Process method for repairing oil-water well pipe sleeve

Abstract

The invention discloses a process method for repairing a pipe sleeve of an oil-water well, and the process method for repairing the pipe sleeve of the oil-water well comprises the steps that the hole shrinkage position in the pipe sleeve and the hole shrinkage rate of the pipe sleeve are obtained, and the hole shrinkage rate is obtained by calculating the deformation inner diameter of the pipe sleeve after deformation and the initial inner diameter of the pipe sleeve before deformation. And when the hole shrinkage rate is smaller than or equal to a preset value, the pipe sleeve is repaired at the hole shrinkage position through a shaping process. And after the pipe sleeve is repaired through the shaping process, the repaired inner diameter of the pipe sleeve is obtained. Judging whether the difference between the repaired inner diameter and the initial inner diameter is smaller than or equal to the first distance or not; and when the difference value between the repaired inner diameter and the initial inner diameter is smaller than or equal to the first distance, the pipe sleeve is repaired through the pipe expansion technology. Due to the fact that the expansion pipe technology utilizes the expansion pipe patching technology, the pipe sleeve can be supported by the expansion pipe at the reshaping technology repairing position of the pipe sleeve, the pipe sleeve can be prevented from reducing again at the reshaping technology repairing position, the stability of the pipe sleeve is improved, and it is guaranteed that the repairing effect of the pipe sleeve meets the production requirement of an oil-water well.

Description

Technical Field

[0001] The present application belongs to the technical field of oil and water well casing repair, and specifically relates to a process method for repairing oil and water well casing. Background Art

[0002] As oilfield development reaches the middle and late stages, more and more oil and water well casings are damaged. Casing repair is a special repair technology for oil and water wells with damaged casings, and is also an important means to restore normal production of oil and water wells.

[0003] In the related art, due to the limitation of casing repair technology, repairing a severely shrunken casing using conventional casing repair technology is prone to accidents such as casing window opening or casing rebound, resulting in poor casing repair effect that cannot meet the production needs of oil and water wells. Summary of the invention

[0004] In order to solve the technical problem that the repair effect of the sleeve in the related art is poor and cannot meet the production needs of oil and water wells, the present application provides a process method for repairing the casing of an oil and water well, and the process method for repairing the casing of an oil and water well includes:

[0005] Obtaining a reduced diameter position in the sleeve and a reduced diameter rate of the sleeve, wherein the reduced diameter rate is calculated based on a deformed inner diameter of the sleeve after deformation and an initial inner diameter of the sleeve before deformation;

[0006] When the reduction ratio is less than or equal to a preset value, a shaping process is used to repair the sleeve at the reduction position;

[0007] After the sleeve is repaired by the shaping process, a repaired inner diameter of the sleeve is obtained;

[0008] Determining whether the difference between the repaired inner diameter and the initial inner diameter is less than or equal to a first distance;

[0009] When the difference between the repair inner diameter and the initial inner diameter is less than or equal to the first distance, the pipe sleeve is repaired by using an expansion pipe process.

[0010] In some embodiments, the process for repairing oil and water well casing further includes:

[0011] When the difference between the repaired inner diameter and the initial inner diameter is greater than the first distance, determining whether the difference between the repaired inner diameter and the initial inner diameter and the first distance is less than or equal to a second distance;

[0012] When the difference between the repaired inner diameter and the initial inner diameter and the difference between the first distance and the second distance is greater than the second distance, the sleeve is repaired by the shaping process;

[0013] When the difference between the repaired inner diameter and the initial inner diameter and the difference between the first distance is less than or equal to the second distance, the sleeve is repaired by a milling process.

[0014] In some embodiments, before obtaining the reduced diameter position in the sleeve and the reduced diameter rate of the sleeve, the method further includes:

[0015] A well washing and pressure reducing operation is performed on the pipe casing, wherein the well washing and pressure reducing operation includes cleaning the inner wall of the pipe casing.

[0016] In some embodiments, after performing the well washing and pressure operation on the casing and before obtaining the reduced diameter position in the casing and the reduced diameter rate of the casing, the method further includes:

[0017] The reduced diameter position in the sleeve, the deformed inner diameter of the sleeve after deformation, and the initial inner diameter of the sleeve before deformation are measured.

[0018] In some embodiments, the shaping construction pipe string used in the shaping process includes a shaping pipe string, a first expansion head and a weight indicator, wherein the first expansion head and the weight indicator are respectively connected to the shaping pipe string; the shaping process includes:

[0019] Lowering the first expansion head along the extension direction of the sleeve to the reduced diameter position;

[0020] Continue to lower the first expansion head until the weight indicator shows zero;

[0021] The shaping construction pipe string is pressed until the first expansion head can pass through the reduced diameter position.

[0022] In some embodiments, a plurality of rolling balls are disposed on the circumference of the first expanding head, and the rolling balls are convexly disposed on the circumference of the first expanding head and are rotatably connected to the first expanding head; lowering the first expanding head to the reduced diameter position along the extension direction of the sleeve includes:

[0023] Put the first expansion head into the sleeve so that the rolling ball is slidably connected with the inner wall of the sleeve;

[0024] The first expansion head is lowered to the reduced diameter position along the extension direction of the sleeve.

