Downhole rock stratum casing distance magnetic detection method and system

Abstract

The invention discloses an underground rock stratum casing distance magnetic detection method and system, and belongs to the technical field of oil and gas well drilling. The method comprises the following steps that S1, a steel short casing is fixed to a support; s2, the first casing pipe and the second casing pipe are connected together through threads to form an outer casing pipe, and then the outer casing pipe is placed on a supporting pipe frame; s3, processing the collected rock blocks into a plurality of cylindrical rock pillars, and pushing the cylindrical rock pillars into the outer sleeve; s4, a magnetic probe, a circuit board and a battery are installed on the inner wall of the titanium alloy outer shell, the circuit board is electrically connected with the battery, and the magnetic probe is electrically connected with the circuit board; and S5, the outer sleeve is placed between the steel short sleeve and the titanium alloy outer shell, the magnetic probe is opened, and magnetic lines emitted by the magnetic probe penetrate through the cylindrical rock pillar in the axial direction of the outer sleeve till the magnetic lines touch the steel short sleeve. The oil field on-site requirement can be met, the overall magnetic detection operation is simple, and the magnetic detection accuracy can be improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well drilling technology, and in particular to a method and system for magnetic exploration of the distance between the casing and the well bed. Background Technology

[0002] In recent years, the demand for collision prevention tools has become extremely urgent during drilling and well completion processes. For drilling data from the 1990s and earlier, due to the age of the data and the influence of preservation methods, the accuracy of the data is poor or even missing, making collision prevention work more challenging during secondary operations.

[0003] Currently, the more mature magnetic positioning tools are mainly used to meet the needs of steam-assisted gravity drainage oil extraction. The basic principle is an active magnetic positioning tool. When using it, a magnetic source needs to be inserted downhole into the target well, which affects the production of adjacent wells and has limitations in use.

[0004] Chinese patent document CN118169765A, published on June 11, 2024, discloses a method for detecting underground pipelines, characterized by comprising the following steps: S1: Determine the detection area for underground pipelines, obtain the types and design depths of pipelines installed within the detection area, and establish a three-dimensional geological model containing the pipelines within the detection area. S2: Select the path pipeline, establish a three-dimensional coordinate system on the three-dimensional geological model, divide the path pipeline into uniform sub-detection segments along the length direction, and obtain the coordinates of the sub-detection segments and the ground coordinates of the signal receiving device. S3: The pipeline robot, carrying an electromagnetic signal transmitting device, arrives at the sub-detection section in sequence, calculates the actual depth of the pipeline path in the rock strata, and calculates the offset coefficient of the pipeline path based on the design depth. S4: Calculate the depth of neighboring pipes around the path pipe to obtain the path of the neighboring pipes on the ground; S5: Calculate the offset coefficient of adjacent pipes; S6: Based on the offset coefficients of the pipeline along the route and adjacent pipelines, assess the pressure state of the underground rock strata on the pipeline and the risk of pipeline failure.

[0005] The underground pipeline detection method disclosed in this patent document has a large detection range and obtains abundant pipeline detection data.

[0006] Chinese patent document CN117868804A, published on April 12, 2024, discloses a method for detecting the location of a misaligned casing head in a downhole well based on the transient electromagnetic method. The method involves setting up a suitable-sized transmitting frame on the ground, lowering a transient electromagnetic three-component magnetic probe and a gyro inclinometer from the wellhead to a position below the casing misalignment point, collecting three-component transient electromagnetic data at the probe's location, and determining the burial depth and orientation relative to the three-component magnetic probe by analyzing the three-component pure anomaly response characteristics and horizontal component vector synthesis statistics of the misaligned casing. The gyro inclinometer detects the geographical orientation of the lower casing section's offset, thus determining the accurate location of the lower casing section downhole. The three-component magnetic probe is used to collect the three components of the transient magnetic field at the probe's location; the data collected by the gyro inclinometer is used to determine the attitude information of the downhole magnetic probe.

[0007] The patent document discloses a method for detecting the orientation of a misaligned casing head in a downhole well based on transient electromagnetic methods. This method can determine the orientation and burial depth of a large-displacement misaligned casing head relative to the upper wellbore, which helps to improve the success rate of repairing misaligned casing.

