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CN-121993049-A - Downhole stratum casing distance magnetic detection method and system

CN121993049ACN 121993049 ACN121993049 ACN 121993049ACN-121993049-A

Abstract

The invention discloses a method and a system for magnetic detection of a distance between underground stratum sleeves, which belong to the technical field of oil and gas well drilling, and the method comprises the following steps that S1, a steel short sleeve is fixed on a bracket; the method comprises the steps of S2, connecting a first sleeve and a second sleeve together through threads to form an outer sleeve, then placing the outer sleeve on a supporting pipe rack, S3, processing collected rock blocks into a plurality of cylindrical rock columns, pushing the cylindrical rock columns into the outer sleeve, S4, installing a magnetic probe, a circuit board and a battery on the inner wall of a titanium alloy shell, wherein the circuit board is electrically connected with the battery, the magnetic probe is electrically connected with the circuit board, S5, placing the outer sleeve between a steel short sleeve and the titanium alloy shell, opening the magnetic probe, and transmitting magnetic lines of force through the cylindrical rock columns along the axial direction of the outer sleeve until the magnetic probe touches the steel short sleeve. The invention can meet the field requirements of the oil field, has simple integral magnetic detection operation and is beneficial to improving the magnetic detection accuracy.

Inventors

  • GAO YONGWEI
  • LIU KUNFENG
  • LIU KEQIANG
  • ZHAO WENZHUANG
  • WEI HAIFANG
  • WU GUANG
  • YANG MIN
  • ZHOU SHANSHAN
  • JIANG HE
  • LI KUNPENG

Assignees

  • 中国石油天然气集团有限公司
  • 中国石油集团川庆钻探工程有限公司

Dates

Publication Date
20260508
Application Date
20241106

Claims (10)

  1. 1. A method of downhole formation casing distance magnetic sounding comprising the steps of: s1, fixing a steel short sleeve (1) on a bracket (2); s2, connecting the first sleeve (3) and the second sleeve (4) together through threads to form an outer sleeve (5), and then placing the outer sleeve (5) on a support pipe rack (6); S3, processing the collected rock blocks into a plurality of cylindrical rock columns (7), and pushing the cylindrical rock columns (7) into the outer sleeve (5); S4, mounting a magnetic probe (9), a circuit board (10) and a battery (11) on the inner wall of the titanium alloy shell (8), wherein the circuit board (10) is electrically connected with the battery (11), and the magnetic probe (9) is electrically connected with the circuit board (10); S5, placing the outer sleeve (5) between the steel short sleeve (1) and the titanium alloy outer shell (8), opening the magnetic probe (9), and enabling the magnetic probe (9) to emit magnetic lines of force to pass through the cylindrical rock column (7) along the axial direction of the outer sleeve (5) until the magnetic lines of force touch the steel short sleeve (1).
  2. 2. A method of distance magnetic sounding of a casing in a well rock according to claim 1, wherein in step S1, the length of the steel short casing (1) is 500mm.
  3. 3. The method of claim 1, wherein in the step S2, the lengths of the first casing (3) and the second casing (4) are 7m, the outer diameters are 244.5mm, and the inner diameters are 224.4mm.
  4. 4. The method of claim 1, wherein in the step S5, the placement of the outer casing (5) between the steel short casing (1) and the titanium alloy outer casing (8) means that a first gap is left between one end of the outer casing (5) and the steel short casing (1), and a second gap is left between the other end of the outer casing (5) and the titanium alloy outer casing (8).
  5. 5. The method of claim 1, wherein the first gap is 2-3mm and the second gap is 1-2mm.
  6. 6. A method for distance magnetic prospecting of a casing in a well according to claim 1, wherein in said step S2, the support tube holder (6) comprises a first tube holder (12) and a second tube holder (13), the first tube holder (12) is located below the first casing (3), and the second tube holder (13) is located below the second casing (4).
  7. 7. The method for detecting the distance between underground rock stratum sleeves by magnetic detection according to claim 1, wherein in the step S3, the number of the cylindrical rock columns (7) is four, and the gap between any two adjacent cylindrical rock columns (7) is 1-2mm.
  8. 8. A method for distance magnetic detection of a casing in a downhole formation according to claim 1, wherein in step S3, the central axes of any two adjacent cylindrical rock columns (7) coincide.
  9. 9. A method of downhole formation casing distance magnetic prospecting according to claim 1, wherein in step S5, the magnetic probe (9) corresponds to the central axis of the cylindrical rock column (7).
  10. 10. The underground stratum casing distance magnetic detection system comprises an outer casing (5) for placing a cylindrical rock column (7), and is characterized by further comprising a magnetic detection tool, a steel short casing (1), a support pipe rack (6) and a support (2), wherein the steel short casing (1) is fixed on the support (2), the outer casing (5) is fixed on the support pipe rack (6), the outer casing (5) is located between the steel short casing (1) and the magnetic detection tool, the magnetic detection tool comprises a titanium alloy outer shell (8), a magnetic probe (9), a circuit board (10) and a battery (11), the circuit board (10) is electrically connected with the battery (11), the magnetic probe (9) is electrically connected with the circuit board (10), the magnetic probe (9), the circuit board (10) and the battery (11) are all fixed on the inner wall of the titanium alloy outer shell (8), and the magnetic probe (9) corresponds to the central axis of the cylindrical rock column (7).

