture, field application, data interpretation, service costs, etc. For example, a 30 meter telemetric setup requires that the distance between the transmit coil and the receive coil be around 30 meters or nearly 30 meters.
In order to see the far earth formation, it is necessary to see all the formations between near and far, and therefore the above-mentioned instrument requires, in addition to the longer transmitting and receiving coil pitches, other coil pitch combinations, such as short and medium transmitting and receiving coil pitches, which increases the complexity of the instrument structure and the manufacturing costs.
Disclosure of Invention
The invention provides an underground time domain electromagnetic multi-component far detection instrument for solving the technical problems, which can realize the time domain electromagnetic measurement in the underground far detection application, namely the instrument can adopt a shorter time domain electromagnetic multi-component far detection instrument to achieve the far detection which can be realized by a longer frequency domain electromagnetic induction instrument, thereby reducing the manufacturing cost of the detection instrument and simplifying the flow of underground operation.
One of the technical schemes adopted by the invention is as follows: a downhole time domain electromagnetic multicomponent remote detection instrument, comprising: the high-strength nonmagnetic stainless steel or alloy or composite material shell, and a three-component time domain electromagnetic transmitting module, a multi-stage array type multi-component time domain electromagnetic signal receiving module, a three-component optical fiber inertial navigation positioning and orienting module, an analog-to-digital conversion module and a memory which are arranged in the shell; the multi-stage array type multi-component time domain electromagnetic signal receiving module comprises: the device comprises a multilevel array type three-component time domain magnetic field signal acquisition unit and a multilevel array type single-component time domain electric field signal acquisition unit; the three-component optical fiber inertial navigation positioning and orienting module is arranged in the middle of the instrument and is used for acquiring the real-time azimuth, moving speed, position and inclination angle of the instrument;
the three-component time domain electromagnetic signal transmitting module is used for generating a three-component excitation magnetic field, the multistage array type three-component time domain magnetic field signal collecting unit is used for receiving three-component time domain magnetic field signals, and the multistage array type single-component time domain electric field signal collecting unit is used for collecting single-component time domain electric field signals; the analog-to-digital conversion module converts the three-component time domain magnetic field signal and the single-component time domain electric field signal into digital signals and stores the digital signals into a memory; the memory also comprises real-time azimuth, moving speed, position and inclination angle data of the instrument collected by the three-component optical fiber inertial navigation positioning and orientation module.
The photoelectric conversion module is arranged in the shell and used for converting digital signals output by the analog-to-digital converter into optical signals so as to transmit time domain electromagnetic data acquired by the underground instrument and real-time attitude data of the instrument to a computer in an instrument vehicle at a wellhead at a high speed by using optical fibers in the photoelectric composite cable.
The three-component time domain electromagnetic signal transmitting module is a three-component time domain electromagnetic transmitting coil of a time domain electromagnetic multi-component far detecting instrument. The three-component time domain electromagnetic transmitting coil of the time domain electromagnetic multi-component far detection instrument is formed by 6 coils which are opposite pairwise to form a mutually orthogonal transmitting coil system.
The multi-stage array type three-component time domain magnetic field signal acquisition unit is a multi-stage three-component magnetic field receiving coil of a time domain electromagnetic multi-component far detection instrument. Each stage of three-component magnetic field receiving coil of the time domain electromagnetic multi-component far detection instrument is formed by 6 coils which are opposite to each other in pairs to form a mutually orthogonal receiving coil system.
The multi-stage array type time domain electric field signal acquisition unit is a pair of time domain electric field receiving unpolarized electrodes which are component along the extension direction of the instrument, and each pair of the unpolarized electrodes is arranged at two ends of each three-component time domain magnetic field receiving coil.
The three-component fiber inertial navigation positioning and orienting module is one of an interference type fiber gyroscope, a resonance type fiber gyroscope, a stimulated Brillouin scattering light fiber gyroscope, a fiber gyroscope strapdown inertial navigation system, a fiber grating strapdown inertial navigation system, a fiber gyroscope and an inertial navigation module combined by a micro-mechanical gyroscope.
The three-component optical fiber inertial navigation positioning and orienting module is arranged between the three-component transmitting coil and the three-component magnetic field receiving coil.
The device also comprises a time service module which is used for carrying out time service on the real-time position, moving speed, position and inclination angle data of the instrument acquired by the three-component optical fiber inertial navigation positioning and orienting module and carrying out time service on the multi-component time domain electromagnetic data acquired by the underground time domain electromagnetic multi-component far detection instrument while drilling. The multi-component time domain electromagnetic data herein includes: the multi-stage array type three-component time domain magnetic field signal acquisition unit receives three-component time domain magnetic field signals and the multi-stage array type single-component time domain electric field signal acquisition unit acquires single-component time domain electric field signals.
A downhole time domain electromagnetic multi-component far detection system comprises the downhole time domain electromagnetic multi-component far detection instrument and a ground control and data acquisition processing subsystem, wherein the downhole time domain electromagnetic multi-component far detection instrument is connected with the ground control and data acquisition processing subsystem through an armored photoelectric composite cable so as to transmit time domain electromagnetic data acquired by the downhole instrument and real-time attitude data of the instrument to a computer in an instrument vehicle of a wellhead at a high speed by optical fibers in the photoelectric composite cable.
The second technical scheme adopted by the invention is as follows: time domain electromagnetic signal transmitting circuit of a downhole time domain electromagnetic multi-component remote detection instrument, comprising: the device comprises an alternating current/direct current power supply module, an active clamping voltage source module, a power inversion module, a digital logic control module, a driving module, a transmitting coil and a current waveform high-precision detection and recording module;
the alternating current/direct current power supply module is connected with the power inverter module and is used for converting an externally input alternating current power supply into a direct current power supply;
the power inversion module consists of 4 MOSFET power switches, the transmitting coil is connected with the 4 MOSFET power switches, the digital logic control module is used for generating a time sequence logic signal, and the drive module is used for controlling the on and off of the MOSFET power switches so as to generate a pulse current waveform;
the current waveform high-precision detection and recording module is connected with the transmitting coil and is used for detecting actual transmitting current in real time and recording the value of the transmitting current and the change of the waveform;
the active clamping voltage source module is used for providing stable high voltage during the rising edge and the falling edge of high-power current.
The direct current power supply comprises an AC-DC low-voltage high-power supply and an AC/DC high-voltage clamping power supply, the AC-DC low-voltage high-power supply provides required energy for transmitting current, and the AC/DC high-voltage clamping power supply acts on the active clamping voltage source module.
