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CN-121993198-A - Underground multi-range fluid dielectric parameter real-time measurement and overflow early warning system

CN121993198ACN 121993198 ACN121993198 ACN 121993198ACN-121993198-A

Abstract

The invention provides a downhole multi-range fluid dielectric parameter real-time measurement and overflow early warning system, wherein a transmitting electrode is positioned in the center of a measuring probe and is used for transmitting alternating current excitation signals to a slurry medium, a first measuring electrode and a second measuring electrode are symmetrically distributed relative to the periphery of the transmitting electrode and are used for collecting potential signals generated in the slurry medium, potential differences of the first measuring electrode and the second measuring electrode are used for calculating complex impedance of the slurry medium, a return electrode is arranged outside the first measuring electrode and the second measuring electrode in a surrounding manner and is positioned at the outermost ring of the measuring probe, and the return electrode is used as a return electrode of a current loop. The invention can be suitable for measuring high conductivity and high insulation fluid, and realize wide-range real-time accurate measurement of dielectric parameters of slurry, thereby timely identifying the change of slurry components and improving the early warning capability of underground abnormality.

Inventors

  • WANG ZIZHEN
  • LIU GONGHUI
  • YANG HONGWEI
  • LI JUN
  • LIAN WEI
  • Weng Chengkai

Assignees

  • 中国石油大学(北京)

Dates

Publication Date
20260508
Application Date
20260408

Claims (10)

