Self-liquid-filling ball-throwing pressure conversion device for perforation, perforation pipe string and perforation process

Abstract

The invention relates to a pressure conversion device, in particular to a self-liquid-filling ball-throwing pressure conversion device for perforation, a perforation pipe string and a perforation process, and solves the technical problem that the purchase cost is high due to the fact that an existing pressure perforation detonating device is high in machining difficulty and high in machining precision requirement. According to the self-liquid-filling ball-throwing pressure conversion device for perforation, a channel for communicating the interior and the exterior of the shell is established through the conical hole and the communicating hole, when the device is put into a well, the channel guarantees communication with an annulus in the well, when the device is pressed and detonated, the annulus in the well can be isolated through cooperation of the plugging ball and the conical hole, and therefore the safety of the device is improved. Pressure is transmitted to the pressure electronic control unit or the pressure exploder through the pressure transmitting hole to complete detonation, the plugging ball is dissolved in the pulling-out process, a channel established by the conical hole and the communicating hole communicates the interior and the exterior of the shell again, and the whole device is simple in structure and convenient to machine.

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 pipe string and a perforating process. Background Art

[0002] The pressure detonator used in the process of oil and gas extraction 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 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] In the process of going down the well, the existing pressure detonating device cannot achieve circulating well pressure to stop the blowout because the entire tubing is closed and its interior is not connected to the annulus in the well. There are certain safety hazards. In the process of going down the well, it is necessary to manually inject perforating fluid into the tubing, which is time-consuming and laborious. Secondly, when the tubing is pulled out of the well, the perforating fluid in the tubing will emerge from the tubing and spill onto the wellhead surface, causing pollution. In order to solve the above problems, the prior art provides a pressure perforating detonating device, which has a through hole on its outer shell for connecting the inside and outside of the tubing. When the device is pressure-activated, the through hole is blocked by its own piston to ensure that the pressure will not leak into the annulus in the well; and after the pressure-activated detonation is completed, the piston cuts off the shear pin and moves down, and the through hole on the outer shell connects the inside and outside of the tubing. In the process of pulling out the tubing, the perforating fluid flows from the tubing into the wellbore through the through hole of the outer shell and will not emerge to the wellhead surface. However, compared with traditional pressure detonating devices, this type of pressure hole detonating device is more difficult to manufacture and requires higher machining precision, resulting in high procurement costs. How to carry out low-cost transformation of the pressure detonating device so that it can be connected with the annulus in the well during the process of going down the well, isolated from the annulus in the well during pressure detonation, and connected with the annulus in the well when being pulled out has become a major problem encountered by oilfield operating units. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that the existing pressure hole opening detonating device is difficult to process and has high processing accuracy requirements, resulting in high procurement costs. The design idea is to carry out low-cost transformation of the pressure detonating device so that it can be connected with the annulus in the well during the downhole process, isolated from the annulus in the well during pressure detonation, and connected with the annulus in the well when it is pulled out, thereby providing a self-filling liquid ball pressure conversion device for perforating, a perforating pipe string 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 housing is used to connect with the oil pipe, and the bottom end is used to connect with the pressure initiator or the pressure electronic control unit;

[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 sealing 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, and the blocking ball is made of a material that is soluble in chloride ions.

[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 detonator;

[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] Furthermore, the chloride ion-soluble material used to make the blocking ball is an aluminum-magnesium alloy material.

[0016] Meanwhile, the present invention also provides a perforating pipe string, including a relatively deep short joint, a tubing and a perforating gun, which is special in that it also includes the above-mentioned self-filling liquid ball pressure conversion device for perforating, a battery pack, an electronic time-delay detonation device, an electronic selective detonation device, a sealing tool, a bridge plug and a pressure electronic control unit;

[0017] The deeper short joint, oil pipe, self-filling liquid ball pressure conversion device for perforation, and pressure electronic control unit are connected in sequence from top to bottom;

[0018] The battery pack is connected to the tail end of the pressure electronic control unit, there are multiple perforating guns, and the electronic delayed detonation device is connected between adjacent perforating guns, the perforating gun at the top is connected to the tail end of the battery pack, the tail end of the perforating gun at the bottom is connected to the electronic selective detonation device, the top end of the sealing tool is connected to the tail end of the electronic selective detonation device, and the tail end is connected to the bridge plug;

[0019] The pressure electronic control unit is electrically connected to the battery pack, the battery pack is electrically connected to the electronic selective detonating device, and the electronic selective detonating device is electrically connected to the setting tool and each electronic delayed detonating device.