The active clamp voltage source module includes: the low-voltage direct-current power supply circuit comprises a low-voltage direct-current power supply circuit, a rising edge clamping circuit, a MOSFET full-bridge inverter circuit, a falling edge clamping circuit, a damping absorption circuit and a transmitting load circuit; the low-voltage direct-current power supply circuit, the rising edge clamping circuit, the MOSFET full-bridge inverter circuit and the falling edge clamping circuit are sequentially connected in series; the MOSFET full-bridge inverter circuit, the damping absorption circuit and the emission load circuit are connected in parallel;
the low-voltage direct-current source circuit comprises a resistor R1, a resistor R2, a resistor R3, a flat top section low-voltage source E1 and a capacitor C1, wherein a first end of the resistor R1 is connected with a first end of the resistor R2, a second end of the resistor R2 is connected with a first end of a resistor R3, a second end of the resistor R3 is grounded, a second end of the resistor R1 is connected with a first end of the flat top section low-voltage source E1, a second end of the flat top section low-voltage source E1 is grounded, a second end of the resistor R1 is also connected with a first end of the capacitor C1, and a second end of the capacitor;
the rising edge clamp circuit includes: the circuit comprises a clamp control switch Q5, a rising edge high-voltage clamp source E2, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, an AND gate, an OR gate, an operational amplifier CP1, a resistor R5, a diode D8 and a diode D9; the clamp control switch Q5 is a MOSFET, the drain of the clamp control switch Q5 is connected to the first end of a rising edge high-voltage clamp source E2, the second end of the rising edge high-voltage clamp source E2 is grounded, the source of the clamp control switch Q5 is connected to the cathode of a diode D8, the anode of a diode D8 is connected to the second end of a first resistor R1, the gate of the clamp control switch Q5 is connected to the output end of an and gate, the first input end of the and gate is connected to the output end of an operational amplifier, the second input end of the and gate is connected to the output end of an or gate, the first input end of the or gate is connected to a control signal S1, and the second input end of the or; the positive electrode of the operational amplifier CP1 is connected with the first end of a third resistor R3, the negative electrode of the operational amplifier CP1 is connected with an AC-DC low-voltage high-power supply, the negative electrode of the operational amplifier CP1 is grounded through a resistor R5, the positive electrode of the diode D9 is connected with the source electrode of a clamping control switch Q5, the negative electrode of the diode D9 is connected with an AC-DC low-voltage high-power supply, the positive electrode of the diode D10 is connected with an AC-DC low-voltage high-power supply, the first end of the E2 is further connected with a capacitor C2, the second end of the capacitor C2 is connected with the first end of a capacitor C4, the second end of the capacitor C4 is grounded, the first end of the capacitor C2 is further connected with the first end of a capacitor C3;
the MOSFET full-bridge inverter circuit comprises a power switch Q1, a power switch Q2, a power switch Q3, a power switch Q4 and a diode D10, wherein the power switch Q1, the power switch Q2, the power switch Q3 and the power switch Q4 are MOSFETs, the drain of the power switch Q1 is connected with the anode of a diode D10, the cathode of a diode D10 is connected with the drain of a power switch Q2, the grid of the power switch Q1 is connected with a control signal S1, the source of the power switch Q1 is connected with the drain of a power switch Q3, the grid of the power switch Q3 is connected with a control signal S2, the source of the power switch Q2 is grounded, the grid of the power switch Q2 is connected with a control signal S2, the source of the power switch Q2 is connected with the drain of the power switch Q2, and the source of the power switch Q;
the falling edge clamp circuit includes: a resistor R4, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a falling edge high voltage clamping source E3 and a diode D11; the first end of the resistor R4 is connected with the cathode of the diode D10, the second end of the resistor R4 is grounded, the first end of the ground resistor R4 is further connected with the first end of the capacitor C6, the second end of the capacitor C6 is connected with the first end of the capacitor C8, the second end of the capacitor C8 is grounded, the first end of the capacitor C6 is further connected with the first end of the capacitor C7, the second end of the capacitor C7 is connected with the first end of the capacitor C9, the second end of the capacitor C9 is grounded, the first end of the capacitor C7 is further connected with the cathode of the diode D11, the anode of the diode D11 is connected with the first end of the falling edge high-voltage clamping source E3;
the damping absorption circuit comprises a power switch Q6, a power switch Q7 and a resistor R6, wherein the drain of the power switch Q6 is connected with the source of the power switch Q1, the grid of the power switch Q6 is suspended, the source of the power switch Q6 is connected with the first end of the resistor R6, the second end of the resistor R6 is connected with the source of the power switch Q7, the grid of the power switch Q7 is suspended, and the drain of the power switch Q7 is connected with the source of the power switch Q2;
the transmitting load circuit comprises an inductor L and a resistor R, wherein the first end of the inductor L is connected with the source electrode of the power switch Q1, the second end of the inductor L is connected with the first end of the resistor R, and the second end of the resistor R is connected with the source electrode of the power switch Q2.
The invention has the beneficial effects that: the downhole time domain electromagnetic multi-component far detection instrument provided by the invention realizes the time domain electromagnetic measurement in downhole far detection application, so that the long detection which can be realized only by adopting a shorter time domain electromagnetic multi-component far detection instrument and a longer frequency domain instrument can be realized, the manufacturing cost of the downhole far detection instrument is greatly reduced, and the process of downhole operation is simplified.
Drawings
FIG. 1 is a schematic diagram of a downhole time domain electromagnetic multicomponent remote sensing instrument according to the present invention;
FIG. 2 is a functional schematic diagram of a downhole time domain electromagnetic multicomponent remote sensing instrument system of the present invention;
FIG. 3 is a block diagram of the overall circuit design of the downhole time domain electromagnetic multicomponent remote sensing instrument system of the present invention;
FIG. 4 is a three-dimensional time domain electromagnetic data processing method and flowchart of the present invention acquired by a downhole time domain electromagnetic multicomponent remote sensing instrument;
FIG. 5 is a block diagram of the overall design of a downhole time domain electromagnetic pulse transmitter of the downhole time domain electromagnetic multi-component remote sensing instrument of the present invention;
FIG. 6 is a schematic diagram of a fast-edge constant-voltage dual-clamping schematic diagram of a downhole time domain electromagnetic multi-component remote detection instrument of the present invention;
FIG. 7 is a circuit topology diagram of a constant voltage dual-clamp transmitter of the downhole time domain electromagnetic multicomponent remote sensing instrument transmitter of the present invention;
FIG. 8 is a functional block diagram of a data acquisition board system of a data receiving subsystem of the downhole time domain electromagnetic multicomponent remote sensing instrument of the present invention;
FIG. 9 is a schematic diagram of the structure of three-component time domain electromagnetic transmit and three-component magnetic field receive coils in a wireline logging tool of the downhole time domain electromagnetic multi-component remote detection system of the present invention;
FIG. 10 is a schematic block diagram of a downhole time domain electromagnetic multicomponent remote sensing instrument and surface control excitation and data reception system of the present invention.