[0025] In some embodiments, the step of pressing the shaping construction pipe string until the first expansion head can pass through the reduced diameter position includes:

[0026] Applying a first pressure to the shaping construction pipe string, lowering the first expansion head until the indicator weight meter shows zero;

[0027] The second pressure is applied to the shaping construction pipe string for multiple times until the first expansion head passes through the reduced diameter position.

[0028] In some embodiments, after lowering the first expansion head to the reduced diameter position along the extension direction of the sleeve, the method further includes:

[0029] The first bulging head is replaced with a second bulging head, wherein the difference between the outer diameter of the second bulging head and the outer diameter of the first bulging head is greater than or equal to a preset outer diameter difference;

[0030] Lowering the second expansion head along the extension direction of the sleeve to the reduced diameter position;

[0031] Continue to lower the second expansion head until the weight indicator shows zero;

[0032] The shaping construction pipe string is pressed until the second expansion head passes through the reduced diameter position.

[0033] In some embodiments, the expansion pipe process uses an expansion construction pipe string including an expansion pipe string and a weight indicator connected to the expansion pipe string, and the expansion pipe process includes:

[0034] Lowering the expansion pipe string to the reduced diameter position;

[0035] The expansion pipe string is pressurized to expand the expansion pipe string until the expansion pipe fits the inner wall of the pipe sleeve.

[0036] In some embodiments, the step of pressing the shaping construction pipe string until the second expansion head passes through the reduced diameter position further includes:

[0037] Determine whether the expansion string can be lifted and started;

[0038] If not, increase the auxiliary lifting load of the expansion pipe string or reduce the thickness of the expansion pipe.

[0039] According to the process method for repairing the casing of an oil and water well provided by one or more embodiments of the present application, the process method for repairing the casing of an oil and water well includes obtaining the reduced diameter position in the casing and the reduced diameter rate of the casing, wherein the reduced diameter rate is calculated by the deformed inner diameter of the casing after deformation and the initial inner diameter of the casing before deformation. When the reduced diameter rate is less than or equal to the preset value, the casing is repaired by a shaping process at the reduced diameter position. The repaired inner diameter of the casing is obtained after the casing is repaired by the shaping process. It is determined whether the difference between the repaired inner diameter and the initial inner diameter is less than or equal to the first distance. When the difference between the repaired inner diameter and the initial inner diameter is less than or equal to the first distance, the casing is repaired by an expansion tube process. Since the expansion tube process utilizes an expansion tube compensation process, the casing can be supported by an expansion tube at the repair position of the casing in the shaping process, thereby preventing the casing from shrinking again at the repair position of the shaping process, thereby improving the stability of the casing to ensure that the repair effect of the casing meets the production requirements of the oil and water wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of a process for repairing a casing of an oil and water well provided for one or more embodiments of the present application;

[0041] Figure 2 Another flow chart of a process for repairing oil and water well casing provided for one or more embodiments of the present application. DETAILED DESCRIPTION

[0042] In order to make the technical personnel in the technical field to which the present application belongs to understand the present application more clearly, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0043] As oilfield development enters the middle and late stages, more and more oil and water well casings are damaged. Casing damage will not only directly affect the normal production of oil and water wells, but also affect neighboring wells, and even cause regional casing damage, resulting in greater losses. Casing repair is a special repair technology for oil and water wells with damaged casings, and is also an important means to restore normal production of oil and water wells.

[0044] In the related art, due to the limitation of casing repair technology, repairing a severely shrunken casing using conventional casing repair technology is prone to accidents such as casing window opening or casing rebound, resulting in poor casing repair effect that cannot meet the production needs of oil and water wells.

[0045] In order to solve the technical problem in the related art that the repair effect of the sleeve is poor and cannot meet the production needs of oil and water wells, the present application provides a process method for repairing the casing of an oil and water well.

[0046] See also Figure 1 , Figure 1 A flow chart of a process for repairing oil and water well casing is provided for one or more embodiments of the present application.

[0047] like Figure 1 As shown, the process for repairing the casing of an oil and water well at least includes:

[0048] S102: Obtain the reduced diameter position in the sleeve and the reduced diameter rate of the sleeve.

[0049] During the production process of oil and water wells, when the production tool is lowered along the casing to the designated operating position in the oil and water well, if the production tool encounters an obstacle and gets stuck in the casing, it can be determined that the casing has been reduced in diameter. The diameter of the pipe at the reduced diameter position becomes smaller, causing the production tool to be unable to pass through and get stuck in the casing.

