Restricted well site workover operation technology

Abstract

The invention discloses a limited well site workover operation technology, and belongs to the technical field of oil field downhole operation. According to the technical scheme, a limited well site workover operation device is installed; executing a hydraulic lifting and lowering tubular column operation process; executing a cycle operation process; salvage and jam releasing processes are executed; and executing a rotation operation process. The device has the beneficial effects that through the limited well site workover operation process research and the tubular column lifting operation process, the equipment lifting force is 600 kN, and the downward pressure is 350 kN; the operation process is circulated, and well washing, sand washing and casing grinding and milling construction can be carried out; the conventional fishing, reversing and unfreezing construction can be completed through the fishing and unfreezing operation process; by means of the rotating operation technology, operations such as back-off, sleeve grinding and milling and pipe column rotating can be achieved, and the maximum torque is 8400 N.M; the limited well site equipment installation technology meets the requirement for sensitive area workover operation within the range that the distance between a well mouth of an operation well and an obstacle is 3 m and the well site area is 50 m < 2 >, and the occupied area of equipment is predicted to be reduced by 87.5%.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oilfield downhole operation, and particularly relates to a workover operation process for a restricted well site. BACKGROUND

[0002] At present, there are several wells with hidden dangers to be treated in each major oilfield, and some of the wells are located in restricted space areas such as residential areas and industrial plant areas, and the environment is sensitive, which has great safety and environmental protection hidden dangers. However, due to the influence of factors such as narrow well site and difficult land acquisition, the well site conditions do not meet the installation requirements of the conventional workover operation equipment, and the wells with hidden dangers have not been treated. Taking the well site condition requirements of XJ90Z workover unit operation construction as an example, the equipment is 11.0m long and 2.9m wide, the minimum installation area of the ground anchor is an isosceles trapezoid with an upper base of 17m, a lower base of 27m and a height of 22m, the pipe bridge is a square of 10m x 10m, and the occupied area is about 400㎡. The equipment parameters of the workover unit without a bridle rope are consistent with those of XJ90Z, and the occupied area is about 260㎡. The existing workover operation process uses single derrick snubbing unit (the height of the derrick is 18m) and self-back derrick workover unit (the height of the derrick is 21m), and adopts the conventional workover operation process, which has high requirements for the occupied area and height of the well site, and some well sites do not have construction conditions.

[0003] If the construction conditions are met, great damage will be caused to the surrounding environment; manual unhooking and hooking of the elevator is required during the conventional operation construction, and the labor intensity is high; the self-sealing rubber core is used to close the oil sleeve annulus during the sand washing process of the conventional minor repair operation, and the rubber core is easily damaged due to the influence of friction and high pressure, which affects the construction progress; when the well has an abnormally high pressure and the pipe string hanging weight is less than the upward force generated in the wellbore, the pipe string may fly out, causing personnel injury and equipment damage.

[0004] In order to effectively solve the problem and treat the wells with hidden dangers in the restricted well site, the workover operation process for the restricted well site is developed. SUMMARY

[0005] In order to solve the problems in the prior art, the present application provides a workover operation process for a restricted well site, which mainly solves the key technical problems of the workover operation in the restricted well site by changing the original installation mode, lifting mode and operation mode, and meets the technical problems of the workover operation in the sensitive area within 3m from the wellhead to the obstacle and 50㎡ of the well site area.

[0006] To achieve the above object, the present application provides the following technical scheme:

[0007] A workover operation process for a restricted well site, and the process steps are as follows:

[0008] S1, installing a workover operation device for a restricted well site;

[0009] S2, performing hydraulic lifting and lowering string operation process;

[0010] S3, performing a cyclic operation process;

[0011] S4, performing fishing and unblocking process;

[0012] S5, performing a rotating operation process.