Description of reference numerals: 1 is a casing of a downhole time domain electromagnetic multi-component remote detection instrument; 3 is a three-component optical fiber inertial navigation positioning and orienting module; 4 is a high-temperature resistant high-precision constant-temperature crystal oscillator or atomic clock chip; 5 is an armored photoelectric composite cable connected with the underground multi-component instrument; 6, a 32-bit analog-to-digital conversion circuit and a memory which are connected with the three-component optical fiber inertial navigation sensor device are provided; 12 is a three-component electromagnetic transmitting coil of the array time domain electromagnetic multi-component far detection instrument; 14 is a multistage three-component electromagnetic receiving coil of an array time domain electromagnetic multi-component far detection instrument; 15 is a non-polarized electrode for receiving vertical electric field components of the array time domain electromagnetic multi-component far detection instrument; 16 is a ground large current source emission control excitation unit; 17 is a ground multichannel control and data receiving unit; 31 is a photoelectric conversion module; 32 is a multi-channel 32-bit analog-to-digital conversion circuit and a memory; 70 is the casing of the logging-while-drilling instrument; 71 is a sensor fixing bracket in the logging-while-drilling instrument; 72. a drilling mud channel inside the logging-while-drilling instrument; 73 is a roller bit of the logging while drilling instrument; 74 is a vertical magnetic field component transmitting coil; 75 is a horizontal magnetic field component transmitting coil; 76 is a horizontal magnetic field component transmitting coil; 77 is a vertical magnetic field component receiving coil; 78 horizontal magnetic field component receiving coils; and 79 is a horizontal magnetic field component receiving coil.
Detailed Description
In order to facilitate the understanding of the technical contents of the present invention by those skilled in the art, the present invention will be further explained with reference to fig. 1 to 10.
The principle of time domain electromagnetic method is that a periodic pulse current is fed into a transmitting coil, and the underground pulse current generates a primary field in the space around the underground pulse current. When a good conductor (metal ore) or a high-resistance body (oil or natural gas) exists underground, eddy currents are induced in the good conductor due to the electromagnetic induction principle, the high resistance body repels the current of a primary field, and the eddy currents induced in the good conductor or the current of the primary field repelled by the high resistance body can generate a secondary field in the surrounding space. When the primary field pulse magnetic field is cut off, the induced current in the conductor or the current of the primary field repelled by the high-resistance body does not disappear immediately, but the transition process of gradual diffusion, attenuation and disappearance is performed according to an exponential law. Thus, the space around the conductor forms a decaying secondary magnetic field, which can be described by the term smoke ring effect. This decaying and diffusing secondary magnetic field is the temporal characteristic of the secondary magnetic field. Studying the temporal behavior of the secondary field is one of the main tasks of time domain electromagnetic methods.
In wireline logging applications, for electromagnetic long-reach and look-ahead, time-domain electromagnetic methods can be used to image conductivity distributions at relatively large distances from the borehole, according to the theory of time-domain electromagnetic methods, to facilitate optimal well placement in hydrocarbon reservoirs. According to the theory of the time domain electromagnetic method, when the time t is 0 (before one field outage), a direct current magnetic field is built up in the stratum around the emission source of the time domain electromagnetic instrument, and transient induction voltage caused by sudden cut-off of the source current when the time t is 0 (at one field outage) is recorded. Experiments have demonstrated that time domain electromagnetic measurements can be used to define time dependent conductivity, as well as time dependent apparent dip and azimuth angles. Can be used to determine the presence and location of conductive or high-resistance anomalies in a uniform background and can therefore be used to obtain an image of the conductivity distribution of the rock or reservoir surrounding the borehole.
The far detection instrument of time domain electromagnetism multicomponent in pit of this embodiment includes: the device comprises a high-strength nonmagnetic stainless steel or alloy or composite material shell 1, a time domain electromagnetic signal transmitting module 12, a multi-stage array time domain magnetic field signal collecting unit 14, a multi-stage array time domain electric field signal collecting unit 15, a three-component optical fiber inertial navigation positioning and orienting module 3, an analog-to-digital conversion module and a memory 6, wherein the time domain electromagnetic signal transmitting module 12, the multi-stage array time domain magnetic field signal collecting unit, the three-component optical fiber inertial navigation positioning and orienting; the three-component optical fiber inertial navigation positioning and orienting module 3 is arranged between the transmitting module 12 and the magnetic field signal acquisition unit 14 and is used for acquiring real-time azimuth, moving speed, position and inclination angle data of an instrument;
the three-component time domain electromagnetic signal transmitting module 12 is used for generating a three-component excitation magnetic field, the multi-stage array three-component time domain magnetic field signal collecting unit 14 is used for receiving three-component time domain magnetic field signals, and the multi-stage array single-component time domain electric field signal collecting unit 15 is used for collecting single-component time domain electric field signals; the analog-to-digital conversion module converts the three-component time domain magnetic field signal and the single-component time domain electric field signal into digital signals and stores the digital signals into a memory; the memory also comprises data for storing the real-time azimuth, moving speed, position and inclination angle of the instrument collected by the three-component optical fiber inertial navigation positioning and orientation module.
The photoelectric conversion module is arranged in the shell and used for converting digital signals output by the analog-to-digital converter into optical signals so as to transmit time domain electromagnetic data acquired by the underground instrument and real-time attitude data of the instrument to a computer in an instrument vehicle at a wellhead at a high speed by using optical fibers in the photoelectric composite cable.
In this embodiment, the three-component time domain electromagnetic signal transmitting module 12 is a three-component magnetic field transmitting coil of a time domain electromagnetic multi-component far detection instrument, 6 coils are opposite in pairs to form a mutually orthogonal transmitting coil system, the center of the mutually orthogonal transmitting coil system formed by opposite in pairs of 6 coils is hollow, so that a power line and a signal line inside the instrument can conveniently pass through the center of the transmitting coil system and be connected to an armored photoelectric composite cable at the top end of the instrument.
The multistage array type three-component time domain magnetic field signal acquisition unit 14 in the embodiment is a multistage three-component magnetic field receiving coil of an array type time domain multi-component electromagnetic remote detection instrument, 6 coils of each stage are opposite in pairs to form a mutually orthogonal receiving coil system, the centers of the mutually orthogonal receiving coil systems formed by opposite 6 coils in pairs are hollow, and a power line and a signal line in the instrument conveniently penetrate through the centers of the receiving coil systems and are connected to an armored photoelectric composite cable at the top end of the instrument.
In this embodiment, the multi-stage array single-component time domain electric field signal collecting unit 15 is an unpolarized electrode pair for measuring an electric field distributed along the extending direction of the instrument, and each pair of unpolarized electrode pairs is installed at two ends of each three-component time domain magnetic field receiving coil.
The three-component optical fiber inertial navigation directional positioning system is fixed beside the three-component magnetic field sensor, and when the sensor in the instrument works, the three-component optical fiber inertial navigation directional positioning system records information such as the position, the moving speed, the direction, the posture and the like of the three-component magnetic field sensor in real time.
