Performance detection method for underground packer

Abstract

The invention relates to the technical field of packer detection, in particular to a method for detecting the performance of an underground packer, which comprises the following steps of: coating a magnetic material and an inductor on an air sealing element in advance, and judging whether to mark a characterization packer or not according to the magnetic field intensity variation at the screened characterization packer position; the method comprises the following steps: determining a characteristic packing area and analyzing the magnetic field intensity variation of each key detection packer in the characteristic packing area to determine a performance attenuation dominant packer, pressurizing the performance attenuation dominant packer, and screening an anisotropic packer according to the magnetic field intensity variation difference before and after pressurizing, so as to improve the performance attenuation dominant packer. And the position coordinates of the isomerism packers are pre-warned and prompted, so that the calculation power consumption waste caused by unnecessary data entering a detection model is reduced, the packers with unstable performance are quickly and accurately positioned in a scene of cooperative work of a plurality of packers, and the detection efficiency of the packers is improved.

Description

Technical Field

[0001] The invention relates to the technical field of packer detection, and in particular to a performance detection method for a downhole packer. Background Art

[0002] Packers play a vital role in downhole operations, but the reliability of their performance directly affects the safety and efficiency of downhole operations. In order to separate different formation areas, prevent gas crossflow, and improve the production efficiency and stability of gas wells, packers are set at different locations. The coordinated work of multiple packers can better meet the needs of gas well production, but it also puts forward higher requirements on the performance detection and maintenance of packers. There are certain limitations in the performance detection methods of multiple downhole packers. Traditional detection methods are often not accurate and timely, and it is difficult to accurately judge the working status of each packer in a complex downhole environment. At the same time, existing detection methods may not be able to quickly locate packers with performance problems, resulting in untimely maintenance and replacement, which increases operational risks and costs. Therefore, a more efficient and accurate downhole packer performance detection method is needed to meet the needs of downhole operations.

[0003] For example, Chinese Patent Publication No.: CN104990672A, the invention discloses a method for testing the sealing performance of a packer rubber cartridge and a sealing performance testing device, the method for testing the sealing performance of a packer rubber cartridge comprises the following steps: Step 1: applying a radially inward sealing force to the packer rubber cartridge along the radial direction of the packer rubber cartridge, so that the packer rubber cartridge radially contracts and contacts with a drill pipe sleeved in the packer rubber cartridge; Step 2: setting a fluid at the contact point between the packer rubber cartridge and the drill pipe, and detecting the sealing performance between the packer rubber cartridge and the drill pipe by detecting the state of the fluid. The sealing performance of the shrinkable packer rubber cartridge can be effectively measured by the above method.

[0004] The prior art still has the following problems: The existing technology does not consider the scenario of multiple packers working together. Collecting data from the packers in the well one by one will generate a large amount of data transmission and processing requirements, which will bring a heavy burden to the detection system. The existing technology cannot classify massive data and call related data according to different detection purposes. It cannot jointly analyze the detection data with obvious representativeness, and cannot accurately locate the packers with unstable performance in the scenario of multiple packers working together, which affects the efficiency of packer detection. Summary of the invention

[0005] To this end, the present invention provides a performance detection method for a downhole packer to overcome the problems in the prior art that massive data cannot be classified and relevant data cannot be called according to different detection purposes, detection data with obvious representativeness cannot be jointly analyzed, and packers with unstable performance cannot be accurately located in a scenario where multiple packers work together.

[0006] To achieve the above object, the present invention provides a method for detecting the performance of a downhole packer, comprising: Pre-coating the air seal of each packer of the casing with magnetic material, and arranging a sensor at the edge of the sealing rubber tube of each packer to collect the magnetic field strength at the position of each packer; Generate a first information field and a second information field of the packer, and establish an association relationship between the first information field and the second information field, wherein the first information field includes the location coordinates of the packer, and the second information field includes the magnetic field strength collected by the sensor on the packer; In response to a number of packers being in a setting state, selecting a characterizing packer based on the first information field of each packer, and determining a change in magnetic field intensity within a preset time period according to a second information field associated with the characterizing packer to determine whether to mark the characterizing packer; Determine a characteristic isolation area based on the marked characterization packer, determine the packers in the characteristic isolation area as key detection packers, obtain the second information field of each key detection packer to analyze the change in magnetic field strength, so as to determine the performance attenuation dominant packer; The performance-attenuated dominant packer is pressurized to raise the hydraulic pressure inside the packer to a preset hydraulic pressure value, and the difference in magnetic field intensity change before and after pressurization is determined based on the second information field associated with each key detection packer in the characteristic isolation area where the performance-attenuated dominant packer is located, so as to screen the anomaly packers and issue an early warning prompt for the location coordinates of the anomaly packers.