[0050] When it is determined that there is a reduction in diameter inside the sleeve, a measuring tool can be used to measure the deformed inner diameter of the sleeve after deformation and the initial inner diameter before deformation at the reduced diameter position inside the sleeve (that is, the actual inner diameter of the sleeve, which can also be obtained by querying relevant documents). The reduction rate is calculated from the deformed inner diameter after deformation and the initial inner diameter before deformation. Specifically, the difference between the initial inner diameter and the deformed inner diameter is the deformation amount of the sleeve inner diameter, and the ratio of the deformation amount of the sleeve inner diameter to the initial inner diameter before deformation is the reduction rate. According to the obtained reduced diameter position of the sleeve, the sleeve repair tool can be directly lowered to the reduced diameter position to repair the sleeve, thereby improving the repair efficiency and accuracy of the sleeve.

[0051] S104: When the reduction ratio is less than or equal to a preset value, a shaping process is used to repair the sleeve at the reduction position.

[0052] In order to ensure the repair quality of the sleeve, it is necessary to select the corresponding repair process according to the shrinkage rate of the sleeve. Specifically, the shrinkage rate of the sleeve is compared with the preset value. When the shrinkage rate of the sleeve is less than or equal to the preset value, the shrinkage position in the sleeve can be repaired by a shaping process. The sleeve is usually made of steel material, and the preset value can be determined based on comprehensive factors such as the steel grade of the steel used to make the sleeve, the wall thickness of the sleeve, the fastening quality of the sleeve, and the surface pressure. Usually, the preset value can be 20%. When the shrinkage rate of the sleeve is less than or equal to 20%, a shaping process is used to repair the sleeve at the shrinkage position in the sleeve.

[0053] It should be noted that the pipe sleeve can also be made of other materials, which can be set according to actual needs and is not limited in this application.

[0054] S106, obtaining a repaired inner diameter of the pipe sleeve after the pipe sleeve is repaired by the shaping process.

[0055] The shaping process usually uses the expansion head to lightly stop the reduced diameter position multiple times under a set pressure, so that the expansion head passes through the reduced diameter position in the sleeve. In this way, the reduced diameter position of the sleeve is repaired to increase the repaired inner diameter, so that the production tool can pass through the reduced diameter position.

[0056] After using the expansion head with the required outer diameter to repair the reduced diameter position in the sleeve, use the measuring tool to obtain the repaired inner diameter of the sleeve, so that the repair condition of the sleeve after the shaping process can be determined more accurately.

[0057] S108: Determine whether the difference between the repaired inner diameter and the initial inner diameter is less than or equal to a first distance.

[0058] S110: When the difference between the repair inner diameter and the initial inner diameter is less than or equal to the first distance, the pipe sleeve is repaired by using an expansion pipe process.

[0059] The stability of the sleeve varies depending on the material it is made of. For a sleeve with resilience, after plastic repair, the sleeve will shrink again at the plastic repair position, causing the production tool to be unable to pass through and get stuck in the sleeve.

[0060] The measured repair inner diameter is subtracted from the initial inner diameter before the sleeve is deformed, and it is determined whether the difference is less than or equal to the first distance. When the difference between the repair inner diameter and the initial inner diameter before the sleeve is deformed is less than or equal to the first distance, the expansion tube process is used to repair the sleeve. The expansion tube process is to use the expansion tube patching process to support the sleeve at the repair position of the shaping process of the sleeve to prevent the sleeve from shrinking again at the repair position of the shaping process, and to improve the stability of the sleeve to ensure that the repair effect of the sleeve meets the production requirements of oil and water wells.

[0061] It should be noted that, since the expansion tube used in the expansion tube process needs to occupy the inner diameter of the tube sleeve, the first distance needs to be determined according to the passage space of the production tool and the size of the inner diameter of the tube sleeve occupied by the expansion tube, so as to ensure that the position of the plastic repair in the tube sleeve can be repaired by the expansion tube process, and the production tool can pass through the expansion tube. In this way, the stability of the tube sleeve can be ensured, and the normal passage of the production tool in the tube sleeve can be ensured.

[0062] The present application also provides a process for repairing oil and water well casing. Figure 2 , Figure 2 Another flow chart of a process for repairing oil and water well casing provided for one or more embodiments of the present application.

[0063] like Figure 2 As shown, the process for repairing the casing of an oil and water well at least includes:

[0064] S202: Perform a well-washing operation on the casing, wherein the well-washing operation includes cleaning the inner wall of the casing.

[0065] During the production process of oil and water wells, when the production tool is lowered along the casing to the designated working position in the oil and water wells, if the production tool encounters an obstacle and gets stuck in the casing, it can be determined that the casing has shrunk in diameter, and the diameter of the pipe at the shrunk position has become smaller, causing the production tool to be unable to pass through and get stuck in the casing.

[0066] When it is determined that the pipe sleeve has a reduced diameter, a well washing and pressure operation is performed on the pipe sleeve, and the well washing and pressure operation includes cleaning the inner wall of the pipe sleeve. Specifically, cleaning the inner wall of the pipe sleeve can ensure that the inner wall of the pipe sleeve is relatively clean, which is convenient for subsequent repair of the reduced diameter position in the pipe sleeve, and improves the quality and convenience of repairing the reduced diameter position in the pipe sleeve.

[0067] S204, measuring the reduced diameter position in the sleeve, the deformed inner diameter of the sleeve after deformation, and the initial inner diameter of the sleeve before deformation.

