CN-121993177-A - Double-insulation short section electromagnetic wave measurement while drilling device and method

CN121993177ACN 121993177 ACN121993177 ACN 121993177ACN-121993177-A

Abstract

The invention relates to the technical field of oil and gas well engineering measurement and underground information transmission, in particular to a double-insulation short section electromagnetic wave measurement while drilling device and a method, wherein the device comprises an upper insulation short section, a lower insulation short section and a middle metal drill collar shell; the middle metal drill collar shell is characterized in that the top of the middle metal drill collar shell is connected with an upper insulation nipple, the bottom of the middle metal drill collar shell is connected with a lower insulation nipple, a battery nipple, a central control nipple, a measuring nipple and a transmitting circuit nipple are arranged in the middle metal drill collar shell, the battery nipple is positioned at the top of the metal drill collar shell, the central control nipple is positioned below the battery nipple, the measuring nipple is positioned below the central control nipple, and the transmitting circuit nipple is positioned below the measuring nipple. The invention can solve the problems of insufficient transmission depth, low anti-interference capability and obvious contradiction between power consumption and heat dissipation of the existing single-insulation short section device in a low-resistance stratum.

Inventors

ZHANG ZHENHUA
ZHAI XIPING
LI RUNQI
WANG HAIQI
XU YUEQING
CAI WEI
ZHAO ZHIXUE
GAO MING
PEI FEI
XU YUNLONG
WANG ZHENLEI
WANG SHUQING
LIU HAIBO
YU HONGBO

Assignees

大庆钻探工程有限公司
中国石油天然气集团有限公司

Dates

Publication Date: 20260508
Application Date: 20251225

Claims (9)

