CN110374545A - A kind of movement well dynamic piston component capable of reversing - Google Patents

Abstract

A downhole power piston assembly with reversible action, including piston cylinder, piston rod, control cylinder, limit sleeve, pressure relief needle valve and other parts. The two cavities at both ends are connected. There are sealing rings at both ends of the control cylinder and an air cavity in the middle. The control cylinder is set outside the piston cylinder. The pressure in the component is released on the ground, and the reciprocating movement of the piston can be realized by driving the control cylinder to move back and forth through operations such as steel wire tension and gravity impact. The piston thrust depends on the downhole pressure and the area of the piston. Compared with the reciprocating mechanism composed of the motor lead screw in the transmission downhole tool, the present invention has greater thrust, reliable and rapid action, and can completely omit the electrical components in some application environments, which has the advantages of reducing costs and the risk of well jamming advantage.

Description

A reversible action downhole power piston assembly

technical field

The invention belongs to the field of oil and gas field development, in particular to a reversible downhole power piston assembly.

Background technique

Downhole sealing tools are commonly used instruments and equipment in oil and gas well testing, such as layered pressure measuring instruments, seal inspection instruments, profile control plugging tools, downhole switch tools, etc. In the traditional structure, a motor lead screw is generally used to form a reciprocating mechanism or a one-way hydraulic piston is used to compress a leather cup or a rubber tube to achieve sealing. When the motor screw mechanism is used, the thrust is limited, and the hollow self-sealing cup can only be used for sealing, which cannot bear the two-way pressure difference and maintain the sealing effect for a long time, and the sealing pressure difference is also small; when using the one-way hydraulic piston, although it can be achieved Larger thrust and solid rubber cartridge are used, but the piston will fail once it moves. It is obviously not applicable to the situation that needs to go down the well once and seal repeatedly, such as seal inspection construction.

Contents of the invention

In order to solve the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a downhole power piston assembly with reversible action, which can solve the problem of multiple compressions of the solid rubber barrel downhole, and can perform reciprocating movements multiple times to meet the requirements of multiple downhole tools. The need for secondary sealing and unsealing.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A downhole power piston assembly with reversible action, including a piston barrel 8, a piston rod 9 is installed inside the piston barrel 8, a piston rod sealing ring 7 is set on the large end of the piston rod 9, and a limit sleeve is set on the small end of the piston rod 9 cylinder 10, a piston cylinder sealing ring 11 is installed between the piston cylinder 8 and the small end of the piston rod 9, a plug 3 is installed on the other side of the piston cylinder 8, and a plug is arranged between the plug 3 and the piston cylinder 8 The head sealing ring 4 forms two independent cavities on both sides of the piston rod sealing ring 7, and the first pressure guiding hole 12 and the second pressure guiding hole 13 are symmetrically opened on both sides of the lower end of the piston barrel 8, and the first guiding hole 12 The pressure hole 12 and the second pressure guide hole 13 communicate with the above-mentioned two independent cavities respectively, the outer side of the piston cylinder 8 is covered with a control cylinder 6, and the two ends of the control cylinder 6 are symmetrically equipped with four control cylinder sealing rings 5, Two control cylinder sealing rings 5 form a group to seal the first pressure guiding hole 12 and the second pressure guiding hole 13, and the plug 3 is provided with a pressure relief hole 14 communicating with the first pressure guiding hole 12, and the plugging The upper end of the head 3 is equipped with a pressure relief needle valve 2 communicating with the pressure relief hole 14, and a needle valve sealing ring 1 is installed on the pressure relief needle valve 2.

The plug 3 and the plug sealing ring 4 are screwed on the piston cylinder 8.

The piston rod 9 controls the reciprocating stroke of the piston through the length of the limit sleeve 10. The longer the limit sleeve 10, the shorter the movement space left for the piston rod 9, and the shorter the limit sleeve 10, the shorter the space for the piston rod. 9 has a longer movement space.