[0020] At the same time, the present invention provides a perforation process, based on the above-mentioned perforation pipe string, which is special in that it includes the following steps:

[0021] S1 lowers the perforating string into the well;

[0022] 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 pressure conversion device for perforating, and pressure is pumped from the wellhead, and the pressure is transmitted from the pressure transmission hole to the pressure electronic control unit;

[0023] When the S3 pressure electronic control unit reaches the starting pressure, the battery pack is activated, and the battery pack supplies power to the electronic selective detonator, which is then started;

[0024] The S4 electronic selective detonator activates the setting powder in the setting tool to start the setting tool, and the setting tool sets the bridge plug in the well. After the setting is completed, the bridge plug is separated from the setting tool;

[0025] The S5 electronic selective detonator activates multiple electronic delayed detonators separately;

[0026] The electronic time-delay detonator activated by S6 excites the perforating gun connected thereto after a delay of a predetermined time. During the delay period, the corresponding perforating gun is moved to a designated depth formation to complete perforation of the corresponding depth formation.

[0027] S7 repeats step S6 until all the corresponding depth formations are perforated;

[0028] S8: magnesium chloride or calcium chloride is injected from the wellhead, the plugging balls dissolve automatically, and then the perforating string is recovered from the wellhead.

[0029] At the same time, the present invention also provides a perforation process, based on the above-mentioned perforation pipe string, which is special in that it includes the following steps:

[0030] S1 lowers the perforating string into the well;

[0031] 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 pressure conversion device for perforating, and pressure is pumped from the wellhead, and the pressure is transmitted from the pressure transmission hole to the pressure electronic control unit;

[0032] The S3 pressure electronic control unit activates the battery pack after reaching the starting pressure. The battery pack continuously supplies power to the corresponding electronic selective detonating device within a preset period of time, and the electronic selective detonating device starts;

[0033] The S4 electronic selective detonator activates the setting powder in the setting tool to start the setting tool, and the setting tool sets the bridge plug in the well. After the setting is completed, the bridge plug is separated from the setting tool, and then the battery pack is in standby mode;

[0034] S5 moves the perforating pipe string until one of the perforating guns moves to the corresponding depth formation, and performs pressure pumping from the wellhead. After the pressure electronic control unit reaches the starting pressure, the battery pack is activated. The battery pack continuously supplies power to the electronic selective detonating device within a preset time period. The electronic selective detonating device activates the electronic time-delay detonating device connected to the perforating gun. After the delay reaches a preset time, the perforating gun is stimulated to complete the perforation of the corresponding depth formation, and then the battery pack is in a standby state again;

[0035] S6 repeats step S5 until all the corresponding depth formations are perforated;

[0036] S7: magnesium chloride or calcium chloride is injected from the wellhead, the plugging balls dissolve automatically, and then the perforating string is recovered from the wellhead.

[0037] Meanwhile, the present invention provides another perforating pipe string, including a relatively deep short joint, a tubing, a perforating gun and a pressure detonator, which is special in that: it also includes the above-mentioned self-filling liquid ball pressure conversion device for perforating;

[0038] The deeper short joint, the oil pipe, the self-filling liquid ball pressure conversion device for perforating, the pressure detonator and the perforating gun are connected in sequence from top to bottom;

[0039] The pressure detonator comprises a housing, a piston, a firing pin, a shear assembly and a detonator;

[0040] 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, and the detonator is coaxially arranged inside the second joint; the piston is sealed and arranged inside the first joint and the second joint;

[0041] The shearing assembly is arranged between the outside of the piston and the inside of the first joint and the second joint, and is used to fix the position of the piston. The shearing assembly can be broken by force;

[0042] The firing pin is detachably mounted on one end of the piston close to the detonator.