[0007] Further, the process of screening and characterizing the packer includes: Determine the position coordinates of each packer based on the first information field of each packer; determining the spacing distance between the packers according to the position coordinates; Selecting packers whose spacing distance is greater than or equal to a first preset distance and less than a second preset distance as the characterized packers; Wherein, the first preset distance is smaller than the second preset distance.

[0008] Furthermore, the first preset distance and the second preset distance are determined according to the spacing distance between adjacent packers.

[0009] Furthermore, the second information field includes a magnetic field intensity component along the X-axis direction, a magnetic field intensity component along the Y-axis direction, and a magnetic field intensity component along the Z-axis direction collected by the sensor in a three-dimensional coordinate system based on the sensor.

[0010] Furthermore, the process of determining the change in magnetic field strength within a preset time period includes: Determine the change in the magnetic field intensity component along the X-axis direction within a preset time length, the change in the magnetic field intensity component along the Y-axis direction within a preset time length, and the change in the magnetic field intensity component along the Z-axis direction within a preset time length.

[0011] Furthermore, a magnetic field intensity change characterization coefficient is calculated based on the magnetic field intensity change, wherein the magnetic field intensity change characterization coefficient is positively correlated with the change in the axial magnetic field intensity component and the change in the radial magnetic field intensity component, the change in the radial magnetic field intensity component is determined according to the change in the magnetic field intensity component along the X-axis direction and the change in the magnetic field intensity component along the Y-axis direction, and the change in the axial magnetic field intensity component is determined according to the change in the magnetic field intensity component along the Z-axis direction.

[0012] Further, the process of determining whether to mark the characterizing packer includes: Comparing the magnetic field intensity variation characterization coefficient with a preset magnetic field intensity variation characterization coefficient threshold; If the magnetic field intensity variation characterization coefficient is greater than the magnetic field intensity variation characterization coefficient threshold, it is determined that the characterization packer is marked.

[0013] Furthermore, the characteristic isolation area is an area to be marked within a preset distance range with the packer as the center reference.

[0014] Further, the process of determining a performance-degrading dominant packer includes: Determine the maximum change of the magnetic field intensity component along the X-axis direction, the maximum change of the magnetic field intensity component along the Y-axis direction, and the maximum change of the magnetic field intensity component along the Z-axis direction of each key detection packer within a preset time length; The key detection packer corresponding to the maximum value of the maximum change amount is determined as the performance-attenuated dominant packer.

[0015] Furthermore, the difference in magnetic field intensity change is determined based on the difference between an average value of magnetic field intensity change of each key detection packer within a preset time period before pressurization and an average value of magnetic field intensity change within a preset time period after pressurization.

[0016] Furthermore, the process of determining the average value of the change in magnetic field strength within a preset time period before boosting includes: Calculate the average value of the change in the magnetic field intensity component along the X-axis direction, the change in the magnetic field intensity component along the Y-axis direction and the change in the magnetic field intensity component along the Z-axis direction of the key detection seal within the preset time before pressurization, and determine the average value as the average value of the magnetic field intensity change of the key detection seal within the preset time before pressurization.

[0017] Furthermore, the process of determining the average value of the change in magnetic field strength within a preset time after the boost includes: Calculate the average value of the change in the magnetic field intensity component along the X-axis direction, the change in the magnetic field intensity component along the Y-axis direction and the change in the magnetic field intensity component along the Z-axis direction of the key detection seal within the preset time after pressurization, and determine the average value as the average value of the magnetic field intensity change of the key detection seal within the preset time after pressurization.

[0018] Furthermore, the process of screening heterogeneous packers includes: Determine the minimum difference value according to the difference between the average value of the change in magnetic field intensity of each key detection packer within a preset time before pressurization and the average value of the change in magnetic field intensity within a preset time after pressurization; The key detection packer corresponding to the minimum difference value is screened as the heterogeneous packer.

[0019] Furthermore, the process of determining the position coordinates of the heterogeneous packer includes: Establishing a three-dimensional coordinate system with the location of the wellhead where the casing is located as the origin; The position coordinates of each packer are determined based on the three-dimensional coordinate system, and an early warning prompt is given to the position coordinates of the anisotropic packer in the three-dimensional coordinate system.

[0020] Furthermore, the performance-attenuation dominant packer is pressurized by increasing the hydraulic pressure to the central pipe of the performance-attenuation dominant packer.