1. The double-insulation short section electromagnetic wave measurement while drilling device is characterized by comprising an upper insulation short section (1), a lower insulation short section (2) and a middle metal drill collar shell (3); the top of the middle metal drill collar shell (3) is connected with the upper insulation nipple (1), and the bottom of the middle metal drill collar shell is connected with the lower insulation nipple (2); a battery nipple (4), a central control nipple (5), a measuring nipple (6) and a transmitting circuit nipple (7) are arranged in the middle metal drill collar shell (3); The battery nipple (4) is located at the top of the middle metal drill collar shell (3), the central control nipple (5) is located below the battery nipple (4), the measurement nipple (6) is located below the central control nipple (5), and the transmitting circuit nipple (7) is located below the measurement nipple (6).
2. The dual insulation nipple electromagnetic wave measurement while drilling device according to claim 1, wherein: the upper insulation pup joint (1) is of a cylindrical structure, two ends are metal, and the middle is an insulator; The lower end of the upper insulation pup joint (1) is connected with the middle metal drill collar shell (3) through threads; The structure of the lower insulation pup joint (2) is the same as that of the upper insulation pup joint (1), and the upper end of the lower insulation pup joint is connected with the middle metal drill collar shell (3) through threads; the outer side of the upper insulating nipple (1) is provided with a first electrode, and the outer side of the lower insulating nipple (2) is provided with a second electrode.
3. The dual insulation nipple electromagnetic wave measurement while drilling device according to claim 1, wherein: the battery nipple (4) adopts cylindrical battery groups to be coaxially arranged, and a high-temperature lithium thionyl chloride battery is arranged in the battery nipple; The battery nipple (4) is connected with the transmitting circuit nipple (7) through a lead, and the battery nipple (4) is used for providing stable electric energy for the transmitting circuit.
4. The dual insulation nipple electromagnetic wave measurement while drilling device according to claim 1, wherein: The measuring nipple (6) is connected with the central control nipple (5) through a flexible flat cable; The central control pup joint (5) is used for data acquisition, modulation and emission control; The transmission circuit nipple (7) is located in the middle of accuse nipple (5) and measures nipple (6) below, transmission circuit nipple (7) have first output and second output, and first output is connected with last insulating nipple (1) electrode electricity, and the second output is connected with insulating nipple (2) electrode electricity down, transmission circuit nipple (7) are used for transmitting the signal of telecommunication.
5. The double-insulation short section electromagnetic wave measurement while drilling method is characterized by comprising the following steps of: step S1, establishing a three-dimensional model of a drilling tool comprising stratum, slurry, a well bore and a double-insulation nipple in software; S2, inputting parameter stratum resistivity rho, slurry resistivity rho m , target transmission depth D, well diameter D, dipole length L and excitation parameters in the three-dimensional model established in the step S1; S3, selecting a low-frequency electromagnetic field solver in software, setting excitation ports on metals on two sides of the insulating nipple, and setting dipole length L, stratum resistivity rho, excitation parameters and slurry resistivity rho m as scanning variables; Step S4, setting a virtual ground receiving point at a remote place of the model, reading field strengths of an electric field and a magnetic field of the point and a signal to noise ratio, and judging whether the requirements are met; Step S5, analyzing the calculation results of the step S2-step S4 to obtain optimal lengths L and initial emission parameters theta 0 aiming at different lengths, and solidifying the optimal lengths L and the initial emission parameters theta 0 into a parameter mapping table; s6, according to the optimal length L output in the step S5, structural assembly is achieved by replacing or splicing a middle metal drill collar shell, an initial emission parameter set theta 0 is written into a tool controller, and the structure and parameter loading before well running are completed; Step S7, after the tool is electrified, a self-checking flow is executed, and the working state and switching consistency of the transmitting stage, the sampling stage and the matching switching mechanism are detected, so that the boosting, matching and sampling links are ensured to be in a controllable state; step S8, outputting a low-energy test sequence on the premise of not entering normal high-power transmission, and synchronously sampling output voltage and current waveforms for subsequent impedance and power index estimation; Step S9, calculating equivalent impedance and power indexes based on the acquired data in step S8, and calculating actual power S indexes, thereby updating the boost gear, the matched gear, the target power and the duty ratio to form an updated parameter set theta 1 ; And S10, entering a normal transmitting stage, executing closed-loop control under constraint conditions such as constant power or voltage limiting and current limiting, and performing linkage adjustment on boost output, a matched gear and a duty ratio according to a control strategy to enable transmission to be at a stable working point meeting deep transmission requirements, and continuously monitoring impedance and power index change.
6. The dual insulation nipple electromagnetic wave while drilling measurement method according to claim 5, wherein step S4 comprises: The ground receiving field intensity value Ew L is larger than or equal to the minimum value Ew thr allowed by the ground receiving field intensity, the ground receiving data signal-to-noise ratio value SNR D is larger than or equal to the minimum value SNR thr allowed by the ground data signal-to-noise ratio, and the reliable transmission with depth D can be realized by the parameter combination without triggering voltage, current and power overrun.
7. The dual insulation nipple electromagnetic wave while-drilling measurement method according to claim 5, wherein step S10 comprises: and when the impedance estimated value continuously deviates from the target working interval and is difficult to recover to a stable working point through conventional linkage adjustment, re-executing the steps S8-S9, and returning to the step S10 to continue the closed-loop operation.
8. The dual insulation nipple electromagnetic wave while-drilling measurement method according to claim 5, wherein step S10 comprises: When the characteristics of overvoltage, overcurrent, overtemperature or suspected leakage and breakdown faults are detected, a protection and derating strategy is entered, soft derating is preferably executed, the voltage, the current and the power are monitored to be within the limit values and kept stable for a preset duration, and the protection is exited and the step S10 is returned to continue the closed-loop operation; And if the temperature or the working condition is normal, executing the steps S8-S9 again, allowing the transmission to be restarted, and returning to the step S10 to continue the closed-loop operation.
9. The dual insulation nipple electromagnetic wave while-drilling measurement method according to claim 5, wherein step S9 comprises: The calculation formula of the equivalent impedance is as follows: |Z eq |=V rms /I rms Wherein, V rms is the effective value of the output voltage of the transmitting end, V rms is the effective value of the output current of the transmitting end, A is the effective value of the output current of the transmitting end, Z eq is the equivalent transmitting impedance amplitude index, omega; the actual output power calculation formula is: S=V rms ·I rms Wherein V rms is the effective value of the output voltage of the transmitting end, V, I rms is the effective value of the output current of the transmitting end, A and S are the actual output power and W.