[0068] After the inner wall of the casing is cleaned, the measuring tool can be used to measure the shrinkage position in the casing, the deformed inner diameter after the casing is deformed, and the initial inner diameter before the casing is deformed. Specifically, the condition inside the casing can be diagnosed by using downhole television or multi-arm caliper and other detection means to determine the shrinkage position in the casing, the deformed inner diameter after the casing is deformed, and the initial inner diameter before the casing is deformed. Since the inner wall of the casing is relatively clean, the measurement accuracy of the shrinkage position in the casing, the deformed inner diameter after the casing is deformed, and the initial inner diameter before the casing is deformed can be improved.

[0069] In order to maintain the pressure balance in the casing, after obtaining the reduced diameter position, deformed inner diameter and initial inner diameter in the casing, a well-killing fluid can be injected into the casing to maintain the pressure balance in the casing, prevent the casing from overflowing during the repair process, and improve the safety of casing repair. It should be noted that the well-killing fluid can be clean water or other liquids, which is not limited in this application and can be set according to actual needs.

[0070] S206: Obtain the reduced diameter position in the sleeve and the reduced diameter rate of the sleeve.

[0071] Please refer to step S102, which will not be described in detail here.

[0072] S208. When the reduction ratio is less than or equal to a preset value, a shaping process is used to repair the sleeve at the reduction position.

[0073] In order to ensure the repair quality of the sleeve, it is necessary to select the corresponding repair process according to the shrinkage rate of the sleeve. Specifically, the shrinkage rate of the sleeve is compared with the preset value. When the shrinkage rate of the sleeve is less than or equal to the preset value, the shrinkage position in the sleeve can be repaired by a shaping process. The sleeve is usually made of steel material, and the preset value can be determined based on comprehensive factors such as the steel grade of the steel used to make the sleeve, the wall thickness of the sleeve, the fastening quality of the sleeve, and the surface pressure. Usually, the preset value can be 20%. When the shrinkage rate of the sleeve is less than or equal to 20%, a shaping process is used to repair the sleeve at the shrinkage position in the sleeve.

[0074] It should be noted that the pipe sleeve can also be made of other materials, which can be set according to actual needs and is not limited in this application.

[0075] The shaping process may use hydraulic shaping, and the shaping construction pipe string used in the shaping process includes a shaping pipe string, a first expansion head and a weight indicator, the first expansion head and the weight indicator are respectively connected to the shaping pipe string, and the first expansion head is located below the shaping pipe string. The shaping process includes: lowering the first expansion head along the extension direction of the sleeve to the reduced diameter position, continuously lowering the first expansion head until the weight indicator shows zero, and pressing the shaping construction pipe string until the first expansion head can pass through the reduced diameter position.

[0076] Specifically, when the sleeve is shaped for the first time using the shaping process, a first expansion head with a maximum outer diameter 4 mm larger than the inner diameter of the sleeve after deformation and a 700-type pump truck can be used to provide hydraulic pressure. When the high-pressure pipeline connected to the shaping pipe column is energized, the shaping pipe column can be lowered along the extension direction of the sleeve, so that the first expansion head is lowered to the reduced diameter position, and the shaping pipe column is continued to be lowered. When the first expansion head abuts against the reduced diameter position in the sleeve, the weight indicator will show resistance. The first expansion head is continuously lowered several times using the deadweight of the shaping construction pipe column until the weight indicator shows zero (the position where the weight indicator shows zero can be recorded as the resistance position). At this time, all the weight of the shaping construction pipe column is pressed at the resistance position. At this time, hydraulic pressure can be used to pressurize the shaping construction pipe column to increase the pressure of the first expansion head hitting the reduced diameter position, so that the first expansion head can pass through the reduced diameter position.

[0077] It should be noted that a plurality of rolling balls are arranged on the circumference of the first expanding head, and the rolling balls are convexly arranged on the circumference of the first expanding head and are rotatably connected with the first expanding head. Lowering the first expanding head along the sleeve to the reduced diameter position specifically includes: placing the first expanding head into the sleeve, making the rolling balls slidably connected with the inner wall of the sleeve, and lowering the first expanding head to the reduced diameter position along the extension direction of the sleeve.

[0078] Specifically, a high-strength steel ball is arranged on the outside of the first expansion head, and the highest point of the outer surface of the steel ball is usually 4mm higher than the outer side surface of the first expansion head, so that the steel ball can protrude from the first expansion head and slide in connection with the inner wall of the sleeve. At the same time, at least 4 circles can be arranged at equal distances along the axial direction of the first expansion head, and the distance between two adjacent circles of steel balls can be 80mm. Since the steel ball can be slidably connected with the inner wall of the sleeve by rotation, when the first expansion head moves relative to the inner wall of the sleeve through the steel ball, the smoothness of the movement of the first expansion head in the sleeve can be improved, and the situation of the shaping column being stuck in the sleeve can be prevented, ensuring that the shaping process can be carried out in the sleeve to repair the sleeve.