[0043] Further, the shear assembly includes a shear sleeve and a shear pin;

[0044] A first joint step surface is provided inside the first joint, a second joint step surface is provided inside the second joint, a large diameter section of the first joint step surface faces the second joint, a large diameter section of the second joint step surface faces the first joint, and the large diameter section of the first joint step surface and the large diameter section of the second joint step surface together form a mounting cavity;

[0045] The piston is located in the installation cavity, the shear sleeve is located between the inner wall of the installation cavity and the outer wall of the piston, and the piston and the shear sleeve are connected by a plurality of shear pins;

[0046] 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.

[0047] At the same time, the present invention provides another perforating process, which is based on the above-mentioned another perforating pipe string, and its special feature is that it includes the following steps:

[0048] S1 lowers the perforating string into the well;

[0049] 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;

[0050] S3 pressurizes the wellhead, and the pressure is transmitted from the pressure transmission hole to the piston, and the piston transmits the pressure to the shear assembly;

[0051] 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 formation at the specified depth;

[0052] After completing the perforation of the formation at this depth, S5 puts magnesium chloride or calcium chloride into the well, and the plugging balls dissolve by themselves, and then the perforating string is recovered from the wellhead.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] (1) The self-filling liquid ball pressure conversion device for perforating provided by the present invention establishes a passage connecting the inside and outside of the shell through the tapered hole and the connecting hole. When lowered into the well, the passage ensures the connection with the annulus in the well. When the pressure is pressed and detonated, the annulus in the well can be isolated through the cooperation of the sealing ball and the tapered hole. In this way, the perforating fluid will not bubble out during the process of lowering into the well and pulling out, thus realizing environmentally friendly and green operation. In addition, the entire device has a simple structure, is easy to process, and has a low cost.

[0055] (2) When the perforating pipe string provided by the present invention is lowered into the well, the conical hole, blind hole and connecting hole of the perforating self-filling ball pressure conversion device connect the inside and outside of the perforating pipe string, thereby ensuring the connection with the annulus in the well. During pressure detonation, the annulus in the well is isolated by the cooperation of the sealing ball and the conical hole, and the pressure is transmitted to the pressure detonator through the pressure transmission hole. The shear assembly of the pressure detonator is broken by the force, and the piston moves downward so that the firing pin hits the detonator to complete the detonation of the perforating gun. When pulling out, magnesium chloride or potassium chloride is added into the well, the sealing ball dissolves, and the passage is connected to the inside and outside of the shell again. No blowout or well gushing will occur during pulling out.

[0056] (3) When the perforating pipe string provided by the present invention is lowered into the well, the conical hole, blind hole and connecting hole of the perforating self-filling liquid ball pressure conversion device connect the inside and outside of the perforating pipe string, thereby ensuring the connection with the annulus in the well. During the pressure detonation, the annulus in the well is isolated by the cooperation of the sealing ball and the conical hole. Through the cooperation of multiple perforating guns and the electronic delay detonating device, the corresponding perforating gun can be moved to the formation of the corresponding depth within the delay time after the electronic delay detonating device is started. Because there are multiple electronic delay detonating devices and multiple perforating guns, formations of different depths can be perforated at different times, thus completing multi-stage perforating operations. Compared with the traditional operation mode of only performing one perforation in one trip to the well, the flexibility of the perforating operation is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a structural schematic diagram of an embodiment of a self-filling liquid ball-throwing pressure conversion device for perforating of the present invention;

[0058] Figure 2 This is a schematic structural diagram of a first embodiment of a perforating pipe string of the present invention;

[0059] Figure 3 This is a schematic structural diagram of a second embodiment of a perforating pipe string of the present invention;

[0060] Figure 4 It is a schematic diagram of the structure of the pressure detonator in the second embodiment of the perforating pipe string of the present invention.

