Self-liquid-filling ball injection pressure conversion device for perforation, perforation device and perforation process

Abstract

The invention relates to a pressure conversion device, in particular to a self-liquid-filling ball injection pressure conversion device for perforation, a perforation device and a perforation process, and aims to ensure communication between a pipe column and an annulus in a well before perforation on the premise of not increasing construction procedures. In order to solve the problems of how to realize circulating well killing to stop blowout and how to prevent perforation liquid from being scattered to the ground of a well mouth to cause pollution during recovery if problems occur in the well before perforation, the self-liquid-filling ball-throwing pressure conversion device for perforation establishes a passage for communicating the inside and the outside of a shell through a conical hole and a communicating hole; when the well is tripped into the well, the passage ensures the communication with the annulus in the well, and if problems occur in the well, circulating well killing can be realized through the passage; and during pressure detonation, the annulus in the well can be isolated through matching of the plugging ball and the conical hole, pressure is transmitted to the pressure tapping exploder through the pressure transmitting hole to complete detonation, and the through hole in the pressure tapping exploder is communicated with the annulus in the well after detonation.

Description

Technical Field

[0001] The invention relates to a pressure conversion device, in particular to a self-filling liquid ball-throwing pressure conversion device for perforating, a perforating device and a perforating process. Background Art

[0002] The pressure detonator used in the oil and gas production process is suitable for pressurized detonation in various well conditions, including vertical wells, heavy oil wells, highly inclined wells, horizontal wells, etc. By applying pressure at the wellhead to act on the piston of the pressure detonator, the piston shears the shear pin or breaks through the pressure limit under the combined action of the wellhead pressure and the wellbore fluid pressure, and then moves rapidly to trigger the detonator, produce a detonation, and then detonate the perforating gun string connected to the pressure detonator.

[0003] The existing pressure detonation device is closed during the process of going down the well, and its interior is not connected to the annulus in the well. When a blowout occurs, it is impossible to achieve circulation well pressure to stop the blowout, which poses certain safety hazards. During the process of going down the well, it is necessary to manually inject perforating fluid into the pipe string, which is time-consuming and laborious. Secondly, when the pipe string is pulled out of the well, the perforating fluid in the pipe string will emerge from the pipe string and spill onto the wellhead surface, causing pollution. In order to solve the above problems, the prior art provides a pressure-opening detonating device, a through hole is provided on its shell, and when the device is pressure-opening and detonating, the through hole is blocked by its own piston to ensure that the pressure will not leak into the annulus in the well; after the pressure-opening and detonating is completed, the piston cuts off the shear pin and moves downward, and the through hole on the shell connects the inside and outside of the pipe string, ensuring that during the operation of pulling out the pipe string, the perforating fluid flows from the pipe string into the wellbore through the through hole of the shell and will not bubble up to the wellhead surface. However, when the device is not pressure-opening and detonating, it is still not connected with the annulus in the well, and it is still necessary to add a process of injecting perforating fluid into the pipe string when lowering it. Moreover, before perforating, if a blowout occurs, it cannot achieve circulating well pressure because it is not connected with the annulus in the well. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems of how to ensure the connection between the pipe string and the annulus in the well before perforating without increasing the construction process; and how to achieve circulating well pressure to stop the blowout if there is a problem in the well before perforating, and how to prevent the perforating fluid from spilling to the wellhead surface and causing pollution during recovery, and to provide a self-filling liquid ball pressure conversion device for perforating, a perforating device and a perforating process.

[0005] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0006] A self-filling liquid ball-throwing pressure conversion device for perforating, which is special in that it comprises a shell and a blocking ball;

[0007] The top end of the shell is used to connect with the oil pipe, and the bottom end is used to connect with the pressure opening initiator;

[0008] A blocking seat is provided inside the shell, a conical hole is provided at the center of the top of the blocking seat, and the large hole of the conical hole faces the top of the shell; a connecting hole is provided on the outer wall of the shell, and the conical hole is connected with the outside of the shell through the connecting hole;

[0009] A pressure transmission hole is axially provided on the blocking seat to connect the upper and lower ends of the shell;

[0010] The blocking ball is used to cooperate with the tapered hole to block the tapered hole.