[0008] However, the existing technologies represented by the aforementioned patent documents are relatively complex in terms of overall detection operation and have poor detection accuracy. Summary of the Invention

[0009] In order to overcome the shortcomings of the prior art, this invention provides a method and system for magnetic exploration of casing distance in downhole formations. This invention can meet the requirements of oilfield sites, and not only is the overall magnetic exploration operation simple, but it also helps to improve the accuracy of magnetic exploration.

[0010] This invention is achieved through the following technical solution: A method for magnetic exploration of casing distance in downhole formations, characterized by comprising the following steps: S1. Fix the short steel sleeve to the bracket; S2. Connect the first sleeve and the second sleeve together with threads to form an outer sleeve, and then place the outer sleeve on the support pipe rack; S3. Process the collected rock blocks into multiple cylindrical rock columns, and push the cylindrical rock columns into the outer casing. S4. Install a magnetic probe, a circuit board and a battery on the inner wall of the titanium alloy shell. The circuit board is electrically connected to the battery and the magnetic probe is electrically connected to the circuit board. S5. Place the outer sleeve between the short steel sleeve and the titanium alloy outer shell, turn on the magnetic probe, and the magnetic probe emits magnetic lines of force that pass through the cylindrical rock column along the axial direction of the outer sleeve until it touches the short steel sleeve.

[0011] In step S1, the length of the short steel sleeve is 500mm.

[0012] In step S2, the length of both the first sleeve and the second sleeve is 7m, the outer diameter is 244.5mm, and the inner diameter is 224.4mm.

[0013] In step S5, placing the outer sleeve between the steel short sleeve and the titanium alloy outer shell means that there is a first gap between one end of the outer sleeve and the steel short sleeve, and a second gap between the other end of the outer sleeve and the titanium alloy outer shell.

[0014] The first gap is 2-3mm, and the second gap is 1-2mm.

[0015] In step S2, the support frame includes a first support frame and a second support frame, with the first support frame located below the first sleeve and the second support frame located below the second sleeve.

[0016] In step S3, there are four cylindrical rock columns, and the gap between any two adjacent cylindrical rock columns is 1-2 mm.

[0017] In step S3, the central axes of any two adjacent cylindrical rock columns coincide.

[0018] In step S5, the magnetic probe corresponds to the central axis of the cylindrical rock column.

[0019] A downhole casing distance magnetic exploration system includes an outer casing for placing a cylindrical rock column. It is characterized by further including a magnetic exploration tool, a short steel casing, a support frame, and a bracket. The short steel casing is fixed to the bracket, and the outer casing is fixed to the support frame. The outer casing is located between the short steel casing and the magnetic exploration tool. The magnetic exploration tool includes a titanium alloy outer shell, a magnetic probe, a circuit board, and a battery. The circuit board is electrically connected to the battery, and the magnetic probe is electrically connected to the circuit board. The magnetic probe, circuit board, and battery are all fixed to the inner wall of the titanium alloy outer shell. The magnetic probe corresponds to the central axis of the cylindrical rock column.

[0020] The beneficial effects of this invention are mainly reflected in the following aspects: 1. This invention comprises: S1. Fixing a short steel sleeve onto a support; S2. Connecting a first sleeve and a second sleeve together via threads to form an outer sleeve, which is then placed on a support frame; S3. Processing the collected rock blocks into multiple cylindrical rock columns, and 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 the titanium alloy outer shell, with the circuit board electrically connected to the battery and the magnetic probe electrically connected to the circuit board; S5. Placing the outer sleeve between the short steel sleeve and the titanium alloy outer shell, turning on the magnetic probe, and having the magnetic probe emit magnetic lines of force that pass through the cylindrical rock columns along the axial direction of the outer sleeve until they hit the short steel sleeve. Compared with existing technologies, this invention can meet the requirements of oilfield sites, and not only is the overall magnetic exploration operation simple, but it also helps to improve the accuracy of magnetic exploration.

[0021] 2. The magnetic exploration method of this invention enables more targeted design of drilling anti-collision tools, which helps to reduce drilling and completion costs, and at the same time provides data basis for subsequent remote support.

[0022] 3. The magnetic detection system of this invention can meet different production needs, and the magnetic detection method is simple and easy to promote.

