CN217055061U - Equipment suitable for operation is pressed in shallow low pressure oil well area - Google Patents

Abstract

The utility model discloses equipment suitable for the operation under pressure of a shallow low-pressure oil well, in particular to equipment suitable for the operation under pressure of a shallow low-pressure oil well, which comprises a well repairing system, an operation under pressure power source system and accessory equipment; the under-pressure operation machine comprises a main body, a frame, an upper platform, an overhead operation platform, a lifter system and an active turntable; the main part from the bottom up includes half closed ram preventer of lower work, balanced pressure release system, half closed ram preventer of upper work, work annular preventer, fixed slips group, the slips group that moves about in proper order. The utility model discloses an operation machine is pressed to area is sled dress auxiliary type and is pressed operation device, has compact structure, light in weight, the characteristics of being convenient for maintain.

Description

Equipment suitable for operation is pressed in shallow low pressure oil well area

Technical Field

The utility model belongs to oil well exploitation equipment field especially relates to an equipment suitable for operation is pressed in shallow low pressure oil well area.

Background

The traditional well repairing means is that the high-density well-killing hydraulic well or open flow is firstly utilized to achieve the purpose of reducing the pressure in the well, and then well repairing operation is carried out. The high pressure fluid used during the application of pressure creates a certain fusion effect with some of the formation minerals in the reservoir. Therefore, the geological environment of the energy storage layer can be damaged, liquid and rock soil can react, the geological environment of an oil-gas production layer is turbid, oil sludge at the bottom layer of an oil well is blocked, the permeability of the liquid is reduced, and the like, and the production rate of the oil well is finally reduced. This makes the oil and gas output of our country reduce constantly, especially to the influence of horizontal oil and gas exploitation well and natural gas exploitation well extremely serious. The killing operation can block an underground oil-water pipeline, so that the water injection effect and the recovery yield are influenced, and the killing operation has high cost, long time and heavy pollution; blowout depressurization can cause a large amount of overflow of formation pressure, which damages the internal structure of the formation and the pressure distribution of an oil well network and causes immeasurable loss for future production. Well killing and blowout operation modes are not beneficial to sustainable development of oil and gas resources, and brand new well repairing operation modes are needed to protect the oil resources in China.

The traditional well repairing means has the following disadvantages:

first, in conventional operation, a high pressure well is first pumped to balance the formation pressure, and the well control fluid enters the formation more or less, which prevents the occurrence of a blowout but causes contamination of the formation. Thereby having an unavoidable influence on the geological analysis. Links such as follow-up data recording, oil testing, well completion operation and the like are adversely affected, so that the result of oil reservoir description is deviated, and the recovery efficiency is affected.

Secondly, killing a gas well with a thicker gas layer, wherein the stratum pressure outlet of the gas well is too small, and if a puncture accident is caused by killing the well, well fluid overflows without killing the well, so that the safe operation condition cannot be guaranteed; low permeability gas wells are easily crushed.

Thirdly, the damage of the well killing operation to the stratum environment is obvious, the cost of the well killing fluid is considerable, and the well killing fluid needs to be pumped and discharged after the operation is finished. When the water well is operated, the water well stops injecting and pressure releasing time is long, and peripheral water wells also need to stop injecting in order to keep the formation pressure field balanced, so that the production of the oil well is reduced or stopped, and the production is seriously influenced.

The existing oilfield pressurized workover equipment has the characteristics that:

the sealing pressure is high, and the sealing device is in super-performance configuration relative to a low-pressure shallow gas well and is poor in economical efficiency. Because the oil field operation under pressure is mostly suitable for high-yield wells and key wells, the pressure of the wells is high, and the contradiction between layers is prominent, the sealing pressure is required to be high when the operation under pressure is carried out, the holding force between a blowout preventer and a pipe column is large, and the passing of a tubing coupling is difficult.