[0061] The following are the descriptions of the reference numerals:

[0062] 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-conical hole, 8-deeper short section, 9-oil pipe, 10-pressure detonator, 101-first joint, 102-piston, 103-second joint, 104-striker, 105-detonator, 106-shear sleeve, 1061-shear pin; 11-perforating gun, 12-battery pack, 13-electronic delayed detonator, 14-electronic selective detonator, 15-sealing tool, 16-bridge plug, 17-pressure electronic control unit. DETAILED DESCRIPTION

[0063] The present invention will be further described below in conjunction with the accompanying drawings and exemplary embodiments.

[0064] Reference Figure 1 The perforating self-filling liquid ball pressure conversion device of the present invention comprises a shell 1 and a plugging ball 6. The plugging ball 6 is made of an aluminum-magnesium alloy material soluble in chloride ions. The shell 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 for threaded connection with a pressure initiator 10 or a pressure electronic control unit 17. A plugging seat 2 is provided inside the large-diameter section 1001. The plugging seat 2 is located at the bottom of the large-diameter section 1001. An internal thread for threaded connection with an oil pipe 9 is provided on the inner wall of the large-diameter section 1001 above the plugging seat 2.

[0065] A conical hole 7 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 7 to seal the conical hole 7. The large hole of the conical hole 7 faces the top of the shell 1. A blind hole 3 is axially provided at the bottom of the conical hole 7, 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 7 is connected with the annulus in the well outside 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 7.

[0066] Perforating pipe string embodiment 1:

[0067] like Figure 2 As shown, the perforating pipe string includes a deeper short section 8, a tubing 9, a self-filling liquid ball pressure conversion device 01 for perforating, a pressure electronic control unit 17, a battery pack 12, a perforating gun 11, an electronic delayed detonation device 13, an electronic selective detonation device 14, a sealing tool 15 and a bridge plug 16.

[0068] The deeper short joint 8, the oil pipe 9, the self-filling liquid ball pressure conversion device 01 for perforating and the pressure electronic control unit 17 are connected in sequence from top to bottom, and the battery pack 12 is connected to the tail end of the pressure electronic control unit 17, and the battery pack 12 is electrically connected to the pressure electronic control unit 17. In this embodiment, there are three perforating guns 11 and two electronic delayed detonating devices 13. The perforating gun 11 at the top is connected to the tail end of the battery pack 12, and the tail end of the perforating gun 11 at the bottom is connected to the electronic selective detonating device, and the electronic delayed detonating device 13 is connected between adjacent perforating guns 11. The top end of the sealing tool 15 is connected to the tail end of the electronic selective detonating device 14, and the tail end is connected to the bridge plug 16. The battery pack 12 is electrically connected to the electronic selective detonating device 14, and the electronic selective detonating device 14 is electrically connected to the sealing tool 15 and each electronic delayed detonating device 13.

[0069] The pressure electronic control unit 17 can adopt a pressure sensor. When the pressure is pressed and detonated, because the sealing ball 6 closes the connection with the annulus in the well, the pressure can only be transmitted to the pressure electronic control unit 17 from the pressure transmission hole 5. When the starting pressure is reached, the pressure electronic control unit 17 sends an electrical signal to the battery pack 12 to activate the battery pack 12. After activation, the battery pack 12 supplies power to the electronic selective detonating device 14 to start the electronic selective detonating device 14. The electronic selective detonating device 14 is used to control the start of the sealing tool 15 and the electronic delayed detonating device 13. In this embodiment, the sealing tool 15 adopts a gunpowder sealing tool. When the battery pack 12 supplies power to the sealing tool 15, the sealing gunpowder in the sealing tool 15 will be activated, and then the force generated by the sealing gunpowder will be used to seal the bridge plug 16 in the well, so as to complete the sealing in the well. Due to the sealing effect of the bridge plug 16, the oil and gas seeping from the formation after perforating will not flow to the well.