[0023] 4. The magnetic detection system of this invention has a simple overall structure, is easy to operate, and has good applicability. Attached Figure Description

[0024] The present invention will now be further described in detail with reference to the accompanying drawings and specific embodiments: Figure 1 This is a schematic diagram of the magnetic detection system of the present invention; The markings in the diagram are: 1. Steel short sleeve, 2. Support, 3. First sleeve, 4. Second sleeve, 5. Outer sleeve, 6. Supporting pipe rack, 7. Cylindrical rock column, 8. Titanium alloy outer shell, 9. Magnetic probe, 10. Circuit board, 11. Battery, 12. First pipe rack, 13. Second pipe rack. Detailed Implementation

[0025] Example 1 See Figure 1 A method for magnetic exploration of casing distance in downhole formations, comprising the following steps: S1. Fix the short steel sleeve 1 onto the bracket 2; S2. Connect the first sleeve 3 and the second sleeve 4 together by thread to form the outer sleeve 5, and then place the outer sleeve 5 on the support tube frame 6. S3. Process the collected rock blocks into multiple cylindrical rock columns 7, and push the cylindrical rock columns 7 into the outer casing 5; S4. Install a magnetic probe 9, a circuit board 10 and a battery 11 on the inner wall of the titanium alloy outer shell 8. The circuit board 10 is electrically connected to the battery 11 and the magnetic probe 9 is electrically connected to the circuit board 10. S5. Place the outer sleeve 5 between the steel short sleeve 1 and the titanium alloy outer shell 8, turn on the magnetic probe 9, and the magnetic probe 9 emits magnetic lines of force that pass through the cylindrical rock column 7 along the axial direction of the outer sleeve 5 until it touches the steel short sleeve 1.

[0026] This embodiment is the most basic implementation method. S1, fix the steel short sleeve 1 on the bracket 2; S2, connect the first sleeve 3 and the second sleeve 4 together by thread to form the outer sleeve 5, and then place the outer sleeve 5 on the support pipe rack 6; S3, process the collected rock blocks into multiple cylindrical rock columns 7, and push the cylindrical rock columns 7 into the outer sleeve 5; S4, install the magnetic probe 9, circuit board 10 and battery 11 on the inner wall of the titanium alloy outer shell 8. The circuit board 10 is electrically connected to the battery 11, and the magnetic probe 9 is electrically connected to the circuit board 10; S5, place the outer sleeve 5 between the steel short sleeve 1 and the titanium alloy outer shell 8, turn on the magnetic probe 9, and the magnetic probe 9 emits magnetic lines of force along the axial direction of the outer sleeve 5 through the cylindrical rock columns 7 until it touches the steel short sleeve 1. Compared with the prior art, this method can meet the requirements of the oilfield site. It is not only simple to operate the overall magnetic exploration, but also helps to improve the accuracy of magnetic exploration.

[0027] Example 2 See Figure 1 A method for magnetic exploration of casing distance in downhole formations, comprising the following steps: S1. Fix the short steel sleeve 1 onto the bracket 2; S2. Connect the first sleeve 3 and the second sleeve 4 together by thread to form the outer sleeve 5, and then place the outer sleeve 5 on the support tube frame 6. S3. Process the collected rock blocks into multiple cylindrical rock columns 7, and push the cylindrical rock columns 7 into the outer casing 5; S4. Install a magnetic probe 9, a circuit board 10 and a battery 11 on the inner wall of the titanium alloy outer shell 8. The circuit board 10 is electrically connected to the battery 11 and the magnetic probe 9 is electrically connected to the circuit board 10. S5. Place the outer sleeve 5 between the steel short sleeve 1 and the titanium alloy outer shell 8, turn on the magnetic probe 9, and the magnetic probe 9 emits magnetic lines of force that pass through the cylindrical rock column 7 along the axial direction of the outer sleeve 5 until it touches the steel short sleeve 1.

[0028] Preferably, in step S1, the length of the steel short sleeve 1 is 500mm.

[0029] In step S2, the length of the first sleeve 3 and the second sleeve 4 are both 7m, the outer diameter is 244.5mm, and the inner diameter is 224.4mm.

[0030] In step S5, placing the outer sleeve 5 between the steel short sleeve 1 and the titanium alloy outer shell 8 means that one end of the outer sleeve 5 is left with a first gap between it and the steel short sleeve 1, and the other end of the outer sleeve 5 is left with a second gap between it and the titanium alloy outer shell 8.

[0031] The first gap is 2mm and the second gap is 1mm.

[0032] This embodiment is a preferred implementation method. The magnetic exploration method enables the design of drilling anti-collision tools to be more targeted, which helps to reduce drilling and completion costs, and at the same time provides data basis for subsequent remote support.