② the structure is complex and the volume is large. In order to ensure high-pressure sealing in operation and increase the operation reliability, a plurality of blowout preventers are required to be matched for operation, so that the whole structure of the equipment is complex, the equipment is stacked, the volume of pressurized workover equipment is increased, and the operation is complex.

And thirdly, the operation period is long. In the well workover treatment under pressure, through moving about the slips, fixed slips and lifting oil cylinder alternative operation through the tubing coupling, it rises to compare in the hook of conventional trip block, and the required time overlength. Meanwhile, due to the fact that the equipment is complex to operate, the operation efficiency is reduced, and the operation time is prolonged.

Because the conventional oil field pressurized operation equipment is designed based on reservoir characteristics such as high pressure, deep well and the like of a conventional oil and gas well, the conventional oil and gas well pressurized operation equipment is not suitable for direct introduction in low-pressure shallow pressurized workover and mainly shows that:

firstly, the operation equipment is not matched. The conventional pressurized workover equipment is suitable for high-yield wells with large pressure and deep burial, the well head of a low-pressure shallow gas well has lower pressure, the required well shut-in pressure is low, and the operation cost is increased by applying the conventional pressurized workover equipment. .

And the operation time is long. The forced tripping operation of the oil-gas field under pressure adopts a hydraulic cylinder to lift, each oil pipe needs to be circulated for at least 3 times averagely, the operation time is long, water is continuously produced in a reservoir, the pressure increment of the well bottom is continuously increased, the 'actual well killing' is caused, and the productivity of a gas well is influenced.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an equipment suitable for operation is pressed to shallow low pressure oil well area to solve the long technical problem of present operation equipment non-corollary and activity duration.

In order to solve the technical problem, the specific technical scheme of the utility model as follows:

the equipment suitable for the operation under pressure of the shallow low-pressure oil well comprises a well repairing system, an operation under pressure power source system and accessory equipment;

the workover system completes workover operation and is matched with the pressurized operation system to complete forced lifting and lowering operation of the pipe column;

the under-pressure operation system comprises a pressure testing cross, a safe full-sealing ram blowout preventer, a wellhead stabilizer, a safe semi-sealing ram blowout preventer and an under-pressure operation machine from bottom to top; the pressure testing cross, the safe full-sealing ram blowout preventer, the well mouth stabilizer, the safe semi-sealing ram blowout preventer and the pressurized operation machine are connected with one another sequentially through flanges;

the under-pressure operation machine comprises a main body, a frame, an upper platform, an overhead operation platform, a lifter system and an active turntable;

the main body sequentially comprises a lower working semi-closed ram blowout preventer, a balance pressure relief system, an upper working semi-closed ram blowout preventer, a working annular blowout preventer, a fixed slip group and a moving slip group from bottom to top;

the working annular blowout preventer can seal tools of any shapes and realize zero sealing in emergency situations;

the balance pressure relief system is used for balancing or relieving the pressure in the working annular blowout preventer and the working single-ram blowout preventer;

the fixed slip group is arranged on the working annular blowout preventer and is matched with the floating slip group to finish the operation of pulling up and pulling down the oil pipe;

the frame comprises a lower platform and an upright post; a lower substrate is arranged on the lower platform;

the upper platform and the high-altitude operation platform comprise an upper platform and a high-altitude driller platform;

the upper platform comprises an upper base plate, a main pedal guardrail and a driller platform;

the driller platform is fixed at one side corner of the main pedal, the guardrail of the main pedal is arranged at the edge of the main pedal, and the upper base plate extends out of the central through hole of the main pedal;

the upright posts are connected with the upper substrate and the lower substrate;

the lifter system comprises a lifting hydraulic cylinder and a control valve group; the lifting hydraulic cylinder is connected with the control valve group through a hydraulic pipeline;

the upper substrate and the lower substrate are respectively connected to the upper end and the lower end of the lifting hydraulic cylinder;

the high-altitude driller platform is fixed on the upper platform.