[0013] Further, in step S1, the limited well site workover operation device installation process is as follows:

[0014] S11, washing or killing the well until the wellhead is in a no overflow state;

[0015] S12, check and clean the blowout preventer steel ring groove, check whether the gate is flexible;

[0016] S13, remove the original wellhead flange bolts, and remove the original wellhead flange and the upper part with standard rigging;

[0017] S14, check and clean the large four-way steel ring groove, and confirm that it is intact. After confirming that it is intact, apply butter to the intact steel ring and put it into the steel ring groove;

[0018] S15, hoist the main device of the limited well site workover operation device, check and confirm that the rigging is special, and the equipment lifting point is intact; Install the rigging on the special lifting lug of the main device of the limited well site workover operation device, tie the traction rope at the lower end of the support frame, and command the crane to slowly lift the device as a whole and align the wellhead four-way, and then slowly lower it;

[0019] S16, after the bolts are inserted into the four-way, the main device is supported, and personnel enter the lower part of the main device to tighten the bolts;

[0020] S17, diagonally tighten the connecting bolts of the main device and the wellhead four-way, and fully tighten the connecting bolts of the main device and the wellhead four-way, and evenly distribute the remaining nuts at both ends;

[0021] S18, after the main device is installed, the widened platform, mast and slide are hoisted to the designated position of the platform with lifting belts, and the operating personnel fix them with pins; Install auxiliary equipment and facilities, connect hydraulic control pipelines; Determine that the hydraulic pipeline, blowout preventer group and manifold are qualified after pressure test.

[0022] Further, before the operation of the limited well site operation device, the main device is checked again according to the wellhead condition of the construction well, and the support is further reinforced to prevent damage to the wellhead device due to shaking and vibration during operation.

[0023] Further, after the installation of the underbalanced operation main device is completed, adjust the auxiliary legs to make the mast, traveling slips group and fixed slips group coaxial with the wellhead.

[0024] Further, in step S2, the string lifting step is as follows:

[0025] S21, close the mobile load slips, confirm that the load slips are in a fully closed state, load transfer: slowly raise the oil cylinder, concentrate the weight of the pipe string on the mobile load slips;

[0026] S22, open the fixed load slips;

[0027] S23, raise the pipe string, and make the tubing go up with the mobile load slips;

[0028] S24, close the fixed load slips, and measure the position of the lower tubing joint to avoid the fixed load slips clamping the joint;

[0029] S25, load transfer: lower the pipe string, and visually check the load indicator until the reading is completely released, at which time the weight of the pipe string is released to the fixed load slips;

[0030] S26, open the mobile load slips;

[0031] S27, lower the oil cylinder so that the mobile load slips are near the lower limit of the oil cylinder;

[0032] S28, close the mobile load slips;

[0033] S29, there is a reducer tool in the fixed load slips;

[0034] S210, use the hydraulic tong to release the tubing threads, and according to the principle of slow first and then fast, after the threads are completely loosened, the tubing can be lifted;

[0035] S211, the tubing after the clamp is sent to the pipe bridge along the slide.

[0036] Further, when the downhole tool and the last few tubings are lifted, the lifting speed is slowed down to prevent scratching, colliding with the wellhead, and causing the tool and pipe string to fall into the well; during the pipe string lifting process, the operator should pay attention to the change of the load value; when the load slips are closed, the closing state of the load slips should be observed to ensure that the pipe string is clamped, and when the load slips are opened, the load transfer should be prepared in advance to prevent the pipe string from falling into the well.

[0037] Further, in step S29, the reducer tool includes one or more of a tubing hanger, a variable buckle, a tubing joint, a tubing short joint, a packer, and a water distributor.

[0038] Further, in step S2, the pipe string lowering step is as follows:

[0039] S21, use the winch to lift the tubing ready to be lowered into the well from the ground to the working platform;

[0040] S22, lower the winch wire rope so that the tubing enters the annular blowout preventer and the fixed load slips in turn;

[0041] S23. Close the oil holding oil of the fixed load-bearing slip;

[0042] S24. Loosen the winch wire rope;

[0043] S25, the hydraulic cylinder of the upward working machine, so that the moving load-bearing slip is at a certain height;

[0044] S26. Close the movable load-bearing clamp;

[0045] S27, Load transfer: Lift the tubing column so that the weight of the tubing column is concentrated on the moving load-bearing slip;

[0046] S28. Open the retaining clip;

[0047] S29. The downward working machine approaches the downward stop point of the hydraulic cylinder;

[0048] S210, Close the fixed latch;

[0049] S211, Load transfer: Downward pressure tubing;

[0050] S212, Open the movable load-bearing clamp;

[0051] S213. Repeat steps S21-S212 to lower the tubing into the well one after another.