[0070] At the same time, the present invention also provides a perforation process, based on the above-mentioned perforation pipe string, comprising the following steps:

[0071] S1 lowers the perforating string into the well;

[0072] S2 When the deeper short section 8 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 7 of the self-filling liquid ball pressure conversion device 01 for perforating, and pressure is pumped from the wellhead, and the pressure is transmitted from the pressure transmission hole 5 to the pressure electronic control unit 17;

[0073] S3 pressure electronic control unit 17 activates battery pack 12 after reaching the starting pressure, battery pack 12 supplies power to electronic selective detonating device 14, and electronic selective detonating device 14 starts;

[0074] The S4 electronically selected detonator 14 activates the setting gunpowder in the setting tool 15 to start the setting tool 15, and the setting tool 15 sets the bridge plug 16 in the well. After the setting is completed, the bridge plug 16 is separated from the setting tool 15;

[0075] S5 electronic selective detonating device 14 activates multiple electronic delayed detonating devices 13 respectively;

[0076] The electronic delayed detonator 13 activated in S6 excites the perforating gun 11 connected thereto after a delay of a predetermined time, and during the delay period, moves the corresponding perforating gun 11 to a designated depth formation to complete perforation of the corresponding depth formation;

[0077] S7 repeats step S6 until all the corresponding depth formations are perforated;

[0078] S8: magnesium chloride or calcium chloride is added from the wellhead, and the plugging balls 6 are dissolved by themselves, and then the perforating pipe string is recovered from the wellhead.

[0079] In the perforating process, through the cooperation of multiple electronic time-delay detonators 13 and multiple perforating guns 11, since the delay time of the electronic time-delay detonator 13 can be freely set, it is possible to perform perforating operations on formations of different depths at different times, thus completing multi-stage perforating operations. Compared with the traditional operation mode of only performing perforating once per time, the flexibility of the perforating operation is greatly improved.

[0080] After the entire perforating pipe string is lowered into the well, when the electronic selective detonating device 14 has activated all the electronic delayed detonating devices 13 respectively, if a problem occurs in the well, it is not suitable to continue the perforating operation. At this time, because all the perforating guns 11 are in a state of waiting to be activated, the entire perforating pipe string cannot be pulled out, which will cause certain problems. Therefore, a perforating process is also provided, based on the above perforating pipe string, including the following steps:

[0081] S1 lowers the perforating string into the well;

[0082] S2 When the deeper short section 8 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 7 of the self-filling liquid ball pressure conversion device 01 for perforating, and pressure is pumped from the wellhead, and the pressure is transmitted from the pressure transmission hole 5 to the pressure electronic control unit 17;

[0083] S3 The pressure electronic control unit 17 activates the battery pack 12 after reaching the starting pressure, and the battery pack 12 continues to supply power to the corresponding electronic selective detonating device 14 within a preset time period, and the electronic selective detonating device 14 starts;

[0084] The S4 electronically selected detonator 14 activates the setting gunpowder in the setting tool 15 to start the setting tool 15, and the setting tool 15 sets the bridge plug 16 in the well. After the setting is completed, the bridge plug 16 is separated from the setting tool 15, and then the battery pack 12 is in a standby state;

[0085] S5: moving the perforating pipe string until one of the perforating guns 11 moves to the corresponding depth formation, and performing pressure pumping from the wellhead. After the pressure electronic control unit 17 reaches the starting pressure, the battery pack 12 is activated. The battery pack 12 continuously supplies power to the electronic selective detonating device 14 within a preset time period. The electronic selective detonating device 14 activates the electronic time-delay detonating device 13 connected to the perforating gun 11. After the delay reaches a preset time, the perforating gun 11 is stimulated to complete the perforation of the corresponding depth formation. Then the battery pack 12 is in the standby state again.

[0086] S6 repeats step S5 until all the corresponding depth formations are perforated;

[0087] S7: magnesium chloride or calcium chloride is added from the wellhead, the plugging balls 6 are dissolved by themselves, and then the perforating string is recovered from the wellhead.

[0088] After adopting this technology, only one corresponding perforating gun 11 is activated at one time of pressure injection. If a problem occurs in the well during perforating, the perforating pipe string can be recovered in time.

[0089] Perforating pipe string embodiment 2:

[0090] like Figure 3 As shown, the perforating pipe string includes a deeper short section 8, a tubing 9, a self-filling liquid ball pressure conversion device 01 for perforating, a pressure detonator 10 and a perforating gun 11, which are connected in sequence from top to bottom. The deeper short section 8 is used to measure the lowering depth of the entire perforating pipe string.