Further, the balanced pressure relief system comprises: balance pressure relief four-way, manual plug valve, hydraulic plug valve and wellhead pressure gauge.

Furthermore, hydraulic buffer structures are designed at the upper and lower end points of the lifting hydraulic cylinder, so that the lifting hydraulic cylinder moves stably; the control valve group uses a high-flow control valve.

Furthermore, the driving turntable is designed with a mechanical locking device.

Further, the well repair system comprises a derrick, a crown block, a traveling block and a winch.

Further, the working annular blowout preventer is configured with a buffer accumulator.

Furthermore, the pressurized operation power source system comprises a hydraulic pump, a hydraulic circuit, a circuit system and a gas circuit system.

Furthermore, the upper platform also comprises an upper platform accessory, and the upper platform accessory comprises a lower oil pipe steel wire rope fixing rod, a falling protector fixing rod, an escape device fixing rod and a hydraulic clamp tail rope fixing rod which are vertically arranged on the main pedal.

Furthermore, the equipment accessories comprise a coupling detector, a telescopic protection ladder stand, a host machine transportation pry, a hoisting hanger and a hydraulic pipeline;

the coupling detector comprises a coupling detector shell and a coupling detector component; the coupling detector component is installed inside the coupling detector shell, the coupling detector is installed between a safe semi-closed ram blowout preventer and a lower working semi-closed ram blowout preventer, the telescopic protective ladder is hung at the upper platform, the host machine transportation pry is used for horizontally and fixedly placing the operation machine under pressure, the hoisting sling is installed at the hoisting point of the operation machine under pressure, and the hydraulic pipeline is used for connecting the operation power source system under pressure and the operation machine under pressure to play the role of transmitting hydraulic power.

The utility model discloses an equipment suitable for operation is pressed in shallow low pressure oil well area has following advantage:

1. the utility model discloses be equipped with flashboard preventer, remove slips group, fixed slips group and coupling detector, the tubular column that various specifications can be solved to not unidimensional removal slips group, fixed slips group prevents spouting the problem, provides reliable centre gripping assurance for lifting the tubular column and transferring the tubular column operation. The ram blowout preventer can meet the sealing problem of tubular columns with various specifications. The coupling detector can detect the position of a coupling and can smoothly pass through the coupling, so that effective guarantee is provided for the pipe column to be pulled up and down.

2. The utility model discloses with the workover system of the equipment of operation is pressed to shallow low pressure oil well area and press operation power source system to combine organically, can provide required hydraulic power for workover system and area pressure operation system simultaneously.

3. The utility model discloses utilize the quick-witted system of lifting of area pressure workover rig and workover system hook complex operation mode to lift, transfer the tubular column.

4. The utility model discloses an operation machine is pressed to area is sled dress auxiliary type and is pressed operation device, has compact structure, light in weight, the characteristics of being convenient for maintain.

Drawings

Fig. 1 is a schematic view of the working state of the operation equipment under pressure of the present invention;

FIG. 2 is a schematic view of the structure of the operation system under pressure according to the present invention;

FIG. 3 is a diagram of the working state of the pressurized working equipment of the present invention;

fig. 4 is a loading diagram of the working machine under pressure of the present invention;

fig. 5 is a state diagram of the operation equipment under pressure of the utility model;

fig. 6 is a schematic structural view of an upper platform of the belt press working machine of the present invention;

FIG. 7 is a schematic view of the coupling detector of the present invention;

FIG. 8 is a schematic view of a first side member of the coupling detector of the present invention;