[0011] Furthermore, the shell includes a large diameter section arranged near the top end and a small diameter section arranged near the bottom end; the small diameter section is provided with an external thread, which is used for threaded connection with the pressure opening initiator;

[0012] The plugging seat is arranged inside the large diameter section and located at the bottom of the large diameter section. An internal thread is arranged on the inner wall of the large diameter section above the plugging seat, which is used for threaded connection with the oil pipe.

[0013] Furthermore, a blind hole is axially opened at the bottom of the tapered hole, and the communicating hole is radially opened along the outer wall of the shell and communicates with the blind hole;

[0014] There are a plurality of pressure transmission holes which are arranged around the blind hole, and the top openings of the pressure transmission holes are located on the conical surface of the conical hole.

[0015] Meanwhile, the present invention also provides a perforating device, including a relatively deep short joint, a tubing, a perforating gun and a pressure perforating detonator, which is special in that: it also includes the above-mentioned self-filling liquid ball pressure conversion device for perforating;

[0016] The deeper short joint, the oil pipe, the self-filling liquid ball pressure conversion device for perforating, the pressure perforating detonator and the perforating gun are connected in sequence from top to bottom;

[0017] The pressure opening initiator comprises a housing, a piston, a firing pin, a shearing assembly and an initiator;

[0018] The housing comprises a first joint and a second joint which are axially connected, the right end of the first joint is sealed and arranged inside the left end of the second joint, the detonator is coaxially arranged inside the second joint; the left end of the piston is sealed and arranged inside the first joint;

[0019] The shearing assembly is arranged between the outside of the piston and the inside of the second joint, and is used to fix the position of the piston. The shearing assembly can be broken by force;

[0020] The firing pin is detachably mounted on the end of the piston close to the detonator; a through hole is radially opened on the outer wall of the first joint corresponding to the position of the piston;

[0021] The position setting of the through hole satisfies that when the shear assembly is broken by force, the piston moves toward the detonator until the firing pin hits the detonator, and the through hole connects the interior of the first joint with the annulus in the well.

[0022] Further, the shear assembly includes a shear sleeve and a plurality of shear pins;

[0023] The second joint is provided with a step surface inside, the large diameter section of the step surface faces the first joint, the inner end surface of the first joint, the outer wall of the piston and the inner wall of the large diameter section of the step surface constitute a mounting cavity, the shear sleeve is arranged on the outer wall of the piston and is located in the mounting cavity, and the piston and the shear sleeve are connected by a plurality of shear pins;

[0024] The outer diameter of the piston is smaller than or equal to the inner diameter of the small diameter section corresponding to the step surface of the second joint.

[0025] At the same time, the present invention also provides a perforation process, based on the above-mentioned perforation device, which is special in that it includes the following steps:

[0026] S1 lowers the perforating device into the well;

[0027] S2 When the deeper short section detects that it has reached the designated formation, the plugging ball is dropped from the wellhead, and the plugging ball falls into the conical hole of the self-filling liquid ball-dropping pressure conversion device for perforating;

[0028] S3 performs pressure pumping from the wellhead, and the pressure is transmitted from the pressure transmission hole to the piston of the pressure opening initiator, and the piston transmits the pressure to the shear assembly;

[0029] The S4 shear assembly breaks under stress, and then the piston drives the striker to hit the detonator, activating the perforating gun to complete the perforation of the designated formation;

[0030] S5 Retrieve the perforating device from the wellhead.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The present invention provides a self-filling liquid ball pressure conversion device for perforating, which establishes a passage connecting the inside and outside of the shell through a tapered hole and a connecting hole. When lowered into the well, the passage ensures the connection with the annulus in the well. When a problem occurs, the passage can be used to achieve circulating well pressure to stop the blowout. During pressure detonation, the annulus in the well can be isolated through the cooperation of the sealing ball and the tapered hole, and the pressure is transmitted to the pressure hole detonator through the pressure transmission hole to complete the detonation. After detonation, the through hole on the pressure hole detonator connects the inside and outside of the pipe column to prevent the perforating fluid from bubbling to the wellhead surface when it is pulled out. There is no need to manually fill the pipe column with liquid. The entire device can achieve self-filling, saving construction steps. The device has a simple structure and is easy to process.