[0052] Furthermore, in step S3, the specific steps of the cyclic operation process are as follows:

[0053] S31. Lower the tubing string to the predetermined position, connect the inlet and outlet pipelines and the tap, close the annular blowout preventer, start the pump to circulate, and after the return liquid is normal, lower the tubing string at a uniform speed by alternating between moving load-bearing slips and fixed slips.

[0054] S32. Each time the tubing string is flushed down, full circulation is performed; after flushing down several individual tubing strings in succession, the well must be thoroughly flushed and circulated for one week before flushing can continue.

[0055] S33, wellhead staff, and pump truck personnel worked closely together to observe pump pressure and outlet return fluid.

[0056] Furthermore, if the pump truck malfunctions and needs to be stopped, the tubing string should be raised to a position away from the original sand surface; the sand flushing in the composite casing should be raised above the hanger; the sand flushing in the horizontal well should be raised above the horizontal section; and the tubing string should be moved repeatedly. If the floating hoisting system malfunctions, the well should be thoroughly circulated and flushed.

[0057] Furthermore, in step S4, the salvage and unblocking process steps are as follows:

[0058] S41. Select appropriate retrieval tools based on the fish situation in the well, and measure the tool's length, inner diameter, and outer diameter, and take photos of the tools; check the integrity of each component of the downhole tool, and lower the drill string to the predetermined position;

[0059] S42. If the equipment gets stuck after retrieval, the movable tubing string should be released, but the allowable load of the equipment and the retrieval tubing string must not be exceeded, and the retrieval tubing string must use thickened tubing.

[0060] S43. When releasing the tube, both the movable anti-top clamp and the movable load-bearing clamp should be closed simultaneously to prevent the tube column from accidentally moving upward and causing mechanical damage.

[0061] S44. If the lifting force does not meet the construction requirements when releasing the card, adjust the lifting cylinder overflow valve and the pressure adjustment of the lifting cylinder system to set the pressure.

[0062] S45. If the active card release is not activated, choose to withdraw the retrieval tool or pull out the retrieval string upside down, depending on the actual situation.

[0063] Furthermore, in step S5, the rotation process steps are as follows:

[0064] S51. Inspect the integrity of the turntable to ensure it is flexible and easy to use;

[0065] S52. Lower the drill string to the predetermined position and connect the inlet and outlet pipelines, as well as the faucet and hose.

[0066] S53. Lower the tool to the predetermined position, close the annular blowout preventer, and start the pump to circulate until the inlet and outlet liquid properties are consistent.

[0067] S54. Simultaneously close the movable load-bearing slip and the movable anti-top slip to prevent the pipe column from moving upwards.

[0068] Furthermore, step S5 also includes the following steps:

[0069] S55. Remove the hydraulic lines of the movable anti-top clamps and movable load-bearing clamps, and connect the hydraulic lines of the turntable;

[0070] S56. Start the rotary table, slowly lower the tubing, pressurize, and return the annulus upwards;

[0071] S57. When the movable slip reaches the lowest point, stop the turntable from rotating. Connect the movable anti-overhead slip and movable load-bearing slip pipelines, close the fixed slip, open the movable load-bearing slip and movable anti-overhead slip, raise the oil cylinder to the upper end, and repeat steps S54-S57 to slowly drill the oil pipe to the predetermined position.

[0072] The beneficial effects of this invention are as follows: Through research on well workover operation technology in restricted well sites, this invention provides a tubing string running-in / running operation process with a lifting force of 600kN and a downcomer pressure of 350kN; a circulation operation process that can perform well washing, sand flushing, and milling operations; a fishing and unsticking operation process that can complete conventional fishing, reverse threading, and unsticking operations; a rotation operation process that can realize reverse threading, milling, and tubing string rotation operations, with a maximum torque of 8400N.M; and a restricted well site equipment installation process that meets the requirements for well workover operations in sensitive areas within a 3-meter distance from the wellhead to obstacles and a well site area of ​​50㎡, with an estimated reduction in equipment footprint of 87.5%. Attached Figure Description

[0073] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0074] Figure 1 This is an assembly drawing of the confined well site workover device of the present invention. Detailed Implementation

[0075] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The following description, in conjunction with the accompanying drawings... Figure 1 Further explanation of the well workover process in restricted well sites.