Description

Double-insulation short section electromagnetic wave measurement while drilling device and method Technical Field The invention belongs to the technical field of oil-gas well engineering measurement and underground information transmission, and particularly relates to a double-insulation short section electromagnetic wave measurement while drilling device and method. Background Electromagnetic wave measurement while drilling is widely adopted in complex wellbores, high-impedance formations and air drilling as a downhole information transmission mode independent of mud pressure pulses. In the existing engineering application, the international oil service company is an electromagnetic wave transmitter with a single insulation nipple structure as commonly used by domestic enterprises. This type of structure typically provides a single gap sub in the middle of the drill string, which, by blocking the drill string metal conduction path, forces the transmitted current to close through the formation, thereby forming a low frequency asymmetric electric dipole to radiate electromagnetic signals to the surface. The single gap sub construction has inherent technical limitations. The upper drill string is huge in length, current decays exponentially along the drill string, and only an area about 1-3 m above the insulating pup joint effectively contributes to a dipole field, so that the length of an effective electrode is short and uncontrollable, and the electromagnetic wave emission capacity while drilling is limited. Attempts have been made to increase the transmission depth, including increasing the transmission power or using repeaters, but all suffer from high power consumption, high cost, poor reliability, and the like. Therefore, how to structurally extend the effective electrode length, increase the emission voltage and enhance the transmission performance becomes a bottleneck for further development of electromagnetic wave measurement while drilling technology. Another key disadvantage is that the current boundary conditions are not controllable. Because only one insulation breakpoint exists, the upper drill string always forms a virtual electrode, the length, the structure, the number of joints and the change of drilling tool combinations can influence current distribution, so that the effective dipole length cannot be designed, and system parameters (emission impedance, a matching network, a waveform modulation mode and the like) cannot work according to the optimal conditions, and the performance consistency of the transmitter is severely restricted. The early-pushed electromagnetic wave measurement while drilling tool mainly relates to an insulation short section structure, antenna arrangement and a ground demodulation method. The insulating pup joint in these instruments is single position setting, and effective electrode length is limited, therefore launches voltage under the constant power condition and promotes the restriction. Because the single insulating structure only forms a single-sided current confinement, the dipole structure is an incomplete asymmetric dipole in nature, and the current cannot form a closed and controlled symmetric current distribution underground, so that a predictable electromagnetic field model is difficult to build in a casing-stratum complex medium. For this structure, no technical means for controllably designing the effective electrode length, actively optimizing the emission impedance, or defining the current path have emerged in the industry. In addition, it is also proposed to boost the output power by improving the transmitter circuit, but the contradiction between power consumption and heat dissipation is obvious, and the problem of insufficient effective electrode length is not solved from the structural point of view. Most of the existing schemes focus on short-range transmission, repeater technology, power/signal coupling, etc. Despite the performance improvements achieved locally, single gap sub designs are common, resulting in insufficient effective electrode spacing. Disclosure of Invention The invention provides a double-insulation short section electromagnetic wave measurement while drilling device and a method thereof, which are used for solving the problems of insufficient transmission depth, low anti-interference capability and obvious contradiction between power consumption and heat dissipation of the existing single-insulation short section device in a low-resistance stratum. The invention provides a double-insulation nipple electromagnetic wave measurement while drilling device, which comprises an upper insulation nipple, a lower insulation nipple and a middle metal drill collar shell; the top of the middle metal drill collar shell is connected with an upper insulation nipple, and the bottom of the middle metal drill collar shell is connected with a lower insulation nipple; A battery nipple, a central control nipple, a measurement nipple and a transmi