[0033] Example 3 See Figure 1 A method for magnetic exploration of casing distance in downhole formations, comprising the following steps: S1. Fix the short steel sleeve 1 onto the bracket 2; S2. Connect the first sleeve 3 and the second sleeve 4 together by thread to form the outer sleeve 5, and then place the outer sleeve 5 on the support tube frame 6. S3. Process the collected rock blocks into multiple cylindrical rock columns 7, and push the cylindrical rock columns 7 into the outer casing 5; S4. Install a magnetic probe 9, a circuit board 10 and a battery 11 on the inner wall of the titanium alloy outer shell 8. The circuit board 10 is electrically connected to the battery 11 and the magnetic probe 9 is electrically connected to the circuit board 10. S5. Place the outer sleeve 5 between the steel short sleeve 1 and the titanium alloy outer shell 8, turn on the magnetic probe 9, and the magnetic probe 9 emits magnetic lines of force that pass through the cylindrical rock column 7 along the axial direction of the outer sleeve 5 until it touches the steel short sleeve 1.

[0034] In step S1, the length of the steel short sleeve 1 is 500mm.

[0035] In step S2, the length of the first sleeve 3 and the second sleeve 4 are both 7m, the outer diameter is 244.5mm, and the inner diameter is 224.4mm.

[0036] In step S5, placing the outer sleeve 5 between the steel short sleeve 1 and the titanium alloy outer shell 8 means that one end of the outer sleeve 5 is left with a first gap between it and the steel short sleeve 1, and the other end of the outer sleeve 5 is left with a second gap between it and the titanium alloy outer shell 8.

[0037] The first gap is 3mm and the second gap is 2mm.

[0038] In step S2, the support frame 6 includes a first frame 12 and a second frame 13. The first frame 12 is located below the first sleeve 3, and the second frame 13 is located below the second sleeve 4.

[0039] In step S3, there are four cylindrical rock columns 7, and the gap between any two adjacent cylindrical rock columns 7 is 1 mm.

[0040] Example 4 See Figure 1 A method for magnetic exploration of casing distance in downhole formations, comprising the following steps: S1. Fix the short steel sleeve 1 onto the bracket 2; S2. Connect the first sleeve 3 and the second sleeve 4 together by thread to form the outer sleeve 5, and then place the outer sleeve 5 on the support tube frame 6. S3. Process the collected rock blocks into multiple cylindrical rock columns 7, and push the cylindrical rock columns 7 into the outer casing 5; S4. Install a magnetic probe 9, a circuit board 10 and a battery 11 on the inner wall of the titanium alloy outer shell 8. The circuit board 10 is electrically connected to the battery 11 and the magnetic probe 9 is electrically connected to the circuit board 10. S5. Place the outer sleeve 5 between the steel short sleeve 1 and the titanium alloy outer shell 8, turn on the magnetic probe 9, and the magnetic probe 9 emits magnetic lines of force that pass through the cylindrical rock column 7 along the axial direction of the outer sleeve 5 until it touches the steel short sleeve 1.

[0041] In step S1, the length of the steel short sleeve 1 is 500mm.

[0042] In step S2, the length of the first sleeve 3 and the second sleeve 4 are both 7m, the outer diameter is 244.5mm, and the inner diameter is 224.4mm.

[0043] In step S5, placing the outer sleeve 5 between the steel short sleeve 1 and the titanium alloy outer shell 8 means that one end of the outer sleeve 5 is left with a first gap between it and the steel short sleeve 1, and the other end of the outer sleeve 5 is left with a second gap between it and the titanium alloy outer shell 8.

[0044] The first gap is 3mm and the second gap is 2mm.

[0045] More preferably, in step S2, the support frame 6 includes a first frame 12 and a second frame 13, with the first frame 12 located below the first sleeve 3 and the second frame 13 located below the second sleeve 4.

[0046] In step S3, there are four cylindrical rock columns 7, and the gap between any two adjacent cylindrical rock columns 7 is 2mm.

[0047] In step S3, the central axes of any two adjacent cylindrical rock columns 7 coincide.

[0048] In step S5, the magnetic probe 9 corresponds to the central axis of the cylindrical rock column 7.