[0076] This technology changes the existing operation mode, forming a new technical system for well workover operations in confined well sites. It meets the requirements of various construction procedures, including tubing tripping, circulation, rotary drilling, fishing, and unsticking. It addresses existing technical problems through the following solutions: First, it changes the drive method from diesel engine to hydraulic drive, effectively solving noise pollution; second, it adds a mast system, changing the single-joint connection process to using a hydraulic winch on the mast for lifting and lowering single joints; third, it utilizes hydraulic lifters for lifting and lowering, changing the tubing tripping process; and fourth, it equips the operating platform with a hydraulic rotary table, changing the rotary operation process to meet drilling and grinding requirements. This technology breaks with traditional well workover operation thinking and mainly consists of the following five processes:

[0077] I. Installation and Operation Procedures for Equipment in Restricted Well Sites:

[0078] Restricted well site equipment such as Figure 1As shown, it had previously applied for a patent. The equipment consists of a double-gate blowout preventer, a lifting four-way short section, a lifting cylinder, a balance valve and a relief valve, a fixed slip blowout preventer, a ring blowout preventer, a movable top slip, a hydraulic turntable, a movable load-bearing slip, a mast, and a hydraulic winch.

[0079] This application only presents a preferred embodiment; other restricted well site equipment with the same function can also be applied to the relevant processes of this application.

[0080] (1) Wash or kill the well until there is no overflow at the wellhead.

[0081] (2) Check and clean the blowout preventer steel ring groove, and ensure that the gate switch is flexible.

[0082] (3) Remove the bolts on the original wellhead large four-way flange (remove the bolts in order of difficulty first), use standard rigging to remove the original wellhead flange and above, and lift it to a suitable place.

[0083] (4) Check and clean the groove of the large four-way steel ring. After confirming that it is intact, apply grease to the intact steel ring and put it into the groove.

[0084] (5) Before hoisting the main equipment, check and confirm that the rigging is dedicated and the lifting points are intact. The person in charge of the hoisting operation should hold a valid hoisting command certificate and wear a clearly visible identification. During the hoisting process, relevant hoisting operation regulations should be strictly observed to prevent collisions, squeezing, and scratches.

[0085] (6) If there are high-voltage lines on site, the power should be cut off first. If the power cannot be cut off during hoisting, a safe distance should be maintained.

[0086] (7) Install the special rigging on the special lifting lugs of the main body of the confined well site operation device. Tie the traction rope to the lower end of the support frame, and direct the crane to slowly lift the entire device and align it with the wellhead four-way, and lower it smoothly. During the hoisting process, no one is allowed to stand in the direction of the device's movement or within the fall range.

[0087] (8) After inserting the bolts into the four-way connector and supporting the main device, personnel enter the area below the main device to tighten the bolts.

[0088] (9) Tighten the connecting bolts between the device and the wellhead four-way connector diagonally and fully, ensuring even tension at both ends. During installation, the crane should always keep the rope sling taut but not under load to protect the device from tilting.

[0089] (10) After the main equipment is installed, the widened platform, mast, slide, and other equipment are hoisted to the designated positions on the platform using slings, and the operators secure them with pins. Then the rigging is removed, and the operators descend to the ground via a ladder.

[0090] (11) Before operating the restricted well site operation equipment, the main equipment should be inspected again according to the wellhead condition of the construction well, and the support should be reinforced if necessary to prevent the wellhead equipment from being damaged by swaying and vibration during operation.

[0091] (12) After the main equipment for live operation is installed, adjust the auxiliary outriggers to make the mast, the moving slip assembly, and the fixed slip assembly coaxial with the wellhead.

[0092] (13) Install other auxiliary equipment and facilities, and connect hydraulic control lines. The well control devices such as hydraulic lines, blowout preventer assemblies, and manifolds pass pressure testing.

[0093] Through rational design and optimization of the equipment structure, the installation process of the restricted well site operation device of this invention can complete well workover operations in restricted well sites with a floor area of ​​50m2 and a minimum distance of 3m from obstacles. Furthermore, this process is designed to use a single mast for lifting and lowering, with a full mast extension length of 15m. In operation, the extension length can be automatically adjusted according to the restricted height of the well site, with a minimum length of 5m, demonstrating strong applicability.