FIG. 9 is a schematic view of a second side member of the coupling detector of the present invention;

the symbols in the figure illustrate: 1. four-way pressure test; 2. a safe full seal ram blowout preventer; 3. a wellhead stabilizer; 4. a safety semi-closed ram blowout preventer; 5. an upper working semi-closed ram blowout preventer; 6. a lower working semi-closed ram blowout preventer; 7. a working annular blowout preventer; 8. a balanced pressure relief system; 9. fixing a slip set; 10. a traveling slip set; 11. lifting the hydraulic cylinder; 12. an upper substrate; 13. a lower substrate; 14. an upper platform; 15. a driller's stand; 16. pulling out the tubing steel wire rope fixing rod; 17. an escape device fixing rod; 18. a hydraulic tong tail rope fixing rod; 19. a collar detector; 20. the telescopic protective ladder stand; 21. a power source system for operation under pressure; 22. the host machine is transported and pried; 23. a collar detector housing; 24. a collar detector component; 25. detecting a roller; 26. detecting a plunger; 27. a probe component housing; 28. pre-pressing a spring; 29. adjusting the piston; 30. plugging with a thread; 31. a limiting ring; 32. a seal member; 33. a displacement transfer rod of the sensor mechanism; 34. a displacement transfer guide block; 35. a sensor holder; 36. a proximity displacement sensor; 37. a lifter system.

Detailed Description

In order to better understand the purpose, structure and function of the present invention, the following figures are combined to further describe the device for the operation under pressure in shallow low pressure well.

As shown in fig. 1, 3 and 5, the utility model relates to a device suitable for shallow low-pressure oil well operation under pressure, which comprises a workover system, an operation system under pressure, an operation power source system 21 under pressure and accessory equipment;

the workover system completes workover operation and is matched with the pressurized operation system to complete forced lifting and lowering operation of the pipe column; the well repairing system comprises a derrick, a crown block, a traveling block and a winch.

The pressurized operation power source system 21 comprises a hydraulic pump, a hydraulic loop, a circuit system and an air path system.

The pressurized operation system comprises a pressure testing cross 1, a safe full-sealing ram blowout preventer 2, a wellhead stabilizer 3, a safe semi-sealing ram blowout preventer 4 and a pressurized operation machine from bottom to top; the pressure testing cross 1, the safe full-seal ram blowout preventer 2, the wellhead stabilizer 3, the safe half-seal ram blowout preventer 4 and the operation machine under pressure are sequentially connected with one another through flanges;

as shown in fig. 2, 4 and 6, the operation machine with pressure comprises a main body, a frame, an upper platform, an overhead operation platform, a lifter system 37 and a driving turntable;

the main body sequentially comprises a lower working semi-closed ram blowout preventer 6, a balance pressure relief system 8, an upper working semi-closed ram blowout preventer 5, a working annular blowout preventer 7, a fixed slip group 9 and a moving slip group 10 from bottom to top;

the working annular blowout preventer 7 can seal tools of any shape and achieve zero sealing in emergency situations; the working annular blowout preventer 7 is equipped with a buffer accumulator, and the hydraulic system can maintain a constant pressure when the outer diameter of the pipe string changes.

The balance pressure relief system 8 is used for balancing or relieving the pressure in the working annular blowout preventer 7 and the working single ram blowout preventer, and the purpose of protecting rubber parts of the ram blowout preventer and workers is achieved. The balanced pressure relief system 8 comprises: balance pressure relief four-way valve, manual plug valve, hydraulic plug valve and well head pressure gauge. The wellhead pressure gauge is used for displaying the pressure of the shaft.

The fixed slip group 9 is arranged on the working annular blowout preventer 7 and is matched with the floating slip group 10 to finish the operation of pulling up and pulling down an oil pipe;

the frame comprises a lower platform and an upright post; a lower substrate 13 is arranged on the lower platform;

the upper platform and the high-altitude operation platform comprise an upper platform 14 and a high-altitude driller platform;

the upper platform 14 comprises an upper base plate 12, a main pedal guardrail and a driller's stand 15;

the driller's platform 15 is fixed at one side corner of the main pedal, the guardrail of the main pedal is arranged at the edge of the main pedal, and the upper base plate 12 extends out of the central through hole of the main pedal.