[0079] The shaping construction pipe string is pressurized until the first expansion head can pass through the reduced diameter position, specifically comprising: applying a first pressure to the shaping construction pipe string, lowering the first expansion head until the indicator weight meter displays zero; and applying a second pressure to the shaping construction pipe string multiple times until the first expansion head passes through the reduced diameter position.

[0080] Specifically, the first pressure of the shaping construction pipe string for the first time can be 10MPa. After stabilizing the pressure for 5 minutes, the shaping pipe string is lifted up, and then the shaping pipe string is lowered until the indicator weight meter shows zero. The second pressure is increased to the shaping construction pipe string multiple times, and the second pressure increased each time can be 5MPa. The total pressure is not higher than 25MPa. The shaping pipe string is lowered until the first expansion head can pass through the reduced diameter position in the pipe sleeve.

[0081] In order to know the shaping effect of the shaping process, when the shaping pipe column is lowered for the first time along the extension direction of the pipe sleeve until the indicator weight meter shows zero, a mark can be made at the appropriate position where the shaping pipe column protrudes from the ground. The shaping construction pipe column is pressed and the shaping pipe column is lowered until the indicator weight meter shows zero. If the mark position made at the position where the shaping pipe column protrudes from the ground moves downward, it means that the shaping process is effective; if the mark position remains unchanged, it means that the shaping process is ineffective.

[0082] It should be noted that the shaping effect of the shaping process after each pressing can be known by making marks before and after each pressing and observing the downward movement of the marked position.

[0083] After the first expansion head can pass through the reduced diameter position in the sleeve, the shaping pipe string is taken out from the sleeve, and the first expansion head is replaced with a second expansion head, and the difference between the outer diameter of the second expansion head and the outer diameter of the first expansion head is greater than or equal to the preset outer diameter difference; the second expansion head is lowered along the extension direction of the sleeve to the reduced diameter position; the second expansion head is continuously lowered until the indicator weight meter displays zero; the shaping construction pipe string is pressed until the second expansion head passes through the reduced diameter position.

[0084] According to the shaping situation of the on-site sleeve, the outer diameter of the second expansion head can be selected to have a difference greater than or equal to the preset outer diameter difference with the outer diameter of the first expansion head, and the preset outer diameter difference is usually 2mm to 4mm. The second expansion head is used for the shaping process, and the second expansion head is lowered to the reduced diameter position along the extension direction of the sleeve; the second expansion head is continuously lowered until the indicator weight meter shows zero (the position where the indicator weight meter shows zero can be recorded as the resistance position), and all the weight of the shaping construction pipe column is pressed at the resistance position. At this time, hydraulic pressure can be used to pressurize the shaping construction pipe column to increase the pressure of the second expansion head at the reduced diameter position, so that the second expansion head can pass through the reduced diameter position. The shaping capacity of each expansion head is controlled within the range of 2mm to 4mm compared with the previous expansion head. The smaller change in the outer diameter of the expansion head can prevent the shaping pipe column from being stuck in the sleeve. According to the shaping requirements of the sleeve, the sleeve can also be shaped by replacing the third, fourth and fifth expansion heads until the outer diameter of the expansion head is 6mm to 8mm smaller than the inner diameter of the sleeve. The hydraulic shaping of the sleeve is completed and the shaping pipe column can be taken out of the sleeve. The outer diameters of different expansion heads gradually increase, which can expand the shaping range of the shaping process to meet the needs of various sizes of shrinkage in the sleeve and improve the applicability of the shaping process.

[0085] The shaping process adopts hydraulic shaping process. When the shaping construction pipe column is placed in the pipe sleeve along the extension direction of the pipe sleeve, the shaping construction pipe column can include the first expansion head, hydraulic cylinder, hydraulic anchor, lifting oil drain, filter short section, lifting short section, ball-throwing pressure type safety joint and weight indicator from bottom to top. The shaping pipe column is connected to the upper part of the ball-throwing pressure type safety joint, and the weight indicator is connected to the outer side of the first expansion head. The maximum outer diameter of the ball-throwing pressure type safety joint can be set to be 4mm smaller than the maximum outer diameter of the first expansion head, and steps should be avoided at the connection position of the two adjacent parts in the shaping construction pipe column, so as to prevent the shaping construction pipe column from being stuck during the lowering process along the pipe sleeve, so that the shaping construction pipe column can be smoothly lowered along the axis of the pipe sleeve to the reduced diameter position in the pipe sleeve for pipe sleeve repair.

[0086] It should be noted that when it is determined that the reduction rate of the sleeve is less than or equal to 20%, the sleeve can be repaired at the reduced diameter position inside the sleeve by using a mechanical shaping process. The shaping pipe string can be repaired by using its own weight and moving it up and down several times. If the shaping pipe string still cannot pass through the reduced diameter position inside the sleeve after three back and forth movements, a hydraulic shaping process can be used.

[0087] S210, obtaining a repaired inner diameter of the sleeve after the sleeve is repaired by the shaping process.

[0088] Please refer to step S106, which will not be described in detail here.