[0094] II. Hydraulic Lifting Process for Lowering the Tubing Column

[0095] 1. Procedure for raising the tubing string:

[0096] (1) Close the moving load-bearing slip and confirm that the load-bearing slip is in a completely closed state. Load transfer: slowly lift the oil cylinder to concentrate the weight of the tubing onto the moving load-bearing slip.

[0097] (2) Open the fixed clip.

[0098] (3) Lift the tubing string up so that the tubing moves up together with the moving load-bearing slips.

[0099] (4) Close the fixed slips and calculate the position of the lower oil pipe joint to avoid the fixed slips getting stuck on the joint.

[0100] (5) Load transfer: Lower the tubing and visually monitor the weight gauge until the pointer reading is completely released. At this point, the weight of the tubing is transferred to the fixed slips.

[0101] (6) Open the movable load-bearing clamp.

[0102] (7) Lower the hydraulic cylinder so that the moving load-bearing slip is near the lower limit of the hydraulic cylinder.

[0103] (8) Close the movable load-bearing clamp.

[0104] (9) There is a difference in diameter at the fixed slip (tools such as tubing hanger, variable thread, tubing joint clamp, tubing short section clamp, packer, water distributor, etc.).

[0105] (10) Use hydraulic pliers to unscrew the oil pipe. Follow the principle of slow gear first and then fast gear. Only after the threads are completely loosened can the oil pipe be lifted.

[0106] (11) After uncoupling, the oil pipes are sent to the pipe bridge along the slide and the oil pipes are arranged in groups of ten.

[0107] (12) When hoisting downhole tools and the last few tubing sections, the hoisting speed should be less than or equal to 5 m / min to prevent scraping or hitting the wellhead and causing the tools and tubing to fall into the well. During the tubing hoisting process, the operator should pay attention to changes in the load value.

[0108] (13) When closing the slips, observe the closed state of the slips to ensure that the tubing string is clamped. When opening the slips, prepare the load transfer in advance to prevent the tubing string from falling into the well.

[0109] 2. Procedure for lowering the tubing string:

[0110] (1) Use a winch to lift the tubing, which is to be inserted into the well, from the ground to the working platform.

[0111] (2) Lower the winch wire rope so that the oil pipe enters the annular blowout preventer and the fixed slip in sequence.

[0112] (3) Close the fixed load-bearing slips to hold the oil pipe.

[0113] (4) Loosen the winch wire rope.

[0114] (5) The hydraulic cylinder of the upward working machine keeps the moving load-bearing slip at a certain height.

[0115] (6) Close the movable load-bearing clamp.

[0116] (7) Load transfer: Lift the tubing column to concentrate the weight of the tubing column onto the moving load-bearing slip.

[0117] (8) Open the fixed clip.

[0118] (9) The machine moves down to near the bottom of the hydraulic cylinder.

[0119] (10) Close the fixed clip.

[0120] (11) Load transfer: Downward pressure tubing.

[0121] (12) Open the movable load-bearing clamp.

[0122] (13) Repeat the operation steps 4.3.5-4.3.12 to lower the tubing into the well one after another.

[0123] This invention revolutionizes the tubing string raising and lowering process, breaking away from traditional well workover operations. It incorporates a mast system and changes the single-string connection process, using a hydraulic winch on the mast to raise and lower individual tubing strings. A combination of floating load-bearing slips and fixed bidirectional slips is employed to lift and lower the tubing string, eliminating the need for manual removal and reattaching of lifting rings during construction, effectively reducing worker workload. Furthermore, the invention utilizes conical bidirectional slips and a sealed bidirectional slips structure, along with a slips interlocking system, to enhance the safety of the hydraulic lifting and lowering of the tubing string, preventing quality accidents caused by misoperation.

[0124] III. Cyclic Operation Process Procedures

[0125] (1) Lower the tubing column to the predetermined position, connect the inlet and outlet pipelines and the faucet, close the annular blowout preventer to the appropriate pressure, start the pump to circulate, and after the return liquid is normal, use the alternating method of moving load-bearing slips / fixed slips to lower the tubing column at a uniform speed. During circulation, the discharge volume should meet the construction requirements.

[0126] (2) Each time a single tube is flushed, it should be fully circulated, and the well flushing time should be no less than 15 minutes. The time for replacing a single tube should be controlled within 3 minutes. After flushing five tubes in a row, the well should be thoroughly flushed and circulated once before flushing can continue.