[0091] The structure of the pressure initiator 10 is as follows: Figure 4 As shown, it includes a housing, a piston 102 , a firing pin 104 , a shear assembly and an initiator 105 .

[0092] The housing includes a first joint 101 and a second joint 103 that are axially connected. The right end of the first joint 101 is sealed and arranged inside the left end of the second joint 103 through a threaded connection, and a sealing ring is arranged at the sealing connection between the two to ensure the sealing effect. The detonator 105 is coaxially arranged inside the second joint 103, and the piston 102 is sealed and arranged inside the first joint 101 and the second joint 103. A firing pin 104 is detachably installed at one end of the piston 102 close to the detonator 105.

[0093] The shearing assembly is arranged between the outside of the piston 102 and the inside of the first joint 101 and the second joint 103, and is used to fix the position of the piston 102. In this embodiment, the shearing assembly includes a shearing sleeve 106 and a shearing pin 1061. In order to fix the position of the piston 102 by the shearing assembly, a first joint step surface is opened inside the first joint 101, and a second joint step surface is opened inside the second joint 103, and the large diameter section of the first joint step surface faces the second joint 103, while the large diameter section of the second joint step surface faces the first joint 101, so that the two large diameter sections are arranged opposite to each other, and the large diameter section of the first joint step surface and the large diameter section of the second joint step surface together constitute an installation cavity.

[0094] The piston 102 is located in the installation cavity, and the shear sleeve 106 is sleeved on the outer wall of the piston 102 and is located between the inner wall of the installation cavity and the outer wall of the piston 102. The piston 102 and the shear sleeve 106 are connected by multiple shear pins 1061. The shear pins 1062 can be broken when subjected to force. The outer diameter of the piston 102 is less than or equal to the inner diameter of the small diameter section corresponding to the step surface of the second joint. In this way, after the shear pins 1061 are sheared off when subjected to force, the piston 102 can move toward the detonator 105 without being affected by the step surface of the second joint, and then the firing pin 104 can be used to hit the detonator 105 smoothly.

[0095] When the entire perforating pipe string is lowered into the well, the conical hole 7, blind hole 3 and connecting hole 4 of the pressure conversion device 01 for perforating are connected to the inside and outside of the device to ensure the connection with the annulus in the well. When the pressure is pressed and detonated, the conical hole 7 is blocked by the blocking ball 6 to isolate the annulus in the well, and the pressure is transmitted from the pressure transmission hole 5 to the piston 102. The piston 102 transmits the pressure to the shear pin 1061, and the shear pin 1061 is sheared by force, so that the piston 102 is separated from the shear sleeve 106 and moves toward the detonator 105. The striker 104 hits the detonator 105 and activates the perforating gun 11. When pulling out, magnesium chloride or potassium chloride is thrown into the well, and the blocking ball 6 dissolves by itself when encountering chloride ions, so that the conical hole 7, blind hole 3 and connecting hole 4 The passage formed by the connecting hole is connected to the inside and outside of the device again to prevent blowouts or well kicks.

[0096] At the same time, the present invention also provides a perforation process, based on the above-mentioned perforation pipe string, comprising the following steps:

[0097] S1 lowers the perforating string into the well;

[0098] S2 When the deeper short section 8 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 tapered hole 7 of the self-filling liquid ball-dropping pressure conversion device 01 for perforating;

[0099] S3 performs pressure pumping from the wellhead, and the pressure is transmitted from the pressure transmission hole 5 to the piston 102, and the piston 102 transmits the pressure to the shear assembly;

[0100] S4 The shear assembly is broken by the force, and then the piston 102 drives the striker 104 to hit the detonator 105, activating the perforating gun 11 to complete the perforation of the formation at the specified depth;

[0101] After the perforation of the formation at this depth is completed in S5, magnesium chloride or calcium chloride is added into the well, the plugging balls 6 dissolve by themselves, and then the perforation string is recovered from the wellhead.