Fig. 1 is a schematic structural diagram of a downhole time domain electromagnetic multi-component far detection instrument of the present invention, which includes: the device comprises a casing 1 for receiving a time domain electromagnetic multi-component far detection instrument by an underground three-component transmitting multi-component array, a three-component electromagnetic transmitting coil 12 of the time domain electromagnetic multi-component far detection instrument, a three-component optical fiber inertial navigation positioning and orienting module 3, a three-component time domain magnetic field receiving coil 14 of the time domain electromagnetic multi-component far detection instrument, a non-polarized electrode 15 for receiving a single component time domain electric field signal of the time domain electromagnetic multi-component far detection instrument along the extension direction of the instrument and an armored photoelectric composite cable 5. The three-component optical fiber inertial navigation positioning and orienting module 3 is installed between a three-component electromagnetic transmitting coil 12 and an array three-component magnetic field receiving coil 14, is used for measuring and recording the actual position and position coordinate information of all measuring points of the underground three-component time domain electromagnetic transmitting multi-component time domain electromagnetic array receiving instrument in the operation process in real time, and uploads the underground time domain electromagnetic multi-component data measured by the three-component transmitting multi-component array receiving time domain electromagnetic multi-component far detecting instrument to a computer in a well head logging instrument vehicle for storage in real time through an armored photoelectric composite cable 5, so that the subsequent data processing is facilitated.
Aiming at the underground time domain electromagnetic multi-component far detection instrument while drilling, a high-temperature-resistant high-precision constant-temperature crystal oscillator or an atomic clock chip is adopted to time the time three-component inter-domain magnetic field data, the single-component time domain electric field data and the three-component optical fiber inertial navigation data which are measured in real time, so that the continuous data acquisition of the underground time domain electromagnetic multi-component far detection instrument while drilling is realized.
The communication problem between the underground detection instrument and the ground control and data acquisition subsystem can be divided into two situations, namely, firstly, the underground detection instrument can directly carry out real-time high-speed communication with the ground control and data acquisition subsystem through the armored photoelectric composite cable 5; the other is that the data storage module in the underground while drilling instrument records and stores the acquired multi-component time domain electromagnetic data and the real-time position, speed and attitude data of the three-component magnetic field sensor, and the stored data is led into the ground control and data acquisition subsystem after the instrument is out of the well; to ensure the real-time data acquisition problem of the second case; the invention adds a time service module into the instrument, and the specific working process is as follows:
the three-component time domain controllable electromagnetic source transmitting sensor and the four-component time domain electromagnetic receiving sensor of the underground time domain electromagnetic multi-component far detection instrument are used for storing the actually measured three-component time domain electromagnetic transmitting data and four-component time domain electromagnetic receiving data in a memory after being timed by a timer; the three-component optical fiber inertial navigation positioning and orienting module is used for storing real-time position, speed and attitude information of a three-component magnetic field sensor which is actually measured in a memory after being timed by a timer, and transmitting data in the memory to a ground control and data acquisition subsystem after an underground time domain electromagnetic multi-component far detection instrument while drilling is taken out from the underground. The communication connection is specifically connected through an armored photoelectric composite cable.
The second case further comprises: the photoelectric conversion circuit specifically comprises the working processes of: a multi-component sensor of the underground time domain electromagnetic multi-component far detection instrument is connected with the input end of a 32-bit analog-to-digital conversion circuit, a three-component optical fiber inertial navigation positioning and orientation module is connected with the input end of the 32-bit analog-to-digital conversion circuit through a photoelectric conversion circuit, and the output end of the 32-bit analog-to-digital conversion circuit is connected with a memory.
A three-component time domain electromagnetic signal transmitting unit of the underground time domain electromagnetic multi-component far detection instrument is a three-component induction coil type transducer or a three-component electromagnetic transmitting sensor. The multi-level array time domain magnetic field signal sensor is a three-component induction coil type magnetic field sensor, or a three-component fluxgate type magnetic field sensor, or a three-component superconducting magnetic field sensor, or a three-component cold atom magnetic field sensor, or a three-component optical fiber magnetic field sensor.
The underground multistage array type single-component time domain electric field signal acquisition unit 15 of the underground time domain electromagnetic multi-component far detection instrument is an unpolarized electrode pair for measuring an electric field distributed along the extension direction of the instrument, and each pair of unpolarized electrode pairs is arranged at two ends of each three-component time domain magnetic field receiving coil.
The three-component optical fiber inertial navigation positioning and orienting module of the underground time domain electromagnetic multi-component far detection instrument is an inertial navigation module formed by combining an interference type optical fiber gyroscope, a resonant type optical fiber gyroscope, a stimulated Brillouin scattering optical fiber gyroscope, an optical fiber gyroscope strapdown inertial navigation system, an optical fiber grating strapdown inertial navigation system, an optical fiber gyroscope and a micro-mechanical gyroscope.
As shown in fig. 2, a schematic functional diagram of a downhole time domain electromagnetic multi-component far detection instrument is divided into functions, and mainly includes: the array type three-component receiving coil comprises an electronic unit, a three-component transmitting coil and an array type three-component receiving coil, wherein the electronic unit comprises a transmitter circuit and a receiver circuit; the whole circuit design block diagram of the underground time domain electromagnetic multi-component far detection instrument system is shown in fig. 3, and a specific transmitter circuit is connected with a three-component transmitting coil through switch control and transmits in a time-sharing mode. The array receiving coil and the receiving electrode are connected with the multi-channel receiver, and three-component time domain magnetic field data and single-component time domain electric field data are collected and stored in real time. The array receiver simultaneously collects three-component transmitting current signals in real time and stores the three-component transmitting current signals.
FIG. 4 is a three-dimensional time domain electromagnetic data processing method and flow chart acquired by a downhole time domain electromagnetic multi-component far detection instrument. The data processing method of the data detected by the invention is the prior art, and for example, the following processing flows can be adopted, including:
1. according to a well track curve, firstly converting a measured depth value (MD) of the downhole instrument at each measuring point position into a vertical depth value (TD) from a well mouth to a well bottom;
2. rotating multi-component time domain electromagnetic data according to the inclination angle, azimuth angle and inclination of a multi-component sensor of the underground time domain electromagnetic multi-component far detection instrument measured by a three-component optical fiber inertial navigation positioning and orienting module;
3. extracting three-component resistivity data of the rock or the stratum related to the electromagnetic property according to the multi-component time domain electromagnetic data subjected to the rotation processing in the step 2;
4. performing inversion imaging according to the three-component resistivity data extracted in the step 3, and acquiring a distribution rule of electrical parameters (resistivity and polarizability (induced polarization parameters)) of the rock or the stratum within a certain distance range of the measuring point position;
5. simulating anisotropic high-precision numerical values by adopting a time domain transient electromagnetic three-dimensional correction algorithm with strong adaptability;
6. in the iterative algorithm calculation process, a matrix-free method is used for calculating a matrix vector product, and the parallelization of the algorithm is realized by utilizing a distributed grid partitioning technology, wherein the parallelization algorithm reaches or approaches to a linear acceleration ratio;
7. by utilizing a rapid inversion and imaging technology, through parallel calculation and rapid solving of a Jacobian matrix, the inversion and imaging speed is accelerated, and the electrical parameter distribution characteristics and the law of the underground medium from a borehole to a remote place are calculated;
8. according to other geology, structure, lithology, reservoir and electrical parameter distribution characteristics and rules thereof, the enrichment degree (oil-gas saturation or mineral resource grade) of oil gas or mineral resources from a wellhead to a remote range is comprehensively explained, and the aim of detecting geological targets far away from a borehole by using a downhole time domain electromagnetic multi-component far detection instrument is fulfilled.