[0127] (3) Wellhead staff and pump truck personnel should work closely together, with a designated person to observe pump pressure and outlet return. It is strictly forbidden to flush down a single shaft when leakage is severe or circulation has not been established.

[0128] (4) If the pump truck malfunctions and the pump needs to be stopped, the tubing string should be raised to more than 100m above the original sand surface; for sand flushing in composite casing, it should be raised above the hanger; for sand flushing in horizontal wells, it should be raised above the horizontal section; and the tubing string should be moved repeatedly. When the mobile hoisting system malfunctions, the well should be thoroughly circulated and flushed.

[0129] (5) After flushing the sand to the bottom of the artificial well or the designed depth, the pump truck should maintain a discharge rate of more than 25 m3 / h for complete circulation. The sand flushing is considered qualified when the sand content at the outlet is less than 0.2%. Then, raise the tubing to 100 m above the original sand surface, allow it to settle for the designed time, and then re-examine the sand surface and record the depth.

[0130] When used in conjunction with an annular blowout preventer (BOP), it can seal the annulus of the oil casing, meeting the needs of cyclic operation and enabling sand flushing, drilling, and other operations. Simultaneously, when drilling and grinding shallow ash plugs are performed, if abnormally high pressure occurs in the well, closing the annular BOP and moving the top slip can effectively prevent tubing from coming out, avoiding personnel injury and equipment damage.

[0131] IV. Salvage and Unblocking Process Procedures

[0132] (1) Select appropriate fishing tools (preferably retractable ones) based on the fish situation in the well, and measure the tool's length, inner diameter, and outer diameter, and take photos of the tool. Check the integrity of each component of the downhole tool and lower the drill string to the predetermined position.

[0133] (2) If the retrieval is blocked, the movable tubing string should be released, but the allowable load of the equipment and the retrieval tubing string must not be exceeded, and the retrieval tubing string must be thickened.

[0134] (3) When the pipe column is released, the movable anti-top and movable load-bearing slips should be closed at the same time to prevent the pipe column from accidentally moving upward and causing mechanical damage.

[0135] (4) If the lifting force does not meet the construction requirements when releasing the card, the overflow valves of the two lifting cylinders can be adjusted. The pressure adjustment of the lifting cylinder system is set at 7.5MPa. When used for releasing the card, the pressure shall not exceed 15MPa. When the working pressure is 15MPa, the lifting force is 80T and the pulling force is 45T; when it is 10MPa, the lifting force is 53T and the pulling force is 30T; when it is 7.5MPa, the lifting force is 40T and the pulling force is 23T; when it is 5MPa, the lifting force is 26T and the pulling force is 15T.

[0136] (5) If the activity card is not opened, choose to withdraw the salvage tool or pull out the salvage string upside down according to the actual situation.

[0137] The device is designed with four lifting cylinders, with a maximum lifting stroke of 2.5m and a maximum lifting force of 650kN. After lowering the retrieval tool and retrieving the fallen object, the movable load-bearing slip is closed to lift the tubing string. The movable anti-top slip is closed to prevent the tubing string from being pushed up after being unstuck. Compared with conventional major and minor repairs, the device provides greater safety for retrieval and unstuck operations in restricted well sites.

[0138] V. Rotation Operation Procedures

[0139] (1) Inspect the integrity of the turntable to ensure it is flexible and easy to use.

[0140] (2) Lower the drill string to the predetermined position and connect the inlet and outlet pipelines, as well as the faucet and hose.

[0141] (3) Lower the tool to the predetermined position, close the annular blowout preventer, and start the pump to circulate until the liquid properties at the inlet and outlet are consistent.

[0142] (4) Simultaneously close the movable load-bearing slip and the movable anti-top slip to prevent the pipe column from moving upward.

[0143] (5) Remove the hydraulic lines of the movable anti-top clamps and movable load-bearing clamps, and connect the hydraulic lines of the turntable.

[0144] (6) Start the turntable, slowly lower the tubing, pressurize to (5-10) KN, and the annular return speed is not less than 0.8 m / s.

[0145] (7) When the moving slip falls to the lowest point, stop the turntable from rotating, connect the moving anti-top slip and the moving load-bearing slip pipeline, close the fixed slip, open the moving load-bearing slip and the moving anti-top slip, raise the oil cylinder to the upper end, repeat steps 4.2.4-4.2.7, and slowly drill the oil pipe to the predetermined position.