Based on the above technical scheme, the present invention has the following technical characteristics:

Because the action of the piston rod 9 is completed in an instant, the action is fast and reliable; because the control cylinder 6 can be moved back and forth through gravity impact, lifting and other actions, the trigger is reliable, and no electrical components are required to avoid the well being stuck and falling due to circuit failure. Wait for an accident.

Description of drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a state diagram of the present invention when going into a well.

Fig. 3 is a state diagram when the piston rod 9 moves to the left.

State diagram when piston rod 9 moves to the right during the time of Fig. 4.

In the figure: needle valve sealing ring 1; pressure relief needle valve 2; plug 3; plug sealing ring 4; control cylinder sealing ring 5; control cylinder 6; piston rod sealing ring 7; piston cylinder 8; piston rod 9; Bit sleeve 10; piston barrel sealing ring 11; first pressure guide hole 12; second pressure guide hole 13; pressure relief hole 14.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Referring to Figures 1 to 4, a reversible downhole power piston assembly includes a piston barrel 8, a piston rod 9 is installed inside the piston barrel 8, a piston rod sealing ring 7 is set on the big end of the piston rod 9, and the piston rod 9 A limit sleeve 10 is set on the small end, a piston cylinder sealing ring 11 is installed between the piston cylinder 8 and the small end of the piston rod 9, and a plug 3 is installed on the other side of the piston cylinder 8, and the plug 3 and the piston A plug sealing ring 4 is disposed between the barrels 8, and two independent cavities are formed on both sides of the piston rod sealing ring 7, and the first pressure guiding hole 12 and the second guiding hole 12 are symmetrically opened on both sides of the lower end of the piston barrel 8. The pressure hole 13, the first pressure guide hole 12 and the second pressure guide hole 13 communicate with the above two independent cavities respectively, the outer side of the piston cylinder 8 is covered with a control cylinder 6, and the two ends of the control cylinder 6 are symmetrically equipped with 4 A control cylinder seal ring 5, two control cylinder seal rings 5 are a group to seal the first pressure guide hole 12 and the second pressure guide hole 13, the plug 3 is provided with the first pressure guide hole 12 communicated The pressure relief hole 14, the upper end of the plug 3 is equipped with a pressure relief needle valve 2 communicating with the pressure relief hole 14, and a needle valve sealing ring 1 is installed on the pressure relief needle valve 2.

The plug 3 and the plug sealing ring 4 are screwed on the piston cylinder 8.

The piston rod 9 controls the reciprocating stroke of the piston through the length of the limit sleeve 10. The longer the limit sleeve 10, the shorter the movement space left for the piston rod 9, and the shorter the limit sleeve 10, the shorter the space for the piston rod. 9 has a longer movement space.

Referring to Fig. 1, when the control cylinder 6 moves to the right, the cavity on the left side of the piston rod 9 communicates with the external environment through the first pressure guide hole 12, and the piston rod 9 moves to the right under the action of the pressure difference, and the moving stroke is determined by The limit sleeve 10 controls; when the control cylinder 6 moves to the left, the cavity on the left side of the piston rod 9 communicates with the air cavity through the first pressure guide hole 12, and the internal pressure is released, while the cavity on the right side of the piston rod 9 passes through The second pressure guide hole 13 is in communication with the external environment pressure, and the piston rod 9 bears the leftward pressure difference force, and then moves leftward, and the moving distance is the same as when moving rightward. When the control cylinder 6 moves left and right again, the cavities on both sides of the piston rod 9 are alternately communicated with the external environment pressure and the air cavity, so that the piston rod 9 also reciprocates. The thrust of the piston rod 9 depends on the downhole pressure and the area of the piston, and the number of reciprocating movements is equal to the ratio of the volume of the air cavity to the displacement of the piston. +

Fig. 2 to Fig. 4 are a kind of specific embodiment of the present invention, wherein as shown in Fig. 2, the outer diameter of piston assembly is φ42mm; The diameter is φ38mm, the minor diameter is φ30.4mm, the length is 104mm; the piston stroke is 14mm. After calculation, it can be seen that the effective area of the piston is 349mm ² , the displacement of the piston is 4886mm ³ , the volume of the air chamber is 42461mm ³ , the number of reciprocating movements of the piston is rounded to 8 times, the downhole pressure is 30Mpa, and the thrust of the piston is 10469N, about It is 1068Kg.