[0021] Compared with the prior art, the beneficial effect of the present invention lies in that, by pre-coating magnetic material on the air seal and setting sensors, the present invention selects and characterizes the packers through the first information field of each packer, determines the change in magnetic field strength within a preset time period according to the second information field associated with the characterizing packer to determine whether to mark the characterizing packer, determines the characteristic isolation area and analyzes the change in magnetic field strength of the second information field of each key detection packer in the characteristic isolation area to determine the performance-attenuated explicit packer, pressurizes the performance-attenuated explicit packer, selects the anomaly packers according to the difference in magnetic field intensity change before and after pressurization, and issues early warning prompts for the location coordinates of the anomaly packers, thereby achieving the classification of massive data and calling related data according to different detection purposes, and by jointly analyzing the detection data with obvious characterization, quickly and accurately locates the unstable performance packers in the scenario where multiple packers work together, thereby improving the efficiency of packer detection.

[0022] In particular, the present invention detects performance differences of the packers by collecting changes in magnetic field intensity by coating magnetic material on the air seal and arranging sensors on the edge of the sealing rubber tube. Those skilled in the art will understand that when the packer is in a stable seated state, the relative positions of the sealing rubber tube and the air seal are fixed. In a scenario where multiple packers work together, pressures in different areas affect each other due to packers with poor sealing performance, and pressure fluctuations are transmitted along the tubing. When the pressure fluctuation is large, the tubing may be displaced in the well, that is, the tubing may creep, resulting in changes in the relative positions of the sealing rubber tube and the air seal in the seated state. The present invention achieves detection of tiny displacements of the packer in the seated state by coating magnetic material on the air seal and arranging sensors on the edge of the sealing rubber tube, thereby providing reliable data for subsequent performance testing.

[0023] In particular, the present invention realizes effective classification of massive data by generating the first information field and the second information field of the packer and establishing an associative relationship. Relevant data can be conveniently called according to different detection purposes. When screening and characterizing the packers, the position coordinates are determined based on the first information field, and the spacing distance between the packers is determined. When analyzing the change in magnetic field strength, the magnetic field strength data in the second information field is called for analysis. Furthermore, the massive data can be classified and relevant data can be called according to different detection purposes, thereby improving the efficiency of packer detection.

[0024] In particular, the present invention selects representative packers by screening the packers with spacing distances within a specific range. In actual situations, when performing preliminary inspections on a number of packers, it is necessary to ensure that the received data content can satisfy the comprehensive inspection of all areas downhole. The present invention establishes a coordinate system to read the coordinate position of each packer, screens out a number of packers at a reasonable spatial distance according to the distribution of each packer on the coordinate axis, and receives data from the information field of the data field of the corresponding sensor. As a result, the increase in computing power consumption caused by a large amount of data entering the analysis system at the same time and the waste of computing power consumption caused by unnecessary data entering the analysis system are greatly reduced, thereby improving the efficiency of packer detection.

[0025] In particular, the present invention calculates the magnetic field intensity change characterization coefficient by the change of the magnetic field intensity component along the X, Y, and Z axis directions in the three-dimensional coordinate system. Those skilled in the art can understand that the tubing creep experienced by the packer is divided into radial creep and axial creep, and the radial creep and axial creep of the tubing in a complex downhole working environment are variable. The present invention characterizes the radial creep state of the tubing by the change of the magnetic field intensity component along the X and Y axis directions, and characterizes the axial creep state of the tubing by the change of the magnetic field intensity component along the Z axis direction. This makes the analysis of the magnetic field intensity change more comprehensive and accurate, realizes the joint analysis of detection data with obvious characterization, and improves the efficiency of packer detection.

[0026] In particular, the present invention pressurizes the packers with obvious performance attenuation, and screens the anomaly packers according to the difference in magnetic field intensity changes of the key detection packers in the characteristic isolation area before and after the pressurization. In this way, the packers with unstable performance can be further determined, and the coordinates of their positions can be warned. The position coordinates of the packers can be determined more accurately, and accurate position information can be provided for maintenance and replacement. This enables the rapid and precise positioning of unstable performance packers in the scenario where multiple packers work together, thereby improving the efficiency of packer detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A step diagram of a method for detecting the performance of a downhole packer according to an embodiment of the present invention; Figure 2 A schematic diagram of the internal structure of a packer according to an embodiment of the present invention; Figure 3 A diagram of the steps for selecting and characterizing a packer according to an embodiment of the present invention; Figure 4 A logic flow chart for determining whether to mark a characteristic packer according to an embodiment of the present invention; In the figure, a central tube 1, a sealing rubber cylinder 2, an upper piston 3, a connecting pin 4, a gas sealing member 5, a pressure-conducting hole 6, an upper pressure cover 7, a lower pressure cover 8, a fixed piston 9, a piston block 10, a piston sleeve 11, and a sensor 12 are provided. DETAILED DESCRIPTION