[0089] S212: Determine whether the difference between the repaired inner diameter and the initial inner diameter is less than or equal to a first distance.

[0090] Please refer to step S108, which will not be described in detail here.

[0091] S214. When the difference between the repair inner diameter and the initial inner diameter is less than or equal to the first distance, the pipe sleeve is repaired by using an expansion pipe process.

[0092] The stability of the sleeve varies depending on the material it is made of. For a sleeve with resilience, after plastic repair, the sleeve will shrink again at the plastic repair position, causing the production tool to be unable to pass through and get stuck in the sleeve.

[0093] In order to prevent the sleeve from shrinking again at the repair position of the shaping process, when the difference between the repair inner diameter and the initial inner diameter is less than or equal to the first distance, the expansion tube process is used to repair the sleeve. The expansion tube process is a process that uses an expansion tube to support the sleeve at the repair position of the shaping process of the sleeve to prevent the sleeve from shrinking again and improve the stability of the sleeve.

[0094] It should be noted that, since the expansion tube used in the expansion tube process needs to occupy the inner diameter of the tube sleeve, the first distance needs to be determined according to the passage space of the production tool and the size of the inner diameter of the tube sleeve occupied by the expansion tube, so as to ensure that the position of the plastic repair in the tube sleeve can be repaired by the expansion tube process, and the production tool can pass through the expansion tube. In this way, the stability of the tube sleeve can be ensured, and the normal passage of the production tool in the tube sleeve can be ensured.

[0095] The expansion pipe process uses an expansion construction pipe string including an expansion pipe string and a weight indicator. The expansion pipe process includes: lowering the expansion pipe string to the reduced diameter position, pressing the expansion pipe string, and expanding the expansion pipe string until the expansion pipe fits the inner wall of the pipe sleeve.

[0096] Specifically, the hydraulic pressure of the expansion construction pipe string can be provided by a 700-type pump truck, and the pressure resistance of the high-pressure pipeline used is greater than or equal to 50MPa. Since the expansion pipe process needs to occupy the inner diameter of the pipe sleeve, the order of subsidizing the expansion pipe to the inner wall of the pipe sleeve using the expansion pipe process needs to be subsidized from bottom to top along the extension direction of the pipe sleeve.

[0097] The expansion construction string may also include a salvageable bottom plug, a pressure-up joint and an oil pipe. When the expansion construction string is placed in the casing to repair the casing by the expansion pipe process, the expansion construction string may include a salvageable bottom plug, an expansion string, a pressure-up joint and an oil pipe in sequence from bottom to top along the extension direction of the casing, the weight indicator is connected to the expansion string, and the end of the oil pipe may extend into the expansion string.

[0098] The expansion pipe process includes: the expansion pipe string is lowered with the expansion pipe to the reduced diameter position (to be compensated position) in the pipe casing, the ground pressure pipeline is connected and the 700-type pump truck is started, and the expansion pipe string begins to be pressurized to expand the expansion pipe. At this time, the hook position of the crane connected to the expansion pipe string and used to pull the expansion pipe string is stable to ensure that the position of the expansion pipe string in the pipe casing is determined. When the pressure of the expansion pipe string is 25MPa, the expansion pipe string drives the expansion pipe to expand so that the expansion pipe fits the inner wall of the pipe casing, the friction between the expansion pipe and the pipe casing increases, and the reading of the weight indicator becomes smaller.

[0099] When the expansion pipe string has been extended 0.5m in the extension direction of the casing, the expansion pipe string is lifted until it returns to its original hanging weight and remains unchanged. This indicates that the lower end of the expansion pipe has been firmly attached to the inner wall of the casing, which can also provide anchoring force for continuing to pressurize the expansion pipe string.

[0100] It is determined whether the expansion string can be lifted and started. If not, the auxiliary lifting load of the expansion string is increased or the thickness of the expansion tube is reduced.

[0101] Specifically, when the expansion string is used to supplement the expansion tube to the corresponding position in the casing, the hook of the crane needs to lift the expansion string along the extension direction of the casing, so that the expansion string moves to the position in the casing where the expansion tube needs to be supplemented. Usually, the starting pressure of the expansion construction string is less than or equal to 25MPa, and the auxiliary load of the hook of the crane is less than or equal to 20t. That is to say, the starting pressure of the expansion construction string is usually 25MPa, and the expansion string can be lifted along the extension direction of the casing. Since the expansion string is subject to the resistance of the expansion tube during the lifting process, if the starting pressure of the expansion construction string is greater than 25MPa, the lifting force of the hook of the crane can be increased according to actual needs, so that the expansion string is lifted in the expansion tube along the extension direction of the casing. It is also possible to reduce the wall thickness of the expansion tube, reduce the resistance of the expansion string in the expansion tube, reduce the lifting force of the expansion string, ensure that the expansion string can be lifted in the expansion tube along the extension direction of the casing, and reduce the difficulty of starting the expansion construction string. Until the expansion string is lifted to the position where the expansion tube needs to be supplemented, pressurize the expansion string so that the expansion tube is supplemented to the reduced diameter position in the casing. Continue to lift the expansion string so that the expansion string is lifted along the extension direction of the casing, and ensure that the reading of the weight gauge is near the original hanging weight of the expansion string to ensure that the expansion tube can be supplemented to the reduced diameter position in the casing. When the pressure on the weight gauge drops to zero, it indicates that the expansion string is detached from the expansion tube, and the expansion tube is fully supplemented to the reduced diameter position in the casing. At this time, the expansion construction string can be taken out of the casing, and the expansion tube process is completed. The expansion tube process utilizes the expansion tube supplementation process, and uses the expansion tube to support the casing at the position where the casing is repaired during the shaping process to prevent the casing from shrinking again and improve the stability of the casing.