When the instrument goes downhole, the positions of the parts of the piston assembly are shown in Figure 2. At this time, the cavities on both sides of the piston rod 9 are filled with air, and the small end on the right side of the piston rod 9 is exposed to the pressure of the external environment, and the piston rod 9 is pushed to the left. , keep at the position shown in Figure 2. Both the first pressure guiding hole 12 and the second pressure guiding hole 13 are sealed, and the air cavity is not connected with any cavity.

After the instrument is in place, rely on the impact of gravity to move the control cylinder 6 to the right, as shown in Figure 3. At this time, the right side of the piston rod 9 communicates with the air cavity through the second pressure guiding hole 13 , and the left side communicates with the external environment pressure through the first pressure guiding hole 12 . The left side of the piston rod 9 is stressed, and moves 14mm to the right, and the compressible rubber tube completes the sealing.

After the test is completed, the control cylinder 6 is moved to the left by pulling the steel wire, as shown in FIG. 4 . Now the right side of the piston rod 9 is in communication with the external environment pressure through the second pressure guiding hole 13, and the left side is in communication with the air cavity through the first pressure guiding hole 12, and the original pressure in the left cavity is balanced by the air cavity, and the piston rod 9 Forced on the right side, move 14mm to the left, and at the same time, discharge the liquid in the left cavity into the air cavity, and complete the unsealing of the rubber cartridge.

When it needs to be sealed again, rely on the impact of gravity to make the control cylinder 6 move to the right again, trigger the piston rod 9 to push right to complete the sealing; after the test is completed, rely on the steel wire to pull the control cylinder 6 to move left, trigger the piston rod 9 to push left Complete unsealing; until a total of 8 reciprocating strokes, the air cavity is filled with liquid.

After the instrument is lifted out of the ground, the pressure relief needle valve 2 is opened, the pressure in the left end of the piston rod 9 and the air cavity is released through the pressure relief hole 14 and the liquid is discharged, and then the pressure relief needle valve 2 is closed, and the instrument can be used in the well again.

Claims (3)

1. a kind of movement well dynamic piston component capable of reversing, it is characterised in that: including piston cylinder (8), pacify inside piston cylinder (8) It fills piston rod (9), piston set bar sealing ring (7) in the big end of piston rod (9), is set with limit on the small end of piston rod (9) Sleeve (10) is equipped with piston cylinder sealing ring (11) between the piston cylinder (8) and the small end of piston rod (9), piston cylinder (8) The other side is equipped with plug (3), plug sealing ring (4) is configured between plug (3) and piston cylinder (8), in piston rod seals (7) Two sides are respectively formed two individual cavities, and the piston cylinder (8) lower end two sides are symmetrically provided with the first pressure guide hole (12) and second Pressure guide hole (13), the first pressure guide hole (12) and the second pressure guide hole (13) are connected to above-mentioned two individual cavity respectively, the work It is cased with application cylinder (6) on the outside of plug tube (8), the both ends of application cylinder (6) are symmetrically equipped with (4) a application cylinder sealing ring (5), two controls Cylinder sealing ring (5) is one group and seals the first pressure guide hole (12) and the second pressure guide hole (13), and the plug (3) is equipped with the The relief hole (14) that one pressure guide hole (12) communicates, the upper end of plug (3) are equipped with the pressure release needle-valve communicated with relief hole (14) (2), needle-valve sealing ring (1) is installed on pressure release needle-valve (2).

2. one kind movement well dynamic piston component capable of reversing according to claim 1, it is characterised in that: the plug (3) and plug sealing ring (4) is by being screwed at piston cylinder (8).

3. one kind movement well dynamic piston component capable of reversing according to claim 1, it is characterised in that: the piston Bar (9) controls piston reciprocating stroke by the length of spacing collar (10), and the spacing collar (10) the long, leaves piston rod (9) for Space is shorter, and the spacing collar (10) the short, and the space for leaving piston rod (9) for is longer.