[0028] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0030] It should be noted that, in the description of the present invention, terms such as "upper", "lower", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0031] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] See also Figures 1 to 3 As shown, Figure 1 This is a step diagram of a method for detecting the performance of a downhole packer according to an embodiment of the present invention. Figure 2 The internal structure diagram of the packer of the embodiment of the present invention is shown in FIG. 1 ; the performance detection method of the downhole packer of the present invention comprises: Step S10, pre-coating the magnetic material on the air seal 5 of each packer of the casing, and setting a sensor 12 on the edge of the sealing rubber tube 2 of each packer for collecting the magnetic field strength at the position of each packer; Step S20, generating a first information field and a second information field of the packer, and establishing an association relationship between the first information field and the second information field, wherein the first information field includes the position coordinates of the packer, and the second information field includes the magnetic field strength collected by the sensor 12 on the packer; Step S30, in response to a plurality of packers being in a setting state, selecting a characteristic packer based on the first information field of each packer, and determining a change in magnetic field intensity within a preset time period according to a second information field associated with the characteristic packer to determine whether to mark the characteristic packer; Step S40, determining a characteristic isolation area based on the marked characterization packer, determining the packers in the characteristic isolation area as key detection packers, obtaining the second information field of each key detection packer to analyze the change in magnetic field strength, so as to determine the performance attenuation dominant packer; Step S50, pressurizing the performance-attenuating dominant packer to increase the hydraulic pressure value inside the packer to a preset hydraulic pressure value, and determining the difference in magnetic field intensity change before and after pressurization based on the second information field associated with each key detection packer in the characteristic isolation area where the performance-attenuating dominant packer is located, so as to screen the anisotropic packers and issue an early warning prompt for the location coordinates of the anisotropic packers.

[0033] For more details, please refer to Figure 2 as well as Figure 3 As shown, during the sealing process of the packer, hydraulic pressure is applied to the center tube 1 of the packer, and the hydraulic pressure enters between the upper piston 3 and the fixed piston 9 from the pressure guide hole 6 of the center tube 1. The air seal 5 expands to achieve an air sealing effect. The upper pressure cover 7 begins to move upward under the action of the hydraulic pressure and pushes the upper piston 3 to move upward. At the same time, the upper piston 3 drives the piston sleeve 11 to move upward together through the connecting pin 4, and squeezes the sealing rubber cylinder 2 to expand in the radial direction to achieve the sealing of the packer. During this process, the lower pressure cover 8, the fixed piston 9, and the piston block 10 play a role in limiting the movement stroke of the upper piston 3 during the sealing process, provide support and fixation for the entire packer, and ensure the stability of the packer during the sealing process. The working principle of the packer can be understood by those skilled in the art and will not be repeated here.

[0034] According to the working principle of the seal, the present invention places a permanent magnet in the air seal 5 so that the position where the air seal 5 is located exhibits the characteristics of a magnet and generates a certain magnetic field strength, and sets a sensor 12 at the edge of the sealing rubber tube 2, so that when the seal is in the sealing state, if the seal is good and the pipe string does not creep, the relative position between the sensor 12 and the air seal coated with the magnetic material remains basically unchanged, and the magnetic field strength detected by the sensor 12 is also relatively stable. If the seal of the seal deteriorates, causing the pipe string to creep, the relative position between the permanent magnet and the sensor 12 at the edge of the sealing rubber tube 2 will change. This position change will cause the magnetic field strength detected by the sensor 12 to change. For example, when the pipe string creeps axially or radially, the distance between the sensor 12 and the magnet may increase or decrease, thereby causing the magnetic field strength to change.

[0035] Specifically, the gas seal 5 of the packer may be coated with a magnetic material to make the gas seal magnetic. Coating a magnetic material on the surface of a metal structure is a prior art and will not be described in detail here.

[0036] Specifically, the present invention does not limit the structure of the sensor 12. In the prior art, common sensors 12 for magnetic field strength include magnetoresistors and Hall sensors, etc., which only need to be able to measure the strength and direction of the magnetic field, and will not be elaborated here.