[0033] (2) A perforating device provided by the present invention comprises a relatively deep short section, a tubing, a self-filling liquid ball pressure conversion device for perforating, a pressure perforating detonator and a perforating gun connected in sequence from top to bottom. When lowered into a well, a passage formed by the tapered hole, the blind hole and the connecting hole of the self-filling liquid ball pressure conversion device for perforating connects the inside and outside of the entire device, realizes self-filling liquid, and ensures the connection with the annulus in the well. If a blowout occurs in the well, the blowout can be stopped by circulating well pressure through the passage. During pressure detonation, the annulus in the well is isolated by the cooperation of the sealing ball and the tapered hole, and the pressure is transmitted to the piston of the pressure perforating detonator through the pressure transmission hole. The piston of the pressure perforating detonator transmits the pressure to the shearing assembly. The shearing assembly is broken by force, and the piston moves downward so that the firing pin hits the detonator to complete the detonation of the perforating gun. When being pulled out, the through hole connecting the device of the pressure perforating detonator is connected to the annulus in the well, ensuring that the perforating fluid will not bubble up to the wellhead surface during the pulling out. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A cross-sectional view of an embodiment of a self-filling liquid ball pressure conversion device for perforating according to the present invention;

[0035] Figure 2 A schematic structural diagram of a perforating device embodiment of the present invention;

[0036] Figure 3 It is a schematic structural diagram of a pressure perforating initiator in an embodiment of a perforating device of the present invention.

[0037] The following are the descriptions of the reference numerals:

[0038] 01-self-filling liquid ball pressure conversion device for perforating, 1-shell, 1001-large diameter section, 1002-small diameter section; 2-sealing seat, 3-blind hole, 4-connecting hole, 5-pressure transmission hole, 6-sealing ball, 7-deeper short section, 8-oil pipe, 9-pressure opening detonator, 91-first joint, 911-through hole; 92-piston, 93-second joint, 94-striker, 95-detonator, 96-shear sleeve, 961-shear pin; 10-perforating gun. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and exemplary embodiments.

[0040] Reference Figure 1The present invention provides a self-filling liquid ball pressure conversion device for perforating, comprising a housing 1 and a plugging ball 6. The housing 1 comprises a large diameter section 1001 arranged near the top and a small diameter section 1002 arranged near the bottom. The small diameter section 1002 is provided with an external thread, which is used to be threadedly connected with a pressure hole opening initiator 9. A plugging seat 2 is arranged inside the large diameter section 1001, and the plugging seat 2 is located at the bottom of the large diameter section 1001. An internal thread for threading with an oil pipe 8 is arranged on the inner wall of the large diameter section 1001 above the plugging seat 2.

[0041] A conical hole for cooperating with a sealing ball 6 is provided at the top center of the sealing seat 2. The sealing ball 6 is used to cooperate with the conical hole to seal the conical hole. The large hole of the conical hole faces the top of the shell 1. A blind hole 3 is axially provided at the bottom of the conical hole, and a connecting hole 4 connected to the blind hole 3 is radially provided on the outer wall of the shell 1. The conical hole is connected to the outside of the shell 1 through the connecting hole 4. A pressure transmission hole 5 for connecting the upper and lower ends of the shell 1 is axially provided on the sealing seat 2. In order to ensure the pressure transmission effect, a plurality of pressure transmission holes 5 are provided and are all arranged around the blind hole 3, and the top opening of the pressure transmission hole 5 is located on the conical surface of the conical hole.

[0042] like Figure 2 As shown, the perforating device includes a deeper short section 7, a tubing 8, a self-filling liquid ball pressure conversion device 01 for perforating, a pressure perforating detonator 9 and a perforating gun 10, which are connected in sequence from top to bottom, wherein the deeper short section 7 is a professional device for detecting the underground depth position of the entire perforating device.

[0043] The structure of the pressure opening initiator 9 is as follows: Figure 3 As shown, it includes a housing, a piston 92 , a firing pin 94 , a shear assembly and an initiator 95 .