[0146] Using a hydraulic rotary table and a slip mechanism, the oil pipe can be clamped and rotated without the need for other equipment such as square drill rods, power swivels, or screw drills. This allows for rotary operations such as drilling, grinding, backing, and milling, making construction simpler.

[0147] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention within the scope of the technology disclosed in the present invention, and can also make simple deductions and substitutions without departing from the concept of the present invention. All such substitutions and modifications should be covered within the scope of protection of the present invention.

Claims

1. A restricted wellsite workover operation process, characterized in that, The process steps are as follows: S1, install the limited well site workover operation device; S2, execute the hydraulic lifting pipe string operation process; S3, execute the circulation operation process; S4, execute the fishing and unjamming process; S5, execute the rotating operation process.

2. The limited wellsite workover process of claim 1, wherein, In the step S1, the limited well site workover operation device installation process steps are as follows: S11, wash or kill the well until the wellhead is in a no overflow state; S12, check and clean the blowout preventer steel ring groove, and check whether the gate is flexible to open and close; S13, remove the original wellhead large four-way flange bolts, and remove the original wellhead flange and the upper part thereof using standard rigging; S14, check and clean the large four-way steel ring groove, confirm that it is intact, and then apply butter to the intact steel ring and put it into the steel ring groove; S15, hoist the main device of the limited well site workover operation device, check and confirm that the rigging is special, and that the equipment lifting point is intact; install the rigging on the special lifting lug of the main device of the limited well site workover operation device, bind the traction rope at the lower end of the support frame, and slowly hoist the device as a whole by the crane, align it with the wellhead four-way, and then slowly lower it; S16, after the bolts are inserted into the four-way, support the main device, and then personnel enter below the main device to tighten the bolts; S17, diagonally tighten the connecting bolts between the main device and the wellhead four-way, and fully tighten the bolts, with the remaining nuts being uniform at both ends; S18, after the main device is installed, use lifting belts to hoist the widened platform, mast, and slide to the designated positions on the platform, and then use a latch to fix them; install the auxiliary equipment and facilities, connect the hydraulic control pipeline, and determine that the hydraulic pipeline, blowout preventer group, and manifold are qualified after pressure test.

3. The confined wellsite workover operation process of claim 2, wherein, Before the operation of the limited well site operation device, the main device is checked again according to the wellhead condition of the construction well, and the support is further reinforced to prevent damage to the wellhead device due to shaking and vibration during the operation.

4. The confined wellsite workover operation process of claim 2, wherein, After the installation of the underbalanced operation main device is completed, the auxiliary support legs are adjusted to make the mast, traveling slips group, and fixed slips group coaxial with the wellhead.

5. The confined wellsite workover operation process of claim 1, wherein, In the step S2, the pipe string lifting steps are as follows: S21, close the traveling load bearing slips, confirm that the load bearing slips are in a completely closed state, and transfer the load: slowly raise the oil cylinder to concentrate the weight of the pipe string on the traveling load bearing slips; S22, open the fixed slips; S23, raise the pipe string to make the tubing go up with the traveling load bearing slips; S24, close the fixed slips, and measure the position of the lower tubing joint to avoid the fixed slips from clamping the joint; S25, load transfer: lower the pipe string, visually observe the load indicator, and stop when the pointer reading is completely released, at which time the weight of the pipe string is released to the fixed slips; S26, open the traveling load bearing slips; S27, lower the oil cylinder to make the traveling load bearing slips near the lower stop point of the oil cylinder; S28, close the traveling load bearing slips; S29, there are different diameter tools in the fixed slips; S210, use the hydraulic tongs to remove the tubing threads, and according to the principle of slow first and then fast, the tubing can be lifted only after all the threads are loosened; S211, the tubing after the buckle is sent to the pipe bridge along the slide.

6. The limited wellsite workover process of claim 5, wherein, When the downhole tool and the last few pipes are lifted, the lifting speed is slowed down to prevent scratching, bumping the wellhead, causing the tool and pipe string to fall into the well; During the pipe string lifting process, the operator should pay attention to the change of load value; When closing the slips, observe the slip closing state to ensure that the pipe string is clamped, and when opening the slips, the load transfer should be done in advance to prevent the pipe string from falling into the well.