[0037] Specifically, the present invention detects the performance difference of the packer by coating magnetic material on the air seal 5 and arranging a sensor 12 on the edge of the sealing rubber tube 2, and collecting the change of magnetic field intensity. It can be understood by those skilled in the art that when the packer is in a stable sealing state, the relative positions of the sealing rubber tube 2 and the air seal 5 are fixed. In a scenario where multiple packers work together, the pressures in different areas affect each other due to the poor sealing performance of the packer, and the pressure fluctuations are transmitted along the tubing. When the pressure fluctuations are large, the tubing may be displaced in the well, that is, the tubing may creep, resulting in a change in the relative position of the sealing rubber tube 2 and the air seal 5 in the sealing state. The present invention realizes the detection of tiny displacements of the packer in the sealing state by coating magnetic material on the air seal 5 and arranging a sensor 12 on the edge of the sealing rubber tube 2, thereby providing reliable data for subsequent performance testing.

[0038] Specifically, the present invention realizes effective classification of massive data by generating the first information field and the second information field of the packer and establishing an associative relationship. It can conveniently call relevant data according to different detection purposes. When screening and characterizing the packers, the position coordinates are determined according to the first information field, and the spacing distance between the packers is determined. When analyzing the change in magnetic field strength, the magnetic field strength data in the second information field is called for analysis. Furthermore, it is possible to classify massive data and call relevant data according to different detection purposes, thereby improving the efficiency of packer detection.

[0039] Specifically, see Figure 3 As shown, it is a step diagram of screening and characterizing the packer according to an embodiment of the present invention. The process of screening and characterizing the packer includes: Step S301, determining the position coordinates of each packer based on the first information field of each packer; Step S302, determining the spacing distance between the packers according to the position coordinates; Step S303, selecting the packers whose spacing distance is greater than or equal to the first preset distance and less than the second preset distance as the characterized packers; Wherein, the first preset distance is smaller than the second preset distance.

[0040] Specifically, the present invention selects representative packers by screening the packers with spacing distances within a specific range. In actual situations, when performing preliminary inspections on a number of packers, it is necessary to ensure that the received data content can satisfy the comprehensive inspection of all areas downhole. The present invention establishes a coordinate system to read the coordinate position of each packer, screens out a number of packers at a reasonable spatial distance according to the distribution of each packer on the coordinate axis, and receives the data of the information field of the data field of the corresponding sensor 12. As a result, the increase in computing power consumption caused by a large amount of data entering the analysis system at the same time and the waste of computing power caused by unnecessary data entering the analysis system are greatly reduced, thereby improving the efficiency of packer detection.

[0041] Specifically, the first preset distance D1 and the second preset distance D2 are determined according to the spacing distance between adjacent packers.

[0042] Preferably, the average value D of the spacing distances between several adjacent packers can be calculated in advance. av The values ​​of the first preset distance D1 and the second preset distance D2 can be set by those skilled in the art according to the data volume requirement of the preliminary detection. The smaller the values ​​of the first preset distance D1 and the second preset distance D2 are, the more data representing the packer screened by the preliminary detection is. Preferably, the first preset distance D1 can be set to 2×D av , the second preset distance D2=5×D av .

[0043] Specifically, the second information field includes the magnetic field intensity component H along the X-axis direction collected by the sensor 12 in the three-dimensional coordinate system based on the sensor 12. X , the magnetic field intensity component H along the Y axis Y And the magnetic field intensity component H along the Z axis Z .

[0044] Specifically, the process of determining the change in magnetic field strength within a preset time period includes: Determine the change H of the magnetic field intensity component along the X-axis direction within a preset time length X1 , the change in the magnetic field intensity component along the Y axis within the preset time length H Y1 And the change H of the magnetic field intensity component along the Z axis within the preset time length Z1 .

[0045] Specifically, the preset time length for detecting the change in the magnetic field intensity component can be set according to the detection accuracy requirements and the detection efficiency. The longer the preset time length, the more data on the change in the magnetic field intensity component is collected, and the slower the calculation efficiency. Preferably, the preset time length can be set in the range of [10,30], with the interval unit being min.

[0046] Specifically, a magnetic field intensity change characterization coefficient is calculated based on the magnetic field intensity change, wherein the magnetic field intensity change characterization coefficient is positively correlated with the change of the axial magnetic field intensity component and the change of the radial magnetic field intensity component, the change of the radial magnetic field intensity component is determined according to the change of the magnetic field intensity component along the X-axis direction and the change of the magnetic field intensity component along the Y-axis direction, and the change of the axial magnetic field intensity component is determined according to the change of the magnetic field intensity component along the Z-axis direction.