[0044] The outer shell includes a first joint 91 and a second joint 93 that are axially connected. The right end of the first joint 91 is arranged inside the left end of the second joint 93 through a threaded seal. The detonator 95 is coaxially arranged inside the second joint 93. The left end of the piston 92 is sealed in the first joint 91. The firing pin 94 is detachably installed at one end of the piston 92 close to the detonator 95. The shear assembly is used to fix the position of the piston 92, and it is arranged between the outside of the piston 92 and the inside of the second joint 93.

[0045] The shearing assembly includes a shearing sleeve 96 and a plurality of shearing pins 961. In order to install the shearing assembly, a step surface is provided inside the second joint 93, and the large diameter section of the step surface faces the first joint 91. The inner end surface of the first joint 91, the outer wall of the piston 92 and the inner wall of the large diameter section of the step surface constitute an installation cavity. The shearing sleeve 96 is sleeved on the outer wall of the piston 92 and is located in the installation cavity. The piston 92 and the shearing sleeve 96 are connected by a plurality of shearing pins 961. In order to ensure that the piston 92 can smoothly move toward the detonator 95 after the shearing pins 961 are cut off, the outer diameter of the piston 92 is less than or equal to the inner diameter of the small diameter section corresponding to the step surface of the second joint 93.

[0046] A through hole 911 is radially opened on the outer wall of the first joint 91 at a position corresponding to the piston 92. In order to ensure that the through hole 911 can connect the inside and outside of the device after pressure detonation, the position of the through hole 911 is set to meet the following requirements: when the shear assembly is broken under force, the piston 92 moves toward the detonator 95 until the firing pin 94 hits the detonator 95, and the through hole 911 connects the inside of the first joint 91 with the annulus in the well.

[0047] When the entire perforating device is lowered into the well, the conical hole, blind hole 3 and connecting hole 4 of the self-filling liquid ball pressure conversion device 01 for perforating are connected to the inside and outside of the device, ensuring the connection with the annulus in the well and realizing self-filling liquid. If a blowout occurs, this path can be used to realize circulating well killing; when the pressure is pressed and detonated, the conical hole is blocked by the blocking ball 6, the perforating device is isolated from the annulus in the well, and the pressure is transmitted from the pressure transmission hole 5 to the piston 92, and the piston 92 transmits the pressure to the shear pin 961. The shear pin 961 is sheared by force, and the piston 92 drives the striker 94 to hit the detonator 95 to activate the perforating gun 10. When it is pulled out, because the piston 92 no longer blocks the through hole 911, the through hole 911 connects the inside and outside of the perforating device, preventing the perforating fluid from escaping to the wellhead surface to cause pollution, and realizing green operation.

[0048] At the same time, the present invention also provides a perforating process, based on the above-mentioned perforating device, comprising the following steps:

[0049] S1 lowers the perforating device into the well;

[0050] S2 When the deeper short section 7 detects that it has reached the designated formation, the plugging ball 6 is dropped from the wellhead, and the plugging ball 6 falls into the tapered hole of the self-filling liquid ball-dropping pressure conversion device 01 for perforating;

[0051] S3: Pressure is applied from the wellhead, and the pressure is transmitted from the pressure transmission hole 5 to the piston 92 of the pressure opening initiator 9, and the piston 92 transmits the pressure to the shear assembly;

[0052] S4 The shear assembly is broken by the force, and then the piston 92 drives the striker 94 to hit the detonator 95, activating the perforating gun 10 to complete the perforation of the designated formation;

[0053] S5 Retrieve the perforating device from the wellhead.

[0054] The embodiments described above are merely descriptions of specific implementation methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A self-filling liquid ball pressure conversion device for perforating, characterized in that: It comprises a shell (1) and a blocking ball (6); The top end of the shell (1) is used to connect with the oil pipe (8), and the bottom end is used to connect with the pressure opening initiator (9); A blocking seat (2) is arranged inside the shell (1), a conical hole is provided at the center of the top of the blocking seat (2), and the large hole of the conical hole faces the top of the shell (1); a connecting hole (4) is provided on the outer wall of the shell (1), and the conical hole is connected to the outside of the shell (1) through the connecting hole (4); A pressure transmission hole (5) for connecting the upper and lower ends of the housing (1) is provided on the sealing seat (2) in an axially extending manner; The blocking ball (6) is used to cooperate with the tapered hole to block the tapered hole.