The upper platform 14 further comprises an upper platform accessory, and the upper platform accessory comprises a lower oil pipe steel wire rope fixing rod 16, a falling protector fixing rod, an escape device fixing rod 17 and a hydraulic clamp tail rope fixing rod 18 which are vertically arranged on the main pedal.

The upright posts are connected with an upper substrate 12 and a lower substrate 13.

The lifter system 37 comprises a lifting hydraulic cylinder 11 and a control valve group; the lifting hydraulic cylinder 11 and the control valve group are connected by a hydraulic pipeline; hydraulic buffer structures are designed at the upper and lower end points of the lifting hydraulic cylinder 11, so that the lifting hydraulic cylinder 11 can move stably; the control valve group uses a large-flow control valve

The upper substrate 12 and the lower substrate 13 are respectively connected to the upper end and the lower end of the lifting hydraulic cylinder 11;

the high-altitude driller's stand is fixed to the upper platform 14. The control objects are as follows: the device comprises units such as a lifting hydraulic cylinder 11, a balance valve, a pressure release valve, an upper working semi-closed ram blowout preventer 5, a lower working semi-closed ram blowout preventer 6, a working annular blowout preventer 7, a fixed slip group 9, a floating slip group 10, an active rotary table and the like. All valves are mounted on a control panel, and each pressure gauge is arranged on the other vertical surface. The high-altitude driller console can remotely control the rotating speed of the diesel engine and forcibly shut down the operation.

The high-altitude driller platform also comprises a display instrument, wherein the display instrument comprises a torque meter, a shaft pressure gauge, an upward lifting pressure gauge, a downward pressure gauge, a system pressure gauge, an annular pressure gauge, a flashboard closing pressure gauge, a slip group pressure gauge and the like.

The driving rotary table is used for drilling and grinding or back-off and butt-joint operation under pressure. A mechanical locking device is designed, and the locking device is locked when the active rotary disc is not used, so that people can be prevented from being injured by misoperation.

The pressure operation power source system is used for providing hydraulic power for the pressure operation machine. The pressurized operation power source system is driven by a workover rig diesel engine.

The power source system for operation under pressure comprises a hydraulic pump, a hydraulic loop, a circuit system and a gas circuit system. The maximum pressure of all hydraulic circuits is 21Mpa, the pipe diameter design meets the requirements of the displacement of the hydraulic pump and the working capacity of an actuating element, the pipeline layout is neat and attractive, the serial number arrangement is realized, and the maintenance and the replacement are convenient. All external hydraulic lines gather to a hydraulic pressure joint panel on, mark the joint usage on the panel to adopt not unidimensional quick-operation joint and dust cover, be convenient for external manifold to connect. The electric element meets the explosion-proof technical requirement. The circuit system is provided with a grounding device, the grounding resistance is less than or equal to 10 ohms, and all the electrical elements are provided with circuit breakers. The working neutral line must not be taken as a ground line.

The gas path system is provided with a filtering, drying and draining device. The remote throttle adjusting and emergency cut-off functions can be realized.

As shown in FIG. 7, the collar detection device is composed of a collar detector housing 23 and a collar detector element 24, wherein the collar detector housing 23 is a carrier of the collar detector element 24. The coupling detector member 24 is installed inside the coupling detector housing 23, and the coupling detector housing 23 is installed between the safety semi-ram preventer 4 and the lower working semi-ram preventer 6.

As shown in FIGS. 8 and 9, the collar detector assembly 24 includes a first side member and a second side member. The first side component comprises a detection roller 25, a detection plunger 26, a pre-pressing spring 28, an adjusting piston 29 and a plug 30 from left to right in sequence. A detector component housing 27 is provided on the outside of the detection plunger 26.

The second side component comprises a limiting ring 31, a sealing element 32, a displacement transmission guide block 34 and an approaching displacement sensor 36 from left to right in sequence. The displacement transmission rod 33 of the sensor mechanism is provided above the displacement transmission guide block 34. The sensor holder 35 is disposed near the upper portion of the displacement sensor 36.