[0047] The formula for calculating the characterization coefficient of the magnetic field intensity change is:

[0048] Among them, Q is the coefficient representing the change of magnetic field intensity, H X1 is the change in magnetic field intensity along the X-axis direction, H Y1 is the change in magnetic field intensity along the Y axis, H Z1 is the change in the magnetic field intensity component along the Z-axis direction, H0 is the preset reference value of the change in the magnetic field intensity component, α is the weight coefficient of the magnetic field intensity component along the X-axis direction, β is the weight coefficient of the magnetic field intensity component along the Y-axis direction, and e is a constant.

[0049] The preset reference value H0 for the change in the magnetic field intensity component can be obtained based on pre-tests and calculations. The average value of the change in the magnetic field intensity component along the X-axis, Y-axis and Z-axis directions of the packer in a stable sealing state due to interference factors such as the environment is pre-calculated for several times, and the calculated average value is determined as the reference value H0 for the change in the magnetic field intensity component. Preferably, the reference value H0 for the change in the magnetic field intensity component ranges from [100,500], and the interval unit is μT.

[0050] The weight coefficient α of the magnetic field intensity component along the X-axis direction and the weight coefficient β of the magnetic field intensity component along the Y-axis direction are selected by technical personnel in this field according to the degree of influence of the magnetic field intensity component along the X-axis direction and the magnetic field intensity along the Y-axis direction on the calculation results in historical data. α+β=1, the demolding process duration weight coefficient α=0.5, and the interval distance weight coefficient β=0.5 can be set.

[0051] Specifically, the present invention calculates the magnetic field intensity change characterization coefficient by the change of the magnetic field intensity component along the X, Y, and Z axis directions in the three-dimensional coordinate system. Those skilled in the art can understand that the tubing creep experienced by the isolation device is divided into radial creep and axial creep, and the radial creep and axial creep of the tubing in a complex downhole working environment are variable. The present invention characterizes the radial creep state of the tubing by the change of the magnetic field intensity component along the X and Y axis directions, and characterizes the axial creep state of the tubing by the change of the magnetic field intensity component along the Z axis direction. This makes the analysis of the magnetic field intensity change more comprehensive and accurate, realizes the joint analysis of detection data with obvious characterization, and improves the efficiency of isolation device detection.

[0052] Specifically, see Figure 4 As shown, it is a logic flow chart of determining whether to mark the characterizing packer according to an embodiment of the present invention. The process of determining whether to mark the characterizing packer includes: Comparing the magnetic field intensity variation characterization coefficient Q with a preset magnetic field intensity variation characterization coefficient threshold value Q0; If the magnetic field intensity variation characterization coefficient Q is less than or equal to the magnetic field intensity variation characterization coefficient threshold value Q0, it is determined that the characterization packer is not marked; If the magnetic field intensity variation characterizing coefficient Q is greater than the magnetic field intensity variation characterizing coefficient threshold value Q0, it is determined that the characterizing packer is marked.

[0053] Specifically, the larger the value of the preset magnetic field intensity change coefficient threshold Q0, the greater the change in magnetic induction intensity at the location of the marked seal. Technical personnel in this field can set the magnetic field intensity change coefficient threshold according to this setting logic. Preferably, the value range of the magnetic field intensity change coefficient threshold Q0 is [4.18, 4.28].

[0054] Specifically, the characteristic isolation area is an area to be marked that has a preset distance range with the packer as the center reference.

[0055] Specifically, the process of determining a degradation-dominant packer includes: Determine the maximum change H of the magnetic field intensity component along the X-axis direction of each key detection packer within the preset time length Xm , the maximum change of the magnetic field intensity component along the Y-axis direction H Ym And the maximum change of the magnetic field intensity component along the Z axis direction H Zm ; The key detection packer corresponding to the maximum value of the maximum change amount is determined as the performance-attenuated dominant packer.

[0056] For example, the maximum change in the magnetic field intensity component along the X-axis direction H Xm , the maximum change of the magnetic field intensity component along the Y-axis direction H Ym And the maximum change of the magnetic field intensity component along the Z axis direction H Zm For comparison, if H Zm >H Xm >H Ym , then H Zm The corresponding key detection packer is determined to be a performance-degradation dominant packer.

[0057] Specifically, the difference in magnetic field intensity change is based on the average value H of the magnetic field intensity change of each key detection packer within a preset time before pressurization. av The average value of the magnetic field intensity change within the preset time after boosting H av 'The difference is determined.