[0102] After the pipe sleeve is repaired by the expansion pipe process, it is necessary to test the sealing of the pipe sleeve. The test pressure is 15MPa, and it is left to stand for 30 minutes. The pressure drop in the pipe sleeve is tested by the pressure gauge. When the pressure drop in the pipe sleeve is less than 0.5MPa, it means that the sealing of the pipe sleeve is good and the repair of the reduced diameter position in the pipe sleeve is relatively complete.

[0103] S216. When the difference between the repaired inner diameter and the initial inner diameter is greater than the first distance, determine whether the difference between the repaired inner diameter and the initial inner diameter and the first distance is less than or equal to a second distance.

[0104] For a sleeve with resilience, after the sleeve is repaired by the shaping process, the repaired inner diameter of the sleeve is measured using a well gauge according to the standard of 6mm to 8mm smaller than the inner diameter of the sleeve. If the well gauge can pass through the reduced diameter position of the sleeve after the shaping process, it means that the sleeve is successfully repaired using the shaping process. If the well gauge cannot pass through the reduced diameter position of the sleeve after the shaping process, it means that the reduced diameter position repaired by the shaping process in the sleeve rebounds. In other words, the sleeve is reduced again at the repair position of the shaping process, and the difference between the repaired inner diameter and the initial inner diameter is greater than the first distance, and the production tool cannot pass through and is stuck in the sleeve.

[0105] S218. When the difference between the repaired inner diameter and the initial inner diameter of the sleeve before deformation and the difference between the first distance and the first distance are greater than the second distance, the shaping process is used to repair the sleeve.

[0106] According to the actual situation, the second distance can be set to 4mm. If the difference between the repaired inner diameter and the initial inner diameter is less than or equal to 4mm, it means that the sleeve rebounds seriously and the sleeve needs to be repaired by the shaping process again (or the shaping process is used to repair the sleeve multiple times) until the difference between the repaired inner diameter and the initial inner diameter before the sleeve is deformed is less than or equal to 4mm.

[0107] S220: When the difference between the repaired inner diameter and the initial inner diameter of the sleeve before deformation and the difference between the first distance and the first distance are less than or equal to the second distance, the sleeve is repaired by a milling process.

[0108] When the difference between the repaired inner diameter and the initial inner diameter of the sleeve before deformation and the difference between the first distance and the first distance are less than or equal to 4 mm, it indicates that the resilience of the sleeve is small and the sleeve can be repaired by milling process.

[0109] The milling construction pipe string used in the milling process at least includes a milling pipe string and a milling cone, and the milling pipe string is connected to the milling cone through a safety joint. When the milling construction pipe string is placed in the casing for casing repair, the milling cone, the safety joint and the milling pipe string are arranged in sequence from bottom to top, and the maximum outer diameter of the safety joint is less than or equal to the maximum outer diameter of the milling cone. At the same time, the power faucet or hydraulic turntable can be used to provide the rotation power of the milling pipe string, and the 400-type pump truck or the 700-type pump truck provides the circulation power of the well repair fluid and adopts a positive circulation to provide the circulation power. The outer diameter of the milling cone can usually be set to be 6mm smaller than the inner diameter of the casing, so that the inner diameter of the reduced diameter position repaired by the milling process is close to the initial inner diameter, so that a larger repair space can be reserved to facilitate the repair of the casing; at the same time, it can avoid leakage of the casing and prevent the occurrence of casing window. When the milling construction pipe string can pass through the reduced diameter position without pressure and the milling cone does not rotate, it means that the reduced diameter position of the sleeve is completed. Then the expansion tube process can be used to repair the sleeve and reinforce the reduced sleeve to improve the stability of the sleeve.

[0110] In the milling process, multiple milling cones with different outer diameters can also be used to mill the reduced diameter positions. The outer diameters of different milling cones gradually increase, which can expand the milling range of the milling process to meet the needs of reducing diameters of various sizes in the pipe sleeve, thereby improving the applicability of the milling process.

[0111] It should be noted that for a pipe sleeve with resilience, the shaping process, grinding and milling process and expansion tube process can be used in sequence to repair the pipe sleeve. The repair process of the pipe sleeve can be adjusted according to the needs of the on-site situation. The repair process is safe, controllable and highly adaptable. The shaping process, grinding and milling process and expansion tube process are simple to operate, which can reduce the repair cost and improve the repair efficiency. At the same time, the operating equipment used for repairing the pipe sleeve by the shaping process, grinding and milling process and expansion tube process is simple in structure, small in overall structure, short in construction time, high in operating efficiency, and can improve the efficiency of pipe sleeve repair.