In the operation in-process is pressed in the area, when the body of rod passes through the well head along the central axis, because the diameter is less than the distance between the detection gyro wheel 25, can not produce radial effort to detecting gyro wheel 25, and it does not have displacement output to detect plunger 26, and sensor mechanism just can not signals, also does not report to the police. When the tubing coupling passes through the central axis, the diameter of the tubing coupling is increased, so that the tubing coupling contacts the detection roller 25 and pushes the tubing coupling outwards along the radial direction (the axial direction of the detection plunger 26), and the tubing coupling is ensured to pass through a wellhead smoothly along the central axis of an oil well; meanwhile, the collar compresses the pre-pressing spring 28 of the detection plunger 26, so that the detection plunger 26 generates displacement; the displacement is transmitted to the guide block 34 through the displacement transmission rod 33 of the sensor mechanism, enters the detection range of the proximity sensor, and is enabled to send out a detection signal, and meanwhile, sound and light alarm is carried out, so that next operation indication is provided for an operator.

The equipment accessories comprise a coupling detector 19, a telescopic protection ladder stand 20, a host machine transportation pry 22, a hoisting hanger and a hydraulic pipeline;

a telescopic protective ladder 20 is suspended from the upper platform 14 and workers reach the upper platform 14 via the ladder. The main machine transportation pry 22 is used for horizontally and fixedly placing the under-pressure operation machine, the hoisting sling is installed at the hoisting point of the under-pressure operation machine, and the hydraulic pipeline is used for connecting the under-pressure operation power source system 21 and the under-pressure operation machine and plays a role in transmitting the hydraulic power.

The chassis of the host transport pry 22 is provided with a complete machine hoisting lug plate, so that integral hoisting and transportation can be performed.

And after the operation of the tubular column is finished, replacing the semi-closed rams of the upper working semi-closed ram blowout preventer 5 and the lower working semi-closed ram blowout preventer 6 with tubular column semi-closed rams. The collar detector 19 is set to an open position to ensure that the detector element housing 27 is in a full bore position. The pipe column can be lifted under pressure.

For the operation of pulling out and running the tubular column under pressure, a ram type blowout preventer ram and an operation machine slip (the sizes of the ram type blowout preventer ram have various specifications such as phi 16mm, phi 19mm, phi 22mm and the like, and are selected according to the size of the underground tubular column) are researched and processed, wherein the ram type blowout preventer ram is a ram type blowout preventer component which is matched with the size of a construction tubular column, and an annulus between the sealing sleeve and the tubular column is sealed; the slips of the operation machine are fittings of a movable slip group 10 and a fixed slip group 9, are matched with the size of a construction pipe column and are used for clamping and suspending the pipe column; and is matched with a collar detector 19. The operation machine slips without the size can solve the problem of blowout prevention of pipe columns with various specifications, and provide reliable clamping guarantee for the operation of lifting and lowering the pipe columns; the ram plate of the ram preventer which is specially researched and developed can meet the sealing problem of pipe columns with various specifications; the coupling detector 19 not only can detect the position of a coupling, but also can smoothly pass through the coupling, thereby providing effective guarantee for the tripping of the pipe column operation.

Comprises the following steps:

lifting the tubular column:

when the underground pressure is not enough to push the pipe column and the pipe column has no upward fleeing trend, the pipe column is lifted up by using a hook on the workover system, and the process is as follows: closing the balance pressure relief system 8 and the upper working semi-closed ram blowout preventer 5, and lifting the pipe column by a big hook; when the collar detector 19 sends out a sounding signal, the lifting speed of the large hook is suspended or slowed down, the lower working semi-closed ram blowout preventer 6 is closed, the balanced pressure relief system 8 is opened to release blowout, the upper working semi-closed ram blowout preventer 5 is opened, and the pipe column is lifted continuously until the collar is exposed; after the pipe column is dismounted, the operation process is continued to pull out the pipe column below until all the operations are finished;