  1. 1. The downhole multi-range fluid dielectric parameter real-time measurement and overflow early warning system (100) is characterized by comprising: the drilling tool (1) comprises a drill collar (11) and a drill bit (12) connected with the drill collar (11); The measuring probe (2) is arranged on the drill collar (11), the measuring probe (2) comprises four annular electrodes forming a current loop, an insulating layer is filled between the annular electrodes, the four annular electrodes are respectively corresponding to a transmitting electrode (A), a first measuring electrode (M), a second measuring electrode (N) and a reflux electrode (B), the transmitting electrode (A) is positioned in the center of the measuring probe (2) and is used for transmitting alternating current excitation signals to a mud medium, the first measuring electrode (M) and the second measuring electrode (N) are symmetrically distributed relative to the periphery of the transmitting electrode (A) and are used for collecting potential signals generated in the mud medium, potential differences of the first measuring electrode (M) and the second measuring electrode (N) are used for calculating complex impedance of the mud medium, the reflux electrode (B) is annularly arranged outside the first measuring electrode (M) and the second measuring electrode (N) and is positioned on the outermost ring of the measuring probe (2), and the reflux electrode (B) is used as a return electrode of the current loop.
  2. 2. The system for real-time measurement and overflow pre-warning of downhole multi-range fluid dielectric parameters according to claim 1, wherein the system (100) for real-time measurement and overflow pre-warning of downhole multi-range fluid dielectric parameters further comprises a measurement module (3) installed in an inner cavity of the drill collar (11), a plurality of measurement probes (2) are arranged around the periphery of the drill collar (11) at intervals and form probe assemblies, each measurement probe (2) is electrically connected with the measurement module (3), the number of the probe assemblies is two, the two probe assemblies are arranged at intervals along the axial direction of the drill collar (11), one probe assembly is used for measuring annular upper mud, the other probe assembly is used for measuring annular lower mud, and the measurement module (3) is used for calculating the dielectric constant and the electric conductivity of a mud medium according to potential signals collected by the probe assemblies and judging the spatial distribution characteristics of downhole fluid based on the difference of the electric parameters at different spatial positions so as to identify abnormal working conditions.
  3. 3. The downhole multi-range fluid dielectric parameter real-time measurement and overflow warning system according to claim 2, wherein the measurement module (3) comprises: An excitation current source circuit (31) for generating an alternating current signal with a set frequency, outputting the alternating current signal to a space between the transmitting electrode (A) and the return electrode (B), and forming an alternating current field in a downhole slurry medium for the first measuring electrode (M) and the second measuring electrode (N) to collect potential signals; a multi-way switch and mode switching circuit (32); The microprocessor (33), the excitation current source circuit (31), the multi-way switch and the mode switching circuit (32) are all electrically connected with the microprocessor (33), and the microprocessor (33) is used for controlling the multi-way switch and the mode switching circuit (32) to switch different measuring probes (2) and calculating the dielectric constants and the electric conductivities of the measuring probes (2).
  4. 4. A downhole multi-scale fluid dielectric parameter real-time measurement and overflow warning system according to claim 3, characterized in that the measurement probes (2) in two probe assemblies are arranged in a one-to-one correspondence, the microprocessor (33) being configured to Acquiring a total measured impedance between the corresponding measuring probes (2) in the two probe assemblies; decoupling inversion of the equivalent intrinsic complex impedance at each of the measurement probes (2); And calculating the dielectric constant and the conductivity of each measuring probe (2) according to the equivalent intrinsic complex impedance.
  5. 5. The downhole multi-range fluid permittivity real-time measurement and overflow warning system according to claim 4, characterized in that the microprocessor (33) is configured to calculate the total measured impedance between the corresponding measurement probes (2) in two of the probe assemblies according to the following formula : ; ; X is the serial number of the measuring probe (2) in the upper probe assembly; y is the serial number of the measuring probe (2) corresponding to the xth measuring probe (2) in the lower probe assembly; Is equivalent to intrinsic complex impedance; Is a geometric constant; is the conductivity of the slurry medium; Dielectric constant of slurry medium; 。
  6. 6. the downhole multi-scale fluid permittivity real-time measurement and overflow warning system according to claim 5, wherein the microprocessor (33) is configured to calculate the permittivity, conductivity at each of the measurement probes (2) according to the following formula: Equivalent intrinsic complex impedance; Conductivity of the material; A dielectric constant; Is a geometric constant; ; 。
  7. 7. The downhole multi-scale fluid permittivity parameter real-time measurement and overflow warning system according to claim 6, wherein the microprocessor (33) is configured to: If | |≈| I, judging that the fluid is uniformly distributed; If | | | I, then determine above the gas collection; If | | | And (3) judging the deposition of the rock debris below.
  8. 8. A downhole multi-range fluid dielectric parameter real-time measurement and overflow warning system according to any of claims 3-7, characterized in that the measurement module (3) further comprises a filtering module and an analogue-to-digital converter (37), the filtering module comprising a high-pass filter (34), a rectifier (35) and a low-pass filter (36), the measurement probe (2) being signally connected to the microprocessor (33) via the high-pass filter (34), the rectifier (35), the low-pass filter (36) and the analogue-to-digital converter (37); and/or the number of the groups of groups, The measuring module (3) further comprises a USB interface for data backup and a storage circuit (38) for offline analysis; and/or the number of the groups of groups, The measurement module (3) further comprises a communication circuit (39) for communicating with a surface monitor.
  9. 9. A downhole multi-scale fluid permittivity real-time measurement and overflow warning system according to any of claims 3-7, wherein the measurement module (3) further comprises: a temperature sensor (301) electrically connected to the microprocessor (33) and adapted to detect a current temperature of the measuring module (3); and the voltage monitoring module (302) is electrically connected with the microprocessor (33) and is used for detecting the current voltage of the measuring module (3).
  10. 10. The downhole multi-range fluid dielectric parameter real-time measurement and overflow warning system according to any of claims 1 to 7, characterized in that the periphery of the drill collar (11) is provided with a mounting groove, the measurement probe (2) is mounted in the mounting groove, and the peripheral height of the mounting groove is lower than the peripheral height of the drill collar (11), so that the outer surface of the measurement probe (2) is lower than the outer surface of the drill collar (11); and/or the number of the groups of groups, The periphery of the measuring probe (2) is provided with an anti-abrasion belt, and the peripheral height of the anti-abrasion belt is higher than that of the annular electrode; and/or the number of the groups of groups, An O-shaped sealing ring and insulating glue are arranged at the joint of the measuring probe (2) and the drill collar (11); and/or the number of the groups of groups, The insulation gap among the first measuring electrode (M), the second measuring electrode (N) and the emitting electrode (A) is 5 mm-8 mm; and/or the number of the groups of groups, The insulation gap among the first measuring electrode (M), the second measuring electrode (N) and the return electrode (B) is 5 mm-8 mm; and/or the number of the groups of groups, The thicknesses of the first measuring electrode (M), the second measuring electrode (N) and the reflux electrode (B) are not smaller than 3 mm-5 mm; and/or the number of the groups of groups, The thickness of the emitting electrode (A) is more than or equal to 5mm.