The three-dimensional time domain electromagnetic data collected by the detecting instrument of the present invention can be processed by those skilled in the art with reference to the processing flow shown in fig. 4, and the detailed description is omitted here since the specific data processing method is not the focus of the present invention.
FIG. 5 is a block diagram of the overall electrical circuitry of a downhole three-component time domain electromagnetic pulse transmitter of a downhole time domain electromagnetic multi-component far detection instrument transmitting subsystem. The method mainly comprises the following steps: the device comprises an alternating current/direct current power supply module, an active clamping voltage source module, a power inversion module, a driving module, a digital logic control module, a damping circuit, a transmitting coil and a current waveform high-precision detection and recording module. The transmitting system adopts a single-phase alternating current generator to supply power through a plurality of kilometers of photoelectric composite cables on the ground, obtains direct current supply voltage through an alternating current/direct current conversion device, and obtains direct current clamping high voltage through the alternating current/direct current conversion device. The transmitter control core module based on the FPGA controls the three-phase alternating current/direct current conversion circuit by utilizing a PWM (pulse-width modulation) technology, accurately controls the output voltage and the output current of the power conversion circuit, and finally realizes that the MOSFET (metal-oxide-semiconductor field effect transistor) power switch circuit of the transmitter outputs the load of the transmitter according to the constant current of a preset value.
FIG. 6 is a schematic diagram of a fast edge constant voltage dual clamp position of a downhole three-component time domain electromagnetic pulse transmitter of a downhole time domain electromagnetic multi-component far detection instrument. The multi-turn small coil is an inductive load, the current pulse excites an electromagnetic signal through the multi-turn small coil, and the design of the load coil must be matched with a transmitter circuit. Meanwhile, the actual emission current is detected in real time, and the change of the emission current waveform is accurately recorded. The safety protection and fault alarm circuit can monitor the working state of the transmitter in real time, and once the phenomena of overlarge current, overhigh voltage, overheating temperature and the like occur, the safety protection and fault alarm circuit can immediately alarm and cut off a power supply, so that the safe and stable work of a transmitter system is ensured.
A circuit topological diagram of a constant-voltage double-clamping transmitter of a downhole time domain electromagnetic multi-component far detection instrument transmitter is shown in FIG. 7. The direct current power supply comprises an AC-DC low-voltage high-power supply and an AC/DC high-voltage clamping power supply, and the two power supplies are independent and provide energy for the transmitter system. The active clamping voltage source consists of a high-voltage direct-current constant-voltage source controlled by a power switch, and is used for providing stable high voltage for a transmitting system during the rising edge and the falling edge of transmitting current, so that the transmitting current linearly and rapidly rises and simultaneously linearly falls. The full-bridge inverter circuit is composed of 4 high-power MOSFET power switches, and pulse current waveforms are generated by controlling the on and off of the power switches.
The digital logic controller FPGA is a control core of the transmitter, and generates a time sequence logic signal under the action of a synchronous clock, so that the on and off of the power switch are controlled, the signals between transmitting and receiving are synchronous, and the parameters are detected.
FIG. 8 is a functional block diagram of a data acquisition board system of a data receiving subsystem of a downhole time domain electromagnetic multi-component far detection instrument. The data acquisition subsystem is composed of an analog signal conditioning module, a data acquisition module and a data storage and transmission module, and a structural block diagram of the system is shown in fig. 8. The data acquisition subsystem conditions the analog signal that magnetic field sensor subsystem triaxial magnetic field sensor output makes it satisfy ADC input signal scope, carries out digital quantization through 24 bit ADC, and the data after the quantization are stored in on-board buffer memory and are sent to the host computer through CAN bus interface.
In order to improve the detection sensitivity of the system, the gain of the magnetic field sensor is larger, the amplitude of an output signal of the magnetic field sensor is +/-12V, the maximum unsaturated voltage of an acquisition circuit ADC is +/-2.5V, and in order to avoid the saturation of the ADC when the input signal is too large, the default gain of a preamplifier is designed to be 1/5 by the analog signal conditioning module, so that the amplitude of the signal is +/-2.4V, and the requirement of matching with the input voltage of the ADC is met. In order to suppress common-mode signal interference, the preamplifier adopts a differential input mode and a differential output mode. The analog signal conditioning module mainly comprises a low-pass filter composed of operational amplifiers THS4521-HT and RC, the THS4521-HT working temperature can reach 210 ℃, the working current of each channel is 1.4mA, and the design requirements of high temperature and low power consumption of the system can be met.
The data acquisition module design comprises an analog-to-digital conversion circuit, a voltage reference circuit and a data transmission interface design. The system main control selects a high-performance high-temperature DSP processor SM320F28335-HT of Texas Instruments (TI), the highest working temperature CAN reach 210 ℃ when the working frequency is 100MHz, and the main functions comprise controlling the ADC to collect data, controlling the data to be stored and read, analyzing a control command sent by the upper computer and returning the collected data to the upper computer through a CAN bus interface. The ADC adopts a Texas Instruments (TI) company high-temperature synchronous sampling 24-bit analog-to-digital converter ADS1278, the chip can support 8-channel synchronous sampling at most, a plurality of independent high-order chopper-stabilized modulators and FIR digital filters are integrated in the chip, and 4 working modes of high speed, high precision, low power consumption and low speed are supported; the sampling rate is up to 128 KSPS. Wherein, 3 receiving channels are used for receiving signals of the three-axis magnetic field sensor, 1 channel is used for acquiring temperature information, and the rest channels are used for acquiring state information. And the data output can select a frame synchronization or SPI serial interface to realize the connection with the DSP microcontroller.
Since the precision and stability of the reference voltage VREF have great influence on the precision and stability of ADS1278, the data acquisition module selects REF5025-HT and OPA2333-HT of TI company to form a reference voltage source of the system. REF5025-HT is a high-precision reference source with high temperature, low noise and extremely low drift, can provide a reference voltage of 2.5V, and has the maximum working temperature of 210 ℃. The OPA2333-HT is a high-temperature micro-power-consumption precision operational amplifier, the maximum working temperature can reach 210 ℃, two operational amplifiers are arranged in the OPA, one of the two operational amplifiers is used as a voltage follower, the input of the two operational amplifiers is a COM end of an ADS1278, and the input end of the two operational amplifiers is connected with a 0.1uF capacitor for reducing noise. The output is connected to the COM terminal of the basic differential input signal interface circuit for providing a reference voltage, and the other is used for providing a reference voltage for the ADS 1278.