7. The confined wellsite workover operation process of claim 5, wherein, In step S29, the reducing tool includes one or more of a tubing hanger, a variable buckle, a tubing joint clamp, a tubing short joint clamp, a packer, and a water distributor.

8. The confined wellsite workover operation process of claim 1, wherein, In step S2, the pipe string lowering process is as follows: S21, use the winch to lift the prepared pipe into the well to the working platform from the ground; S22, lower the winch wire rope to make the pipe enter the annular blowout preventer and the fixed slips in turn; S23, close the fixed load-bearing slips to hold the oil; S24, loosen the winch wire rope; S25, make the mobile load-bearing slip cylinder ascend to a certain height; S26, close the mobile load-bearing slip; S27, load transfer: lift the pipe string to concentrate the weight of the pipe string on the mobile load-bearing slip; S28, open the fixed slip; S29, lower the operating machine to the lower stop point of the cylinder; S210, close the fixed slip; S211, load transfer: press down the pipe string; S212, open the mobile load-bearing slip; S213, repeat the operation steps S21-S212 to lower the pipes into the well one by one.

9. The confined wellsite workover operation process of claim 1, wherein, In step S3, the circulating operation process is as follows: S31, lower the pipe string to the predetermined position, connect the inlet and outlet pipelines and the faucet, close the annular blowout preventer, start the pump to circulate, and after the return fluid is normal, use the mobile load-bearing slip / fixed slip alternation method to lower the pipe string at a constant speed; S32, each time the pipe string is flushed, it is fully circulated; after continuously flushing several single pipes, it is necessary to thoroughly circulate for a week before continuing to flush; S33, the wellhead staff and the pump truck cooperate closely to observe the pump pressure and outlet return fluid.

10. The limited wellsite workover process of claim 9, wherein, If the pump truck fails and needs to be repaired, lift the pipe string away from the original sand face; flush the composite casing to above the hanger; flush the horizontal well to above the horizontal section; and repeatedly move the pipe string. When the traveling hoisting system fails, thoroughly circulate the well.

11. The confined wellsite workover operation process of claim 1, wherein, In step S4, the fishing and unjamming process steps are as follows: S41, select appropriate fishing tools according to the fish in the well, measure the tool length, inner diameter, and outer diameter, and take photos of the tools; check the integrity of the downhole tools, and lower the drilling tool to the predetermined position; S42, if the fishing tool is stuck after fishing, move the pipe string to unjam, but do not exceed the allowable load of the equipment and the fishing pipe string, and the fishing pipe string must use thick-walled tubing; S43, when moving to unjam, the mobile anti-top slip and the mobile load-bearing slip should be closed at the same time to prevent the pipe string from unexpectedly rising and causing mechanical damage; S44, if the lifting force does not meet the construction requirements when unjamming, adjust the overflow valve of the lifting cylinder, and set the pressure of the lifting cylinder system; S45, if the unjamming is not successful, select to withdraw the fishing tool or reverse the buckle to lift the fishing pipe string according to the actual situation.

12. The confined wellsite workover operation process of claim 1, wherein, In step S5, the rotating operation process steps are as follows: S51, check the integrity of the rotating disc to ensure flexibility and good use. S52, lower the drilling tool to the predetermined position, connect the inlet and outlet pipelines and the faucet and water hose; S53, lower the tool to the predetermined position, close the annular blowout preventer, and open the pump for positive circulation to make the inlet and outlet liquids consistent; S54, simultaneously close the mobile load slips and the mobile backoff slips to prevent the pipe string from upward movement.

13. The limited wellsite workover process of claim 12, wherein, The step S5 further comprises the following steps: S55, remove the mobile backoff slip and the mobile load slip hydraulic pipelines, and connect the rotary table hydraulic pipelines; S56, start the rotary table, slowly lower the pipe string, pressurize, and return upward in the annulus; S57, when the mobile slip falls to the lowest end, stop the rotary table rotation, connect the mobile backoff slip and the mobile load slip pipelines, close the fixed slip, open the mobile load slip and the mobile backoff slip, raise the oil cylinder to the upper end, repeat the steps S54-S57, and slowly drill the oil pipe to the predetermined position.

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