2. The perforating self-filling liquid ball-throwing pressure conversion device according to claim 1 is characterized in that: The shell (1) comprises a large diameter section (1001) arranged near the top end and a small diameter section (1002) arranged near the bottom end; the small diameter section (1002) is provided with an external thread for threaded connection with a pressure opening detonator (9); The sealing seat (2) is arranged inside the large diameter section (1001) and is located at the bottom of the large diameter section (1001). An internal thread is arranged on the inner wall of the large diameter section (1001) above the sealing seat (2) and is used for threaded connection with the oil pipe (8).

3. The perforating self-filling liquid ball-throwing pressure conversion device according to claim 2 is characterized in that: A blind hole (3) is axially provided at the bottom of the tapered hole, and the communicating hole (4) is radially provided along the outer wall of the shell (1) and is communicated with the blind hole (3); There are a plurality of pressure transmission holes (5) arranged around the blind hole (3), and the top openings of the pressure transmission holes (5) are located on the conical surface of the conical hole.

4. A perforating device, comprising a relatively deep short joint (7), a tubing (8), a perforating gun (10) and a pressure perforating detonator (9), characterized in that: It also comprises a self-filling liquid ball pressure conversion device (01) for perforating as claimed in any one of claims 1 to 3; The relatively deep short joint (7), the oil pipe (8), the self-filling liquid ball pressure conversion device for perforating (01), the pressure perforating detonator (9) and the perforating gun (10) are connected in sequence from top to bottom; The pressure opening detonator (9) comprises a housing, a piston (92), a striker (94), a shearing assembly and a detonator (95); The housing comprises a first joint (91) and a second joint (93) which are axially connected, the right end of the first joint (91) is sealed and arranged inside the left end of the second joint (93), and the detonator (95) is coaxially arranged inside the second joint (93); the left end of the piston (92) is sealed and arranged inside the first joint (91); The shearing assembly is arranged between the outside of the piston (92) and the inside of the second joint (93) and is used to fix the position of the piston (92). The shearing assembly can be broken when subjected to force. The firing pin (94) is detachably mounted on one end of the piston (92) close to the detonator (95); a through hole (911) is radially formed on the outer wall of the first joint (91) at a position corresponding to the piston (92); The position setting of the through hole (911) satisfies that: when the shear assembly is broken by force, the piston (92) moves toward the detonator (95) until the striker (94) hits the detonator (95), and the through hole (911) connects the interior of the first joint (91) with the annulus in the well.

5. The perforating device according to claim 4, characterized in that: The shear assembly comprises a shear sleeve (96) and a plurality of shear pins (961); The second joint (93) is provided with a step surface inside, the large diameter section of the step surface faces the first joint (91), the inner end surface of the first joint (91), the outer wall of the piston (92) and the inner wall of the large diameter section of the step surface form a mounting cavity, the shear sleeve (96) is sleeved on the outer wall of the piston (92) and is located in the mounting cavity, and the piston (92) and the shear sleeve (96) are connected by a plurality of shear pins (961); The outer diameter of the piston (92) is smaller than or equal to the inner diameter of the small-diameter section corresponding to the step surface of the second joint (93).

6. A perforating process, based on the perforating device according to claim 4, characterized in that: The following steps are involved: S1 lowers the perforating device into the well; S2 When the deeper short section (7) detects that it has reached the designated formation, the sealing ball (6) is dropped from the wellhead, and the sealing ball (6) falls into the conical hole of the self-filling liquid ball-dropping pressure conversion device (01) for perforating; S3: Pressure is applied from the wellhead, and the pressure is transmitted from the pressure transmission hole (5) to the piston (92) of the pressure opening initiator (9), and the piston (92) transmits the pressure to the shear assembly; S4 The shear assembly is broken by force, and then the piston (92) drives the striker (94) to hit the detonator (95), thereby activating the perforating gun (10) to complete the perforation of the designated formation; S5 Retrieve the perforating device from the wellhead.

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