In order to improve the data storage speed, the data storage and transmission module directly writes the sampled digital signals into a cache in a binary mode, and the conversion of a file system is not involved in the middle. As an industrial field bus technology which effectively supports distributed detection and real-time control, the CAN bus has the advantages of high reliability, high communication speed, long transmission distance, easy networking and the like, and CAN establish a good data communication system. The data storage and transmission module applies the CAN bus technology to a data transmission system of a ground well electromagnetic measurement system, and on the basis that parameters acquired by a ground well instrument are transmitted to the ground through a cable, all data acquisition and transmission nodes are connected to a ground CAN network to complete the sending of ground host commands and the uploading of data of the acquisition nodes, and the data storage and transmission module is used for command interaction and data transmission of a telemetering system and a data acquisition subsystem. The CAN transceiver selects 3.3V high-temperature SN65HVD333-HT with standby mode and loopback function of TI company, is in accordance with the application of controller LAN serial communication physical layer of ISO11898 standard, has signaling speed up to 1Mbps, and has cross line protection, overvoltage protection up to +/-36V, grounding failure protection, overheating (thermal shutdown) protection and common mode transient protection function of +/-100V.
FIG. 9 is a schematic diagram of the structure of three-component time domain electromagnetic transmit and three-component magnetic field receive coils (without roller cone bit 73) in a wireline logging tool of a downhole time domain electromagnetic multi-component remote detection system. The coil of the three-component time domain controllable electromagnetic source transmitting sensor is formed by 6 coils which are opposite in pairs to form a mutually orthogonal transmitting coil system, the center of the mutually orthogonal transmitting coil system formed by 6 coils which are opposite in pairs is hollow, so that a power line and a signal line in an instrument can conveniently penetrate through the center of the transmitting coil system and are connected to an armored photoelectric composite cable at the top end of the instrument. The coil of each three-component time domain magnetic field signal sensor is formed by 6 coils which are opposite in pairs to form a mutually orthogonal receiving coil system, the center of the mutually orthogonal receiving coil system formed by 6 coils which are opposite in pairs is hollow, so that a power line and a signal line in the instrument can conveniently penetrate through the center of the receiving coil system and are connected to an armored photoelectric composite cable at the top end of the instrument.
FIG. 9 is a schematic diagram of the structure of three-component time domain electromagnetic transmitting and three-component magnetic field receiving coils (including roller cone bit 73) in a LWD tool of a downhole time domain electromagnetic multi-component far detection system, including: the device comprises a logging-while-drilling instrument shell 70, a logging-while-drilling instrument inner sensor fixing support 71, a drilling mud channel 72 inside the logging-while-drilling instrument, a roller bit 73 of the logging-while-drilling instrument, a three-component optical fiber inertial navigation positioning and orienting module 3, a photoelectric conversion module 31 connected with a three-component optical fiber inertial navigation sensor device, a 32-bit analog-to-digital conversion circuit and a memory 6 connected with the photoelectric conversion module 31, a high-temperature-resistant high-precision constant-temperature crystal oscillator or chip-level atomic clock 9, a vertical magnetic field component transmitting coil 74, a first horizontal magnetic field component transmitting coil 75, a second horizontal magnetic field component transmitting coil 76, a vertical magnetic field component receiving coil 77, a first horizontal magnetic field component receiving coil 78 and a second horizontal magnetic field component receiving coil 79.
The three-component optical fiber inertial navigation positioning and orientation module 3 is arranged between three-component magnetic field component transmitting coils 74, 75 and 76 and three-component magnetic field receiving coils 77, 78 and 79 in a three-component while-drilling induction logging instrument, and the high-temperature-resistant high-precision constant-temperature crystal oscillator or chip-level atomic clock 4 is arranged below the three-component optical fiber inertial navigation positioning and orientation module 3. The three-component optical fiber inertial navigation positioning and orienting module 3 is used for measuring and recording the actual position and position coordinate information of all measuring points of the three-component while-drilling induction logging instrument in the drilling operation process in real time, a 32-bit analog-to-digital conversion circuit connected with the three-component optical fiber inertial navigation sensor device and a memory 6 convert the real-time position, speed and attitude information of a multi-component sensor in the measured underground time domain electromagnetic multi-component far detection instrument into digital signals through the analog-to-digital conversion circuit and then store the digital signals in the memory, and the high-precision constant-temperature crystal oscillator or a chip-level atomic clock gives time to the recorded time domain electromagnetic data, the real-time position, speed and attitude information of the multi-component sensor.
After the underground time domain electromagnetic multi-component far detection instrument while drilling is taken out from a shaft, underground actually-measured multi-component time domain electromagnetic data and real-time position, speed and attitude information of a multi-component sensor stored in the underground time domain electromagnetic multi-component far detection instrument while drilling are transmitted to a ground control and data acquisition processing subsystem, so that subsequent data processing is facilitated.
FIG. 10 is a schematic block diagram of a downhole time domain electromagnetic multicomponent remote detection instrument and surface control excitation and data reception system of the present invention. The method comprises the following steps: the system comprises a three-component optical fiber inertial navigation positioning and orientation module 3, an armored photoelectric composite cable 5 connected with a downhole time domain electromagnetic multi-component far detection instrument, a three-component time domain electromagnetic transmitting coil 12 of the downhole time domain electromagnetic multi-component far detection instrument, an array three-component time domain electromagnetic receiving coil 14 of the downhole time domain electromagnetic multi-component far detection instrument, an array unpolarized electrode pair 15 for receiving electric field components of the downhole time domain electromagnetic multi-component far detection instrument along the extension direction of the instrument, a ground large current source control excitation unit 16, a ground multichannel control and data receiving unit 17, a photoelectric conversion module 31, a multichannel 32-bit analog-to-digital conversion circuit and a memory 32. The working principle is as follows: when the downhole time domain electromagnetic multi-component far detection instrument can start to transmit and collect data when the instrument goes down to the bottom of the well, the three-component optical fiber inertial navigation positioning and orientation module 3 arranged in the middle of the instrument synchronously starts to measure and record the real-time position, position and inclination angle of the downhole instrument at the moment and transmits the real-time position, position and inclination angle to the ground multi-channel control and data receiving unit 17 in real time. The ground large current source control excitation unit 16 starts to send preset excitation current to the three-component electromagnetic transmitting coil 12 of the downhole time domain electromagnetic multi-component far detection instrument through the photoelectric composite cable 5, so that the transmitting coil generates a three-component excitation magnetic field, meanwhile, the three-component electromagnetic receiving coil 14 of the downhole time domain electromagnetic multi-component far detection instrument starts to synchronously receive a three-component primary (excitation) magnetic field signal generated by the excitation current transmitted by the three-component transmitting coil, at the moment, the stratum generates secondary induced current under the three-component excitation magnetic field signal, and the secondary induced current generates a secondary induced magnetic field in the three-component magnetic field receiving coil. Meanwhile, the electric field component of the downhole time domain electromagnetic multi-component far detection instrument along the extension direction of the instrument receives a signal of a primary induced current field generated by measuring an excitation magnetic field emitted by a three-component transmitting coil by using a non-polarized electrode pair 15 and a signal of a secondary induced current field generated by the stratum under the three-component excitation magnetic field signal. The multi-component electromagnetic signals collected by the three-component magnetic field sensor (coil) and the electric field component sensor (non-polarized electrode pair) along the extension direction of the instrument are converted into digital signals through the multi-channel 32-bit analog-to-digital conversion circuit and the memory 32 and are synchronously stored in the memory, meanwhile, the converted digital signals are converted into optical signals through the photoelectric conversion module 31, and then the converted optical signals are transmitted to the multi-channel control and data receiving unit 17 on the ground through the photoelectric composite cable 5 for quality monitoring (QC) and storage so as to facilitate later processing.