Description

Downhole stratum casing distance magnetic detection method and system Technical Field The invention relates to the technical field of oil and gas well drilling, in particular to a method and a system for magnetic detection of a downhole stratum casing distance. Background In recent years, the need for anti-collision tools has been urgent in the well completion process. For the drilling data in the 90 th and the past of the last century, the data accuracy is poor or even lost due to the influence of the long-term and preservation mode, and the anti-collision working pressure is unprecedented in the secondary operation. The existing mature magnetic positioning tool mainly meets the requirement of steam-assisted gravity drainage exploitation, the basic principle is that the active magnetic positioning tool needs to enter a magnetic source under a target well when in use, the production of a temporary well is affected, and the use is limited. The Chinese patent document with publication number CN118169765A and publication date 2024, month 06 and 11 discloses an underground pipeline detection method which is characterized by comprising the following steps: S1, determining a detection area of an underground pipeline, acquiring the type and the design depth of the pipeline installed in the detection area, and establishing a three-dimensional geological model containing the pipeline in the detection area; s2, selecting a path pipeline, establishing a three-dimensional coordinate system on the three-dimensional geological model, splitting the path pipeline into uniform sub-detection sections along the length direction, and acquiring coordinates of the sub-detection sections and ground coordinates of a signal receiving device; S3, the pipeline robot carries electromagnetic signal transmitting equipment to sequentially reach the sub-detection section, calculates the actual depth of the path pipeline in the rock stratum, and calculates the offset coefficient of the path pipeline according to the design depth; S4, calculating the depth of adjacent pipelines around the path pipeline to obtain a path for detecting the adjacent pipelines on the ground; S5, calculating offset coefficients of adjacent pipelines; And S6, evaluating the compression state of the underground rock stratum on the pipeline and the failure risk of the pipeline according to the offset coefficients of the path pipeline and the adjacent pipelines. The underground pipeline detection method disclosed in the patent document has the advantages that the detection range of the underground pipeline is large, and the obtained pipeline detection data are rich. The method is characterized in that a transmitting frame with proper size is arranged on the ground, a transient electromagnetic three-component magnetic probe and a gyro inclinometer are put to a position below a casing fault point from a wellhead, three-component transient electromagnetic data at the position of the underground magnetic probe are collected, the buried depth of a casing head of a lower section and the direction of a relative three-component magnetic probe are determined by analyzing three-component pure abnormal response characteristics of the casing of the fault and horizontal component vector synthesis statistics, the geographical azimuth of the deviation of the casing of the lower section is detected by the gyro inclinometer, so that the accurate position of the casing of the lower section in the underground is obtained, and the three-component magnetic probe is used for collecting transient magnetic field three-components at the position of the underground magnetic probe. The underground fracture casing head azimuth detection method based on the ground well transient electromagnetic method disclosed by the patent document can determine the azimuth and the burial depth of the large-displacement fracture casing head relative to the upper well hole, and is beneficial to improving the success rate of fracture casing repair. However, in the prior art represented by the above patent documents, the entire detection operation is complicated, and the detection accuracy is poor. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides the underground rock stratum casing distance magnetic detection method and system, which can meet the field requirements of an oil field, are simple in integral magnetic detection operation and are beneficial to improving the magnetic detection accuracy. The invention is realized by the following technical scheme: A method of downhole formation casing distance magnetic sounding comprising the steps of: S1, fixing a steel short sleeve on a bracket; S2, connecting the first sleeve and the second sleeve together through threads to form an outer sleeve, and then placing the outer sleeve on a support pipe rack; s3, processing the collected rock blocks into a plurality of cylindrical rock columns, and pushing the cylindrical roc