RU2364701C1 - Method of preventer crimping on well - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil-producing industry, particularly to method of sealing of well mouth. It includes mounting of preventer with casing head, allowing nozzle, on casing pipe, location nearby packer mouth with mechanical drive, taken out on original ground through the supporting pipe, insulation of bottom part of well against preventer by erection of packer, well filling higher than packer by process liquid, sealing through the preventer of supporting pipe, creation inside the preventer through the branch of casing head of testing pressure, implementation of technological isolation, pressure change valuation, conclusion about tightness or leakage of preventer, pressure release in preventer, depressurisation of preventer, packer releasing, discharge of process liquid from the space above packer into well and removing of packer with drive and supporting pipe from well.

EFFECT: providing of simplicity and reliability during operation, and also provides definition of preventer tightness on well.

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Description

The invention relates to the oil industry and is intended to seal the wellhead.

Known preventer, which contains a housing with an axial channel for the passage of pipes with technological equipment into the well, pipe dies with a piston hydraulic actuator mounted on the side covers, and blind dies with a piston hydraulic actuator mounted on the side covers, hydraulic cylinders connected in pairs by communication channels for supplying a working liquids. According to the invention, each communication channel of the hydraulic cylinder with the discharge line of the working fluid is equipped with a shut-off valve. Part of the shut-off valve is located in the housing, and part in the side cover. When the housing with the side cover is closed, the bypass valve is in the “open” position, and when the side cover is removed to replace the dies, the bypass valve can block the hydraulic cylinder communication channel with the working fluid injection line to ensure the hydraulic drive system is tight, in which the working fluid from the hydraulic cylinder cavity it does not follow (RF Patent No. 2264528, published. 2005.11.20).

The preventer ensures the preservation of the tightness of the connection of the channels with the cavity of the hydraulic cylinder at the time of dismantling the side cover. The preventer does not allow to compress it in the well.

Closest to the proposed invention is a preventer, which contains a housing with a Central axial channel and upper and lower sealing elements between which there is a lock chamber. Each sealing element is respectively equipped with upper and lower hydraulic actuators for sealing the pipe string being lowered or raised into the well. The preventer is connected to a pump station equipped with upper and lower pressure regulators. The lock chamber is made with the possibility of tight separation into the upper and lower cavities. The upper sealing element is made to rotate without violating the tightness of the lock chamber. The upper cavity of the lock chamber is made with the possibility of communication with the upper hydraulic drive. The lower cavity of the lock chamber is configured to communicate with the pumping station through the lower pressure regulator after pressing the lower sealing element to the pipe string under the action of the lower hydraulic drive. The inner space of the pipe string is made with the possibility of communication with the pumping station through the upper pressure regulator (RF Patent No. 2304693, published. 2007.08.20).

It provides simplicity and reliability of operation, however, pressure testing and testing of the preventer are absent.

The proposed invention solves the problem of crimping the preventer in the well.

The problem is solved in that in the method of crimping the preventer in the well, a preventer with a casing head having a nozzle is mounted on the casing, a packer with a mechanical drive brought to the surface through the support pipe is placed near the mouth, the bottom of the well is isolated from the preventer by setting the packer, the well is higher the packer and the preventer are filled with a process fluid having a liquid consistency at the pressure test temperature, the support pipe is sealed through the preventer, inside the preventer through the pipe branch pipe g dexterous pressurized test exposure process is performed, to evaluate changes in pressure, inferring leaks or leakage of BOP, relieve the pressure in the BOP, BOP depressurized, raspakerovyvayut packer fluid is drained into the wellbore above the packer, the packer is removed from the drive and support tube from the well.

SUMMARY OF THE INVENTION

After mounting on the well, the preventer must be pressurized to the maximum working pressure in the production casing. However, at present, there are no reliable methods of crimping the preventer after its installation in the well. The proposed method solves the problem of crimping the preventer after its installation in the well. The problem is solved as follows.

A preventer with a column head having a nozzle is mounted on the casing string. In the well near the mouth, a packer is placed with a mechanical drive brought to the surface through the support pipe. To do this, a packer with a drive is lowered through the preventer into the well with a speed of not more than 1 m / s. Isolate the bottom of the well from the preventer by setting the packer. The well above the packer and the preventer are filled with water. The support pipe is sealed through a preventer. Inside the preventer, test pressure is generated through the nozzle of the column head. The rate of pressure rise is 0.3-0.5 MPa / s. Carry out technological exposure for 30 minutes. Assess the change in pressure. A preventer is considered leakproof if the pressure drop does not exceed 5%. Make a conclusion about the tightness or leakage of the preventer. Relieve pressure in the preventer. The pressure test is released at a speed of not more than 1 MPa / s. Seal the preventer. Unpack the packer. Drain water over the packer into the well. Remove the packer with the drive and the support pipe from the well at a speed of not more than 1 m / s.