when pressure makes the tubular column have the trend of scurrying in the pit, adopt the machine system 37 that lifts in the area pressure operation machine to play the pole, workover system hook takes the elevator cooperation to right the tubular column, and its process is as follows: closing a pressure relief system, a traveling slip group 10 and an upper working semi-closed ram blowout preventer 5 in a balanced pressure relief system 8, lifting a hydraulic cylinder 11 by the traveling slip group 10, and opening other components; when the traveling slip group 10 moves to the highest point, the fixed slip group 9 and the lower working semi-closed ram blowout preventer 6 are closed, the balanced pressure relief system 8 is opened to release blowout, the upper working semi-closed ram blowout preventer 5 is opened, the traveling slip group 10 is closed, the fixed slip group 9 is opened, the lifting hydraulic cylinder 11 is made to move downwards, the actions are repeated until a coupling is exposed, a pipe column is taken out by tripping, and the whole pipe column lifting process is completed;

lowering the pipe column:

when the underground pressure is not enough to lower the pipe column and the pipe column has no upward movement tendency, a big hook on the workover system is adopted to lower the rod; the rod descending process is as follows: closing the lower working semi-closed ram blowout preventer 6 and the balanced pressure relief system 8, keeping other components in an open state, allowing the large hook to carry the pipe column to move downwards through the elevator, closing the upper working semi-closed ram blowout preventer 5 and opening the lower working semi-closed ram blowout preventer 6 after the coupling passes through the upper working semi-closed ram blowout preventer 5, and continuing to move downwards; estimating that a coupling passes through the lower working semi-closed ram blowout preventer 6, closing the lower working semi-closed ram blowout preventer 6, and opening the balanced pressure relief system 8 and the upper working semi-closed ram blowout preventer 5 to continue descending; repeating the process until all the pipe columns are completely lowered;

when the underground pressure causes the pipe column to have the upward movement tendency, a lifting hydraulic cylinder (11) of the pressurized operation machine is used for lowering the rod, and a large hook of the workover system carries an elevator to cooperate with the elevator to centralize the pipe column; the process is as follows: firstly, lifting a hydraulic cylinder 11 by a floating slip group 10 to move upwards to the highest point, then closing a balance pressure relief system 8, an upper working semi-closed ram blowout preventer 5 and the floating slip group 10, and keeping other components in an open state; and then, the pipe column is clamped to move downwards along with the lifting hydraulic cylinder 11, when the lifting hydraulic cylinder 11 moves downwards to the lowest position, the lower working semi-closed ram blowout preventer 6 and the fixed slip set 9 are closed, the balanced pressure relief system 8, the upper working semi-closed ram blowout preventer 5 and the floating slip set 10 are opened, the lifting hydraulic cylinder 11 moves upwards to the highest point, and the process is repeated until all the pipe columns are completely moved downwards.

It is to be understood that the present invention has been described with reference to certain embodiments, and that various changes or equivalents may be substituted for elements thereof by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are intended to be covered by the present invention.

Claims (9)

1. The equipment suitable for the operation under pressure of the shallow low-pressure oil well is characterized by comprising a well repairing system, an operation under pressure power source system (21) and accessory equipment;

the workover system finishes workover operation and is matched with the pressurized operation system to finish forced lifting and lowering operation of the tubular column;

the under-pressure operation system comprises a pressure testing cross joint (1), a safe full-sealing ram blowout preventer (2), a wellhead stabilizer (3), a safe semi-sealing ram blowout preventer (4) and an under-pressure operation machine from bottom to top; the pressure testing cross joint (1), the safe full-sealing ram blowout preventer (2), the well mouth stabilizer (3), the safe semi-sealing ram blowout preventer (4) and the operation machine with pressure are sequentially connected with one another through flanges;

the operation machine with pressure comprises a main body, a frame, an upper platform, an overhead operation platform, a lifter system (37) and a driving turntable;