[0102] 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, Features: It comprises a shell (1) and a blocking ball (6); The top end of the housing (1) is used to connect to the oil pipe (9), and the bottom end is used to connect to the pressure detonator (10) or the pressure electronic control unit (17); A blocking seat (2) is arranged inside the shell (1), a conical hole (7) is provided at the center of the top of the blocking seat (2), and the large hole of the conical hole (7) 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 (7) is connected with 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 (7) to block the tapered hole (7), and the blocking ball (6) is made of a material that is soluble in chloride ions.

2. The perforating self-filling liquid ball pressure conversion device according to claim 1, Features: The housing (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 being threadedly connected to the pressure detonator (10); 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 (9).

3. The perforating self-filling liquid ball pressure conversion device according to claim 1 or 2, Features: A blind hole (3) is axially provided at the bottom of the tapered hole (7); and the communicating hole (4) is radially provided along the outer wall of the housing (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 (7).

4. The perforating self-filling liquid ball pressure conversion device according to claim 1, Features: The material soluble in chloride ions used to make the blocking ball (6) is an aluminum-magnesium alloy material.

5. A perforating pipe string, comprising a relatively deep short section (8), an oil pipe (9) and a perforating gun (11), Features: It also comprises a self-filling liquid ball pressure conversion device (01) for perforating as claimed in any one of claims 1 to 4, a battery pack (12), an electronic time-delay detonation device (13), an electronic selective detonation device (14), a sealing tool (15), a bridge plug (16) and a pressure electronic control unit (17); The relatively deep short joint (8), the oil pipe (9), the self-filling liquid ball pressure conversion device for perforation (01), and the pressure electronic control unit (17) are connected in sequence from top to bottom; The battery pack (12) is connected to the tail end of the pressure electronic control unit (17), there are multiple perforating guns (11), and the electronic delayed detonation device (13) is connected between adjacent perforating guns (11), the perforating gun (11) at the top is connected to the tail end of the battery pack (12), the tail end of the perforating gun (11) at the bottom is connected to the electronic selective detonation device (14), the top end of the setting tool (15) is connected to the tail end of the electronic selective detonation device (14), and the tail end is connected to the bridge plug (16); The pressure electronic control unit (17) is electrically connected to the battery pack (12), the battery pack (12) is electrically connected to the electronic selective detonating device (14), and the electronic selective detonating device (14) is electrically connected to the setting tool (15) and each electronic delayed detonating device (13).

6. A perforating process, based on the perforating string according to claim 5, It is characterized in that The following steps are involved: S1 lowers the perforating string into the well; S2 When the deeper short section (8) 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 (7) of the self-filling liquid ball pressure conversion device (01) for perforating, and pressure is pumped from the wellhead, and the pressure is transmitted from the pressure transmission hole (5) to the pressure electronic control unit (17); When the S3 pressure electronic control unit (17) reaches the starting pressure, the battery pack (12) is activated, and the battery pack (12) supplies power to the electronic selective detonating device (14), and the electronic selective detonating device (14) is started; The S4 electronic selective detonator (14) activates the setting gunpowder in the setting tool (15) to start the setting tool (15), and the setting tool (15) sets the bridge plug (16) in the well. After the setting is completed, the bridge plug (16) is separated from the setting tool (15); S5 electronic selective detonating device (14) activates the plurality of electronic delayed detonating devices (13) respectively; The electronic time-delay detonator (13) activated by S6 excites the perforating gun (11) connected thereto after a delay of a predetermined time, and during the delay period, the corresponding perforating gun (11) is moved to a corresponding depth formation to complete perforation of the corresponding depth formation; S7 repeats step S6 until all the corresponding depth formations are perforated; S8: magnesium chloride or calcium chloride is added from the wellhead, the plugging balls (6) dissolve by themselves, and then the perforation string is recovered from the wellhead.