The data collected by the downhole time domain electromagnetic multi-component far detection instrument can be three-component controllable source electric field data and three-component controllable source magnetic field data. Through data processing, three-component resistivity data, three-component polarizability data and the like of the underground formations can be calculated.
The high-temperature-resistant high-precision optical fiber inertial navigation device can be an interference type optical fiber gyroscope (I-FOG), a resonant type optical fiber gyroscope (R-FOG), a stimulated Brillouin scattering optical fiber gyroscope (B-FOG), an optical fiber gyroscope strapdown inertial navigation system, an optical fiber grating strapdown inertial navigation system, an inertial navigation system combining an optical fiber gyroscope and a micro-mechanical gyroscope and the like.
The working principle of the invention is as follows: and acquiring underground time domain electromagnetic multi-component data of each underground measuring point and acquiring inertial navigation data at the same measuring point position by using a high-precision optical fiber inertial navigation device. And then, the operator moves the underground time domain electromagnetic multi-component far detection instrument to the next pre-designed measuring point position for data acquisition operation until the data acquisition operation of all measuring points in the well is completed.
And rotating all the multi-component time domain electromagnetic data acquired underground one by using a method in the projection rotation processing step to ensure that the vertical component of the multi-component time domain electromagnetic data is vertical to the horizontal ground, the two horizontal components are changed into a horizontal component in the north-south direction, and the other horizontal component in the east-west direction. Or one horizontal component is parallel to the trend of the geologic body or the direction of the given cross section through the rotation processing, and the other horizontal component is perpendicular to the trend of the geologic body or the direction of the given cross section and is parallel to the ground.
And further processing the projected and rotated three-component controllable source electric field data, three-component controllable source magnetic field data, three-component resistivity data, three-component polarizability data and the like in the well through forward simulation, inversion calculation and other steps, and extracting the three-component resistivity data and the three-component polarizability data of the rock or the stratum related to the electromagnetic property.
And performing inversion imaging on the three-component resistivity data and the three-component polarizability data of each underground measuring point position to obtain the distribution rule of the electrical parameters (resistivity and polarizability) of the rock or the stratum within a certain distance range of the measuring point position.
According to the obtained distribution rule of the resistivity value and the polarizability value of the rock or the stratum, the explanation and evaluation of the distribution characteristics and rule of the geological structure, the oil gas-containing rock or the stratum or the high polarizability minerals in a certain range of the measuring point position are realized.
It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims (10)

1. Far detecting instrument of time domain electromagnetism multicomponent in pit, its characterized in that includes: the high-strength nonmagnetic stainless steel or alloy or composite material shell, and a three-component time domain electromagnetic transmitting module, a multi-stage array type multi-component time domain electromagnetic signal receiving module, a three-component optical fiber inertial navigation positioning and orienting module, an analog-to-digital conversion module and a memory which are arranged in the shell; the multi-stage array type multi-component time domain electromagnetic signal receiving module comprises: the device comprises a multilevel array type three-component time domain magnetic field signal acquisition unit and a multilevel array type single-component time domain electric field signal acquisition unit; the three-component optical fiber inertial navigation positioning and orienting module is arranged in the middle of the instrument and is used for acquiring the real-time azimuth, moving speed, position and inclination angle of the instrument;
the three-component time domain electromagnetic signal transmitting module is used for generating a three-component excitation magnetic field, the multistage array type three-component time domain magnetic field signal collecting unit is used for receiving three-component time domain magnetic field signals, and the multistage array type single-component time domain electric field signal collecting unit is used for collecting single-component time domain electric field signals; the analog-to-digital conversion module converts the three-component time domain magnetic field signal and the single-component time domain electric field signal into digital signals and stores the digital signals into a memory; the memory also comprises real-time azimuth, moving speed, position and inclination angle data of the instrument collected by the three-component optical fiber inertial navigation positioning and orientation module.
2. The downhole time domain electromagnetic multi-component far detection instrument according to claim 1, further comprising a time service module and a photoelectric conversion module installed in the housing, wherein the time service module is used for providing time service for the three-component optical fiber inertial navigation positioning and orienting module to acquire real-time azimuth, moving speed, position and inclination data of the instrument, and for providing time service for the three-component time domain magnetic field data and the single-component time domain electric field data; the photoelectric conversion module is used for converting the digital signal output by the analog-to-digital converter into an optical signal.
3. The downhole time domain electromagnetic multicomponent teledetection instrument of claim 1 or 2, wherein the three-component time domain electromagnetic signal transmitting module is a three-component time domain electromagnetic transmitting coil of the time domain electromagnetic multicomponent teledetection instrument; the three-component time domain electromagnetic transmitting coil of the time domain electromagnetic multi-component far detection instrument is formed by 6 coils which are opposite pairwise to form a mutually orthogonal transmitting coil system.
4. The downhole time domain electromagnetic multi-component far detection instrument according to claim 3, wherein the array type three-component time domain magnetic field signal acquisition unit is a multistage three-component magnetic field receiving coil; each stage of three-component magnetic field receiving coil is formed by 6 coils which are opposite to each other in pairs to form a mutually orthogonal receiving coil system.
5. The downhole time domain electromagnetic multi-component far detection instrument according to claim 1 or 2, wherein the multi-stage array type single-component time domain electric field signal acquisition unit is a pair of time domain electric field receiving unpolarized electrodes which are components along the extension direction of the instrument, and each pair of the unpolarized electrodes is installed at two ends of each three-component time domain magnetic field receiving coil.
6. A downhole time domain electromagnetic multi-component far detection instrument according to claim 1 or 2, wherein the three-component fiber optic inertial navigation positioning and orientation module is mounted between a three-component transmitting coil and a three-component magnetic field receiving coil. The three-component fiber inertial navigation positioning and orienting module is one of an interference type fiber gyroscope, a resonance type fiber gyroscope, a stimulated Brillouin scattering light fiber gyroscope, a fiber gyroscope strapdown inertial navigation system, a fiber grating strapdown inertial navigation system, a fiber gyroscope and an inertial navigation module combined by a micro-mechanical gyroscope.
7. A downhole time domain electromagnetic multicomponent teledetection instrument according to claim 1 or 2, further comprising a three-component time domain electromagnetic signal transmission circuit, the circuit comprising: the device comprises an alternating current/direct current power supply module, an active clamping voltage source module, a power inversion module, a digital logic control module, a driving module, a transmitting coil and a current waveform high-precision detection and recording module;
the alternating current/direct current power supply module is connected with the power inverter module and is used for converting an externally input alternating current power supply into a direct current power supply;
the power inversion module consists of 4 MOSFET power switches, the transmitting coil is connected with the 4 MOSFET power switches, the digital logic control module is used for generating a time sequence logic signal, and the drive module is used for controlling the on and off of the MOSFET power switches so as to generate a pulse current waveform;
the current waveform high-precision detection and recording module is connected with the transmitting coil and is used for detecting actual transmitting current in real time and recording the value of the transmitting current and the change of the waveform;
the active clamping voltage source module is used for providing stable high voltage during the rising edge and the falling edge of high-power current.