the main body sequentially comprises a lower working semi-closed ram blowout preventer (6), a balance pressure relief system (8), an upper working semi-closed ram blowout preventer (5), a working annular blowout preventer (7), a fixed slip group (9) and a moving slip group (10) from bottom to top;

the working annular blowout preventer (7) can seal tools of any shape and realize zero sealing in emergency;

the balance pressure relief system (8) is used for balancing or relieving the pressure in the working annular blowout preventer (7) and the working single ram blowout preventer;

the fixed slip group (9) is arranged on the working annular blowout preventer (7) and is matched with the floating slip group (10) to finish the operation of lifting and lowering an oil pipe;

the frame comprises a lower platform and an upright post; a lower substrate (13) is arranged on the lower platform;

the upper platform and the high-altitude operation platform comprise an upper platform (14) and a high-altitude driller platform;

the upper platform (14) comprises an upper base plate (12), a main pedal guardrail and a driller platform (15);

the driller's platform (15) is fixed at one side corner of the main pedal, the guardrail of the main pedal is arranged at the edge of the main pedal, and the upper base plate (12) extends out of the central through hole of the main pedal;

the upright posts are connected with the upper substrate (12) and the lower substrate (13);

the lifter system (37) comprises a lifting hydraulic cylinder (11) and a control valve group; the lifting hydraulic cylinder (11) is connected with the control valve group through a hydraulic pipeline;

the upper substrate (12) and the lower substrate (13) are respectively connected to the upper end and the lower end of the lifting hydraulic cylinder (11);

the high-altitude driller platform is fixed on an upper platform (14).

2. The apparatus for low pressure well operations in shallow layers according to claim 1, characterized in that said balanced decompression system (8) comprises: balance pressure relief four-way, manual plug valve, hydraulic plug valve and wellhead pressure gauge.

3. The equipment suitable for the operation of the shallow low-pressure oil well under pressure as claimed in claim 1, characterized in that the upper and lower terminal points of the lifting hydraulic cylinder (11) are designed with hydraulic buffer structures to make the lifting hydraulic cylinder (11) move stably; the control valve group uses a high-flow control valve.

4. The apparatus of claim 1, wherein the active rotary table is designed with a mechanical locking device.

5. The apparatus of claim 1, wherein the workover system comprises a derrick, a crown block, a traveling block, and a winch.

6. The apparatus for the operation of shallow low pressure oil wells under pressure according to claim 1, characterized in that the working annular blowout preventer (7) is provided with a buffer accumulator.

7. The equipment suitable for the operation under pressure of the shallow low-pressure oil well is characterized in that the power source system (21) for the operation under pressure comprises a hydraulic pump, a hydraulic circuit, an electric circuit system and an air circuit system.

8. The equipment suitable for the operation under pressure of the shallow low-pressure oil well is characterized in that the upper platform (14) further comprises an upper platform accessory, and the upper platform accessory comprises a lower tubing steel wire rope fixing rod (16), a falling protector fixing rod, an escape device fixing rod (17) and a hydraulic clamp tail rope fixing rod (18) which are vertically arranged on a main pedal.

9. The equipment suitable for the operation of the shallow low-pressure oil well under pressure is characterized in that the accessory equipment comprises a coupling detector (19), a telescopic protective ladder (20), a main machine transportation pry (22), a hoisting sling and a hydraulic pipeline;

the coupling detector (19) comprises a coupling detector shell (23) and a coupling detector component (24); the coupling detector part (24) is installed inside coupling detector casing (23), coupling detector (19) are installed between safe semi-closed ram preventer (4) and lower work semi-closed ram preventer (6), flexible protection cat ladder (20) are hung in last platform (14) department, host computer transportation sled (22) are used for the fixed pressure operation machine of laying of level, the hoist and mount hoist is installed in pressure operation machine hoisting point department, hydraulic line is used for connecting pressure operation power source system (21) and pressure between the operation machine, play the effect of transmission fluid pressure power.

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