[0058] Specifically, the process of determining the average value of the change in magnetic field strength within a preset time before boosting includes: Calculate the change amount of the magnetic field intensity component along the X-axis direction, the change amount of the magnetic field intensity component along the Y-axis direction and the change amount of the magnetic field intensity component along the Z-axis direction of the key detection packer within the preset time length before pressurization, and determine the average value as the average value H of the magnetic field intensity change of the key detection packer within the preset time length before pressurization av .

[0059] Specifically, the process of determining the average value of the change in magnetic field strength within a preset time after boosting includes: Calculate the average value of the change in the magnetic field intensity component along the X-axis direction, the change in the magnetic field intensity component along the Y-axis direction, and the change in the magnetic field intensity component along the Z-axis direction of the key detection packer within the preset time after pressurization, and determine the average value as the average value H of the magnetic field intensity change of the key detection packer within the preset time after pressurization av '.

[0060] Specifically, the process of screening heterogeneous packers includes: According to the average value H of the magnetic field intensity change of each key detection packer within the preset time before pressurization av The average value of the magnetic field intensity change within the preset time after boosting H av 'The difference determines the minimum difference; The key detection packer corresponding to the minimum difference value is screened as the heterogeneous packer.

[0061] Specifically, the process of determining the position coordinates of the heterogeneous packer includes: Establishing a three-dimensional coordinate system with the location of the wellhead where the casing is located as the origin; The position coordinates of each packer are determined based on the three-dimensional coordinate system, and an early warning prompt is given to the position coordinates of the anisotropic packer in the three-dimensional coordinate system.

[0062] Specifically, the present invention pressurizes the packers with obvious performance attenuation, and screens the anomaly packers according to the difference in magnetic field intensity changes of the key detection packers in the characteristic isolation area before and after the pressurization. In this way, the packers with unstable performance can be further determined, and the coordinates of their positions can be warned. The position coordinates of the packers can be determined more accurately, and accurate position information can be provided for maintenance and replacement. This enables the rapid and precise positioning of unstable performance packers in the scenario where multiple packers work together, thereby improving the efficiency of packer detection.

[0063] Specifically, the performance-attenuation dominant packer is pressurized by increasing the hydraulic pressure to the central pipe 1 of the performance-attenuation dominant packer.

[0064] It can be understood that the preset hydraulic value P1 after the hydraulic value inside the performance-attenuated explicit packer is pressurized can be set according to the initial hydraulic value P0 inside the packer, wherein P1=ε×P0, ε is the pressurization factor of the preset hydraulic value, and the value range of ε is [1.05,1.1].

[0065] It can be understood by those skilled in the art that when hydraulic oil or other liquid is pressed into the central pipe 1 of the packer, as the hydraulic pressure gradually increases, the sealing rubber tube 2 and other components of the packer will be subjected to extrusion pressure, thereby making the fit between the packer and the wall of the pipe string closer, thereby enhancing the sealing effect. This is the prior art and will not be elaborated here.

[0066] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for detecting performance of a downhole packer, characterized in that: include: Pre-coating the air seal of each packer of the casing with magnetic material, and arranging a sensor at the edge of the sealing rubber tube of each packer to collect the magnetic field strength at the position of each packer; Generate a first information field and a second information field of the packer, and establish an association relationship between the first information field and the second information field, wherein the first information field includes the location coordinates of the packer, and the second information field includes the magnetic field strength collected by the sensor on the packer; In response to a number of packers being in a setting state, selecting a characterizing packer based on the first information field of each packer, and determining a change in magnetic field intensity within a preset time period according to a second information field associated with the characterizing packer to determine whether to mark the characterizing packer; Determine a characteristic isolation area based on the marked characterization packer, determine the packers in the characteristic isolation area as key detection packers, obtain the second information field of each key detection packer to analyze the change in magnetic field strength, so as to determine the performance attenuation dominant packer; The performance-attenuated dominant packer is pressurized to raise the hydraulic pressure inside the packer to a preset hydraulic pressure value, and the difference in magnetic field intensity change before and after pressurization is determined based on the second information field associated with each key detection packer in the characteristic isolation area where the performance-attenuated dominant packer is located, so as to screen the anomaly packers and issue an early warning prompt for the location coordinates of the anomaly packers.

2. The performance detection method of a downhole packer according to claim 1, characterized in that: The process of screening and characterizing packers includes: Determine the position coordinates of each packer based on the first information field of each packer; determining the spacing distance between the packers according to the position coordinates; Selecting packers whose spacing distance is greater than or equal to a first preset distance and less than a second preset distance as the characterized packers; Wherein, the first preset distance is smaller than the second preset distance.

3. The performance detection method of a downhole packer according to claim 2, characterized in that: The first preset distance and the second preset distance are determined according to the spacing distance between adjacent packers.