Concrete example

They perform pressure testing of the preventer in an oil well. The well has a casing with a diameter of 146 mm. A device for crimping the preventer according to FIG. 1 is mounted on the well.

Figure 1 shows a device for crimping a preventer in a well, conventionally consisting of a device for packing and a device for crimping.

The packing device consists of a support pipe 1 having a through groove 2. A support plate 3, rubber cuffs 4 and 5, a washer 6, a clamping plate 7 and a pusher 8 are put on the support pipe 1 (see section AA in FIG. 2) passing through the groove 2 and centered in the clamping plate 7. The support pipe 1 is plugged with a plug 9, which also serves as a support for the support plate 3. On top of the plunger 8 in the support pipe 1 is a rod 10, which serves as a channel for transmitting force from the bolt 11 to the pusher 8. Nut 12 is connected to the support pipe 1 by a sleeve 13.

For crimping, use a packing device 14, a column head 15, a preventer 16 with a transition coil 17, a column pipe 18 connected on one side to the column head 15 by a coupling 19, and on the other hand with a casing of the well 20 by a coupling 21, an elevator 22 serving as a support for the packing device 14. The nozzles 23 of the column head 15 are connected to the discharge line of the pump unit (not shown in FIG.). The preventer 16 is equipped with dies 24 for compression of the support pipe 1.

The device operates as follows.

The packing device 14, engaged with the elevator 22, is lowered at a speed of 0.9 m / s through the preventer 16, the adapter coil 17, the column head 15 and the column pipe 18 into the casing 20 so that the rubber cuffs 4 and 5 are below the connection of the casing 20 with a column pipe 18, and the elevator 22 rested on the upper plane of the preventer 16. Then tighten the bolt 11 with a torque of 200 N · m clockwise. The resulting axial force through the rod 10, the pusher 8 and the clamping plate 7 presses the rubber cuffs 4 and 5 to the support plate 3. The cuffs 4 and 5, in turn, elastically deforming, are pressed against the wall of the casing 20, isolating the lower part of the wellbore. The cut off cavity above the cuffs 4 and 5 through the discharge line and nozzles 23 is filled with process fluid, which is a fluid at the temperature of pressure testing, in this case, with fresh water. The rams 24 of the preventer 16 clamp the support tube 1, thereby eliminating the air cushion inside the preventer 16 during filling with liquid. Between the dies 24 and the rubber cuffs 4 and 5, a closed chamber is created inside the column pipe 18, the column head 15, and the preventer 16. A pressure of 10 MPa is created inside the preventer 16 through the discharge line of the pump unit CA-320. The rate of pressure rise is 0.4 MPa / s. After technological exposure for 30 minutes, it is determined that the pressure drop was 1% of the pressure test. Make a conclusion about the tightness of the preventer. The pressure test is released at a speed of 0.9 MPa / s along the discharge line. Unload the dies 24 and depressurize the preventer.

Unpack the packing device by turning the bolt 11 counterclockwise. The process fluid is drained into the wellbore, a packer is removed from the well at a speed of 0.9 m / s.

As a result, it is possible to determine the tightness of the preventer in the well.

Claims (1)

A method of crimping a preventer in a well, including mounting a preventer with a casing head having a nozzle on a casing, placing it near the mouth of the packer with a mechanical drive brought to the surface through the support pipe, isolating the bottom of the well from the preventer by setting the packer, filling the well above the process packer liquid, sealing through the preventer of the support pipe, creating test pressure inside the preventer, carrying out technological exposure, evaluating the pressure change, conclusion about of preventer leakage or leakage, pressure relief in the preventer, depressurization of the preventer, unpacking and removal of the packer with the drive and the support pipe from the well, characterized in that the packer with the drive on the support pipe is lowered at a speed of not more than 1 m / s, create inside the wellhead fittings test pressure with a rate of pressure rise of 0.3-0.5 MPa / s, technological exposure is carried out for at least 30 minutes, pressure in the wellhead valve is released at a speed of not more than 1 MPa / s, and after unpacking the packer, the process fluid is drained nce the wellbore above the packer and the packer is removed from the drive and support tube from the well at a speed of 1 m / s.

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