8. The downhole time domain electromagnetic multicomponent teledetection instrument of claim 7, wherein the direct current power supply comprises an AC-DC low voltage high power supply that provides the required energy for the transmit current and an AC/DC high voltage clamp supply that acts on the active clamp voltage supply module.
9. The downhole time domain electromagnetic multicomponent teledetection instrument of claim 8, wherein the active clamp voltage source module comprises: the low-voltage direct-current power supply circuit comprises a low-voltage direct-current power supply circuit, a rising edge clamping circuit, a MOSFET full-bridge inverter circuit, a falling edge clamping circuit, a damping absorption circuit and a transmitting load circuit; the low-voltage direct-current power supply circuit, the rising edge clamping circuit, the MOSFET full-bridge inverter circuit and the falling edge clamping circuit are sequentially connected in series; the MOSFET full-bridge inverter circuit, the damping absorption circuit and the emission load circuit are connected in parallel;
the low-voltage direct-current source circuit comprises a resistor R1, a resistor R2, a resistor R3, a flat top section low-voltage source E1 and a capacitor C1, wherein a first end of the resistor R1 is connected with a first end of the resistor R2, a second end of the resistor R2 is connected with a first end of a resistor R3, a second end of the resistor R3 is grounded, a second end of the resistor R1 is connected with a first end of the flat top section low-voltage source E1, a second end of the flat top section low-voltage source E1 is grounded, a second end of the resistor R1 is also connected with a first end of the capacitor C1, and a second end of the capacitor;
the rising edge clamp circuit includes: the circuit comprises a clamp control switch Q5, a rising edge high-voltage clamp source E2, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, an AND gate, an OR gate, an operational amplifier CP1, a resistor R5, a diode D8 and a diode D9; the clamp control switch Q5 is a MOSFET, the drain of the clamp control switch Q5 is connected to the first end of a rising edge high-voltage clamp source E2, the second end of the rising edge high-voltage clamp source E2 is grounded, the source of the clamp control switch Q5 is connected to the cathode of a diode D8, the anode of a diode D8 is connected to the second end of a first resistor R1, the gate of the clamp control switch Q5 is connected to the output end of an and gate, the first input end of the and gate is connected to the output end of an operational amplifier, the second input end of the and gate is connected to the output end of an or gate, the first input end of the or gate is connected to a control signal S1, and the second input end of the or; the positive electrode of the operational amplifier CP1 is connected with the first end of a third resistor R3, the negative electrode of the operational amplifier CP1 is connected with an AC-DC low-voltage high-power supply, the negative electrode of the operational amplifier CP1 is grounded through a resistor R5, the positive electrode of the diode D9 is connected with the source electrode of a clamping control switch Q5, the negative electrode of the diode D9 is connected with an AC-DC low-voltage high-power supply, the positive electrode of the diode D10 is connected with an AC-DC low-voltage high-power supply, the first end of the E2 is further connected with a capacitor C2, the second end of the capacitor C2 is connected with the first end of a capacitor C4, the second end of the capacitor C4 is grounded, the first end of the capacitor C2 is further connected with the first end of a capacitor C3;
the MOSFET full-bridge inverter circuit comprises a power switch Q1, a power switch Q2, a power switch Q3, a power switch Q4 and a diode D10, wherein the power switch Q1, the power switch Q2, the power switch Q3 and the power switch Q4 are MOSFETs, the drain of the power switch Q1 is connected with the anode of a diode D10, the cathode of a diode D10 is connected with the drain of a power switch Q2, the grid of the power switch Q1 is connected with a control signal S1, the source of the power switch Q1 is connected with the drain of a power switch Q3, the grid of the power switch Q3 is connected with a control signal S2, the source of the power switch Q2 is grounded, the grid of the power switch Q2 is connected with a control signal S2, the source of the power switch Q2 is connected with the drain of the power switch Q2, and the source of the power switch Q;
the falling edge clamp circuit includes: a resistor R4, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a falling edge high voltage clamping source E3 and a diode D11; the first end of the resistor R4 is connected with the cathode of the diode D10, the second end of the resistor R4 is grounded, the first end of the ground resistor R4 is further connected with the first end of the capacitor C6, the second end of the capacitor C6 is connected with the first end of the capacitor C8, the second end of the capacitor C8 is grounded, the first end of the capacitor C6 is further connected with the first end of the capacitor C7, the second end of the capacitor C7 is connected with the first end of the capacitor C9, the second end of the capacitor C9 is grounded, the first end of the capacitor C7 is further connected with the cathode of the diode D11, the anode of the diode D11 is connected with the first end of the falling edge high-voltage clamping source E3;
the damping absorption circuit comprises a power switch Q6, a power switch Q7 and a resistor R6, wherein the drain of the power switch Q6 is connected with the source of the power switch Q1, the grid of the power switch Q6 is suspended, the source of the power switch Q6 is connected with the first end of the resistor R6, the second end of the resistor R6 is connected with the source of a power switch Q7, the grid of the power switch Q7 is suspended, and the drain of the power switch Q7 is connected with the source of the power switch Q2;
the transmitting load circuit comprises an inductor L and a resistor R, wherein the first end of the inductor L is connected with the source electrode of the power switch Q1, the second end of the inductor L is connected with the first end of the resistor R, and the second end of the resistor R is connected with the source electrode of the power switch Q2.
10. A downhole time domain electromagnetic multi-component far detection system, comprising the downhole time domain electromagnetic multi-component far detection instrument of claim 9 and a surface control and data acquisition processing subsystem, wherein the downhole time domain electromagnetic multi-component far detection instrument and the surface control and data acquisition processing subsystem are connected through an armored photoelectric composite cable.
CN202010253077.5A 2020-04-02 2020-04-02 Downhole time domain electromagnetic multi-component remote detection instrument Pending CN111337988A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111812721A (en) * 2020-06-29 2020-10-23 中煤科工集团西安研究院有限公司 Omnibearing advanced detection device and method for hidden water damage at bottom of drill hole
US20220390640A1 (en) * 2021-03-15 2022-12-08 Institute Of Geology And Geophysics, Chinese Academy Of Sciences Multi-line source ground-borehole transient electromagnetic detection method and multi-line source ground-borehole transient electromagnetic detection

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111812721A (en) * 2020-06-29 2020-10-23 中煤科工集团西安研究院有限公司 Omnibearing advanced detection device and method for hidden water damage at bottom of drill hole
US20220390640A1 (en) * 2021-03-15 2022-12-08 Institute Of Geology And Geophysics, Chinese Academy Of Sciences Multi-line source ground-borehole transient electromagnetic detection method and multi-line source ground-borehole transient electromagnetic detection

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