4. The performance detection method of a downhole packer according to claim 1, characterized in that: The second information field includes a magnetic field intensity component along an X-axis direction, a magnetic field intensity component along a Y-axis direction, and a magnetic field intensity component along a Z-axis direction collected by the sensor in a three-dimensional coordinate system based on the sensor.

5. The performance detection method of a downhole packer according to claim 4, characterized in that: The process of determining the change in magnetic field strength within a preset time period includes: Determine the change in the magnetic field intensity component along the X-axis direction within a preset time length, the change in the magnetic field intensity component along the Y-axis direction within a preset time length, and the change in the magnetic field intensity component along the Z-axis direction within a preset time length.

6. The performance detection method of a downhole packer according to claim 5, characterized in that: A magnetic field intensity change coefficient is calculated based on the magnetic field intensity change, wherein the magnetic field intensity change coefficient is positively correlated with the change of the axial magnetic field intensity component and the change of the radial magnetic field intensity component, the change of the radial magnetic field intensity component is determined according to the change of the magnetic field intensity component along the X-axis direction and the change of the magnetic field intensity component along the Y-axis direction, and the change of the axial magnetic field intensity component is determined according to the change of the magnetic field intensity component along the Z-axis direction.

7. The method for detecting the performance of a downhole packer according to claim 6, characterized in that: The process of determining whether to mark the characterizing packer includes: Comparing the magnetic field intensity variation characterization coefficient with a preset magnetic field intensity variation characterization coefficient threshold; If the magnetic field intensity variation characterization coefficient is greater than the magnetic field intensity variation characterization coefficient threshold, it is determined that the characterization packer is marked.

8. The method for detecting the performance of a downhole packer according to claim 7, characterized in that: The characteristic isolation area is an area to be marked that has a preset distance range with the packer as the center reference.

9. The method for detecting the performance of a downhole packer according to claim 8, characterized in that: The process for determining a degradation-dominant packer includes: Determine the maximum change of the magnetic field intensity component along the X-axis direction, the maximum change of the magnetic field intensity component along the Y-axis direction, and the maximum change of the magnetic field intensity component along the Z-axis direction of each key detection packer within a preset time length; The key detection packer corresponding to the maximum value of the maximum change amount is determined as the performance-attenuated dominant packer.

10. The method for detecting the performance of a downhole packer according to claim 9, characterized in that: The difference in magnetic field intensity change is determined based on the difference between the average value of magnetic field intensity change of each key detection packer within a preset time period before pressurization and the average value of magnetic field intensity change within a preset time period after pressurization.

11. The method for detecting the performance of a downhole packer according to claim 10, characterized in that: The process of determining the average value of the change in magnetic field strength within a preset time period before boosting includes: Calculate the average value of the change in the magnetic field intensity component along the X-axis direction, the change in the magnetic field intensity component along the Y-axis direction and the change in the magnetic field intensity component along the Z-axis direction of the key detection seal within the preset time before pressurization, and determine the average value as the average value of the magnetic field intensity change of the key detection seal within the preset time before pressurization.

12. The method for detecting the performance of a downhole packer according to claim 10, characterized in that: The process of determining the average value of the change in magnetic field strength within a preset time after boosting includes: Calculate the average value of the change in the magnetic field intensity component along the X-axis direction, the change in the magnetic field intensity component along the Y-axis direction and the change in the magnetic field intensity component along the Z-axis direction of the key detection seal within the preset time after pressurization, and determine the average value as the average value of the magnetic field intensity change of the key detection seal within the preset time after pressurization.

13. The method for detecting the performance of a downhole packer according to claim 10, characterized in that: The process of selecting heterogeneous packers includes: Determine the minimum difference value according to the difference between the average value of the change in magnetic field intensity of each key detection packer within a preset time before pressurization and the average value of the change in magnetic field intensity within a preset time after pressurization; The key detection packer corresponding to the minimum difference value is screened as the heterogeneous packer.

14. The method for detecting the performance of a downhole packer according to claim 1, characterized in that: The process of determining the position coordinates of the heterogeneous packer includes: Establishing a three-dimensional coordinate system with the location of the wellhead where the casing is located as the origin; The position coordinates of each packer are determined based on the three-dimensional coordinate system, and an early warning prompt is given to the position coordinates of the anisotropic packer in the three-dimensional coordinate system.

15. The method for detecting the performance of a downhole packer according to claim 1, characterized in that: The performance-attenuation dominant packer is pressurized by increasing the hydraulic pressure to the central pipe of the performance-attenuation dominant packer.

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