7. A perforating process, based on the perforating string according to claim 5, It is characterized in that The following steps are involved: S1 lowers the perforating string into the well; S2 When the deeper short section (8) 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 (7) of the self-filling liquid ball pressure conversion device (01) for perforating, and pressure is pumped from the wellhead, and the pressure is transmitted from the pressure transmission hole (5) to the pressure electronic control unit (17); The S3 pressure electronic control unit (17) activates the battery pack (12) after reaching the starting pressure, and the battery pack (12) continuously supplies power to the corresponding electronic selective detonating device (14) within a preset time period, and the electronic selective detonating device (14) starts; The S4 electronic selective detonator (14) activates the setting gunpowder in the setting tool (15) to start the setting tool (15), and the setting tool (15) sets the bridge plug (16) in the well. After the setting is completed, the bridge plug (16) is separated from the setting tool (15), and then the battery pack (12) is in a standby state; S5: moving the perforating pipe string until one of the perforating guns (11) moves to the corresponding depth formation, and performing pressure pumping from the wellhead. After the pressure electronic control unit (17) reaches the starting pressure, the battery pack (12) is activated. The battery pack (12) continuously supplies power to the electronic selective detonating device (14) within a preset time period. The electronic selective detonating device (14) activates the electronic time-delay detonating device (13) connected to the perforating gun (11). After the delay reaches a predetermined time, the perforating gun (11) is activated to complete the perforation of the corresponding depth formation. Then, the battery pack (12) is in a standby state again. S6 repeats step S5 until all the corresponding depth formations are perforated; S7: magnesium chloride or calcium chloride is added from the wellhead, and the plugging balls (6) are dissolved by themselves, and then the perforation string is recovered from the wellhead.

8. A perforating pipe string, comprising a relatively deep short joint (8), a tubing (9), a perforating gun (11) and a pressure detonator (10), Features: It also comprises a self-filling liquid ball pressure conversion device (01) for perforating as claimed in any one of claims 1 to 4; The relatively deep short joint (8), the oil pipe (9), the self-filling liquid ball pressure conversion device for perforating (01), the pressure detonator (10) and the perforating gun (11) are connected in sequence from top to bottom; The pressure detonator (10) comprises a housing, a piston (102), a firing pin (104), a shearing assembly and a detonator (105); The housing comprises a first joint (101) and a second joint (103) which are axially connected, the right end of the first joint (101) is sealedly arranged inside the left end of the second joint (103), and the detonator (105) is coaxially arranged inside the second joint (103); the piston (102) is sealedly arranged inside the first joint (101) and the second joint (103); The shearing assembly is arranged between the outside of the piston (102) and the inside of the first joint (101) and the second joint (103), and is used to fix the position of the piston (102). The shearing assembly can be broken when subjected to force. The firing pin (104) is detachably mounted on one end of the piston (102) close to the detonator (105).

9. The perforating string according to claim 8, Features: The shear assembly comprises a shear sleeve (106) and a shear pin (1061); A first joint step surface is provided inside the first joint (101), a second joint step surface is provided inside the second joint (103), the large diameter section of the first joint step surface faces the second joint (103), the large diameter section of the second joint step surface faces the first joint (101), and the large diameter section of the first joint step surface and the large diameter section of the second joint step surface together form a mounting cavity; The piston (102) is located in the installation cavity, the shear sleeve (106) is located between the inner wall of the installation cavity and the outer wall of the piston (102), and the piston (102) and the shear sleeve (106) are connected via a plurality of shear pins (1061); The outer diameter of the piston (102) is smaller than or equal to the inner diameter of the small diameter section corresponding to the step surface of the second joint.

10. A perforating process, based on the perforating string according to claim 8, It is characterized in that The following steps are involved: S1 lowers the perforating string into the well; S2 When the deeper short section (8) 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 tapered hole (7) of the self-filling liquid ball-dropping pressure conversion device (01) for perforating; S3 performs pressure pumping from the wellhead, and the pressure is transmitted from the pressure transmission hole (5) to the piston (102), and the piston (102) transmits the pressure to the shear assembly; The S4 shear assembly is broken by force, and then the piston (102) drives the striker (104) to hit the detonator (105), thereby activating the perforating gun (11) to complete the perforation of the formation at a specified depth; After the perforation of the formation at this depth is completed in S5, magnesium chloride or calcium chloride is added into the well, the plugging balls (6) dissolve by themselves, and then the perforation string is recovered from the wellhead.

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