Description

Underground multi-range fluid dielectric parameter real-time measurement and overflow early warning system Technical Field The invention belongs to the technical field of petroleum drilling, and particularly relates to an underground multi-range fluid dielectric parameter real-time measurement and overflow early warning system. Background In drilling operations, the electrical properties of the drilling fluid (mud) are closely related to the components it contains. When an anomaly occurs downhole (e.g., formation fluid invasion causes a kick), the dielectric parameters (e.g., resistivity, permittivity, etc.) of the mud may change significantly. In the prior art, a mud sample is usually collected at a surface mud outlet or an electrical parameter change of the downhole mud is remotely monitored by using a measurement while drilling tool to identify whether the mud contains gas or oil. However, the surface monitoring method is subject to the inherent hysteresis of mud circulation, and significant delay exists between the overflow occurring underground to the surface and the effective monitoring signal is obtained, so that the timeliness requirement of early warning is difficult to meet. Therefore, the real-time monitoring of the mud state is directly carried out underground, and the timeliness and accuracy of abnormal working condition identification can be improved. The underground working condition is complex, the difference of the electrical properties of different types of drilling fluids is large, the water-based mud contains salt ions and has strong conductivity, and the oil-based mud has almost low insulation conductivity. It is difficult for a single type of sensor to cover such a wide range of resistivity and dielectric constant variations. For example, conventional resistivity sensors have weak signals that are difficult to measure in high resistivity slurries (oil-based), while capacitive sensors in high conductivity slurries (water-based) may have inaccurate measurements due to dielectric loss effects. This has caused existing while-drilling monitoring approaches to suffer from limitations in dealing with different mud media. Disclosure of Invention The invention mainly aims to provide a downhole multi-range fluid dielectric parameter real-time measurement and overflow early warning system, and aims to solve the technical problem that a single type of sensor is difficult to cover a wide range of resistivity and dielectric constant changes in the prior art. In order to achieve the above-mentioned object, the present invention provides a downhole multi-range fluid dielectric parameter real-time measurement and overflow pre-warning system, the downhole multi-range fluid dielectric parameter real-time measurement and overflow pre-warning system includes: the drilling tool comprises a drill collar and a drill bit connected with the drill collar; The measuring probe is arranged on the drill collar and comprises four annular electrodes forming a current loop, an insulating layer is filled between the annular electrodes, the four annular electrodes are respectively and correspondingly a transmitting electrode, a first measuring electrode, a second measuring electrode and a reflux electrode, wherein the transmitting electrode is positioned in the center of the measuring probe and is used for transmitting alternating current excitation signals to slurry media, the first measuring electrode and the second measuring electrode are symmetrically distributed relative to the periphery of the transmitting electrode and are used for collecting potential signals generated in the slurry media, potential differences of the first measuring electrode and the second measuring electrode are used for calculating complex impedance of the slurry media, the reflux electrode is arranged outside the first measuring electrode and the second measuring electrode in a surrounding mode and is positioned on the outermost ring of the measuring probe, and the reflux electrode is used as a return electrode of the current loop. In the embodiment of the invention, the underground multi-range fluid dielectric parameter real-time measurement and overflow early warning system further comprises a measurement module arranged in the inner cavity of the drill collar, a plurality of measurement probes are arranged around the periphery of the drill collar at intervals and form probe assemblies, each measurement probe is electrically connected with the measurement module, the number of the two probe assemblies is two, the two probe assemblies are arranged at intervals along the axial direction of the drill collar, one probe assembly is used for measuring annulus upper mud, the other probe assembly is used for measuring annulus lower mud, and the measurement module is used for calculating the dielectric constant and the electric conductivity of a mud medium according to potential signals acquired by the probe assemblies and judging the spatial distr