[0049] Example 5 See Figure 1A downhole casing distance magnetic exploration system includes an outer casing 5 for placing a cylindrical rock column 7, a magnetic exploration tool, a short steel casing 1, a support frame 6, and a bracket 2. The short steel casing 1 is fixed on the bracket 2, and the outer casing 5 is fixed on the support frame 6. The outer casing 5 is located between the short steel casing 1 and the magnetic exploration tool. The magnetic exploration tool includes 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 to the battery 11, and the magnetic probe 9 is electrically connected to 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. The magnetic probe 9 corresponds to the central axis of the cylindrical rock column 7.

[0050] This embodiment is a preferred implementation method. The magnetic detection system can meet different production needs. Magnetic detection is simple and easy to promote.

[0051] The magnetic detection system has a simple overall structure, is easy to operate, and has good applicability.

[0052] The basic principle of this invention is as follows: In a non-magnetic environment on the ground, connect the ground rocks to form a rock wall of a certain length. Place a magnetic probe tool on one side of the rock wall and a short steel sleeve 1 on the other side of the rock wall. Activate the magnetic probe tool so that the magnetic lines emitted by the tool pass through the rock wall and reach the short steel sleeve 1, thus verifying the magnetic detection effect of the magnetic probe tool.

Claims

1. A method for magnetic exploration of casing distance in downhole rock formations, characterized in that, Includes the following steps: S1. Fix the short steel sleeve (1) onto the bracket (2); S2. Connect the first sleeve (3) and the second sleeve (4) together by thread to form an outer sleeve (5), and then place the outer sleeve (5) on the support tube rack (6); S3. Process the collected rock blocks into multiple cylindrical rock columns (7), and push the cylindrical rock columns (7) into the outer casing (5); S4. Install a magnetic probe (9), a circuit board (10) and a battery (11) on the inner wall of the titanium alloy shell (8). The circuit board (10) is electrically connected to the battery (11), and the magnetic probe (9) is electrically connected to the circuit board (10). S5. Place the outer sleeve (5) between the steel short sleeve (1) and the titanium alloy outer shell (8), turn on the magnetic probe (9), and the magnetic probe (9) emits magnetic lines of force along the axial direction of the outer sleeve (5) through the cylindrical rock column (7) until it touches the steel short sleeve (1).

2. The downhole casing distance magnetic exploration method according to claim 1, characterized in that: In step S1, the length of the steel short sleeve (1) is 500mm.

3. The downhole casing distance magnetic exploration method according to claim 1, characterized in that: In step S2, the length of the first sleeve (3) and the second sleeve (4) is 7m, the outer diameter is 244.5mm, and the inner diameter is 224.4mm.

4. The downhole casing distance magnetic exploration method according to claim 1, characterized in that: In step S5, placing the outer sleeve (5) between the steel short sleeve (1) and the titanium alloy outer shell (8) means that there is a first gap between one end of the outer sleeve (5) and the steel short sleeve (1), and a second gap between the other end of the outer sleeve (5) and the titanium alloy outer shell (8).

5. The downhole casing distance magnetic exploration method according to claim 1, characterized in that: The first gap is 2-3mm, and the second gap is 1-2mm.

6. The downhole casing distance magnetic exploration method according to claim 1, characterized in that: In step S2, the support tube frame (6) includes a first tube frame (12) and a second tube frame (13). The first tube frame (12) is located below the first sleeve (3), and the second tube frame (13) is located below the second sleeve (4).

7. The downhole casing distance magnetic exploration method according to claim 1, characterized in that: In step S3, there are four cylindrical rock columns (7), and the gap between any two adjacent cylindrical rock columns (7) is 1-2 mm.

8. The downhole casing distance magnetic exploration method according to claim 1, characterized in that: In step S3, the central axes of any two adjacent cylindrical rock columns (7) coincide.

9. The downhole casing distance magnetic exploration method according to claim 1, characterized in that: In step S5, the magnetic probe (9) corresponds to the central axis of the cylindrical rock column (7).

10. A downhole casing distance magnetic exploration system, comprising an outer casing (5) for placing a cylindrical rock column (7), characterized in that: It also includes a magnetic probing tool, a steel short sleeve (1), a support frame (6) and a bracket (2). The steel short sleeve (1) is fixed on the bracket (2), and the outer sleeve (5) is fixed on the support frame (6). The outer sleeve (5) is located between the steel short sleeve (1) and the magnetic probing tool. The magnetic probing tool includes 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 to the battery (11), and the magnetic probe (9) is electrically connected to 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). The magnetic probe (9) corresponds to the central axis of the cylindrical rock column (7).

Images