[0112] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0113] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0114] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0115] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0116] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A process for repairing oil and water well casing, characterized in that: include: Obtaining a reduced diameter position in the sleeve and a reduced diameter rate of the sleeve, wherein the reduced diameter rate is calculated based on a deformed inner diameter of the sleeve after deformation and an initial inner diameter of the sleeve before deformation; When the reduction ratio is less than or equal to a preset value, a shaping process is used to repair the sleeve at the reduction position; After the sleeve is repaired by the shaping process, a repaired inner diameter of the sleeve is obtained; Determining whether the difference between the repaired inner diameter and the initial inner diameter is less than or equal to a first distance; When the difference between the repair inner diameter and the initial inner diameter is less than or equal to the first distance, the pipe sleeve is repaired by using an expansion pipe process.

2. The process for repairing oil and water well casing according to claim 1, characterized in that: Also includes: When the difference between the repaired inner diameter and the initial inner diameter is greater than the first distance, determining whether the difference between the repaired inner diameter and the initial inner diameter and the first distance is less than or equal to a second distance; When the difference between the repaired inner diameter and the initial inner diameter and the difference between the first distance and the second distance is greater than the second distance, the sleeve is repaired by the shaping process; When the difference between the repaired inner diameter and the initial inner diameter and the difference between the first distance is less than or equal to the second distance, the sleeve is repaired by a milling process.

3. The process for repairing oil and water well casing according to claim 1, characterized in that: Before obtaining the reduced diameter position in the sleeve and the reduced diameter rate of the sleeve, the method further includes: A well washing and pressure reducing operation is performed on the pipe casing, wherein the well washing and pressure reducing operation includes cleaning the inner wall of the pipe casing.

4. The process for repairing oil and water well casing according to claim 3 is characterized in that: After the well washing and pressure operation is performed on the casing, and before the shrinkage position in the casing and the shrinkage rate of the casing are obtained, the method further includes: The reduced diameter position in the sleeve, the deformed inner diameter of the sleeve after deformation, and the initial inner diameter of the sleeve before deformation are measured.

5. The process for repairing oil and water well casing according to claim 1, characterized in that: The shaping construction pipe string used in the shaping process includes a shaping pipe string, a first expansion head and a weight indicator, wherein the first expansion head and the weight indicator are respectively connected to the shaping pipe string; the shaping process includes: Lowering the first expansion head along the extension direction of the sleeve to the reduced diameter position; Continue to lower the first expansion head until the weight indicator shows zero; The shaping construction pipe string is pressed until the first expansion head can pass through the reduced diameter position.

6. The process for repairing oil and water well casing according to claim 5, characterized in that: A plurality of rolling balls are arranged on the peripheral side of the first expanding head, and the rolling balls are convexly arranged on the peripheral side of the first expanding head and are rotatably connected to the first expanding head; The step of lowering the first expansion head to the reduced diameter position along the extension direction of the sleeve comprises: Put the first expansion head into the sleeve so that the rolling ball is slidably connected with the inner wall of the sleeve; The first expansion head is lowered to the reduced diameter position along the extension direction of the sleeve.

7. The process for repairing oil and water well casing according to claim 5, characterized in that: The step of pressing the shaping construction pipe string until the first expansion head can pass through the reduced diameter position includes: Applying a first pressure to the shaping construction pipe string, lowering the first expansion head until the indicator weight meter shows zero; The second pressure is applied to the shaping construction pipe string for multiple times until the first expansion head passes through the reduced diameter position.

8. The process for repairing oil and water well casing according to claim 5, characterized in that: After lowering the first expansion head to the reduced diameter position along the extension direction of the sleeve, the method further comprises: The first bulging head is replaced with a second bulging head, wherein the difference between the outer diameter of the second bulging head and the outer diameter of the first bulging head is greater than or equal to a preset outer diameter difference; Lowering the second expansion head along the extension direction of the sleeve to the reduced diameter position; Continue to lower the second expansion head until the weight indicator shows zero; The shaping construction pipe string is pressed until the second expansion head passes through the reduced diameter position.

9. The process for repairing oil and water well casing according to claim 1, characterized in that: The expansion pipe process uses an expansion construction pipe string including an expansion pipe string and a weight indicator connected to the expansion pipe string, and the expansion pipe process includes: Lowering the expansion pipe string to the reduced diameter position; The expansion pipe string is pressurized to expand the expansion pipe string until the expansion pipe fits the inner wall of the pipe sleeve.

10. The process for repairing oil and water well casing according to claim 8, characterized in that: The step of pressing the shaping construction pipe string until the second expansion head passes through the reduced diameter position further comprises: Determine whether the expansion string can be lifted and started; If not, increase the auxiliary lifting load of the expansion pipe string or reduce the thickness of the expansion pipe.

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