Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
It should be understood that, in the following embodiments of the present invention, reference is made to the directions shown in the drawings, and these words of limitation are merely for convenience of description and do not represent limitations on the specific embodiments of the present invention.
The embodiment of the invention provides a liquid explosive injection and detonation device for oil and gas reservoir explosion fracturing, which comprises a driving unit 1, a cylinder barrel 2, a liquid explosive injection and detonation unit 3, a driving pressure transmission unit 4, a central steel column 5, a perforation section elastic sealing unit 6 and a first compression ring 7; the driving unit 1 is positioned in the left end of the cylinder barrel 2; the cylinder barrel 2 is fixedly connected with the central steel column 5; the liquid explosive injection and explosion starting unit 3 is positioned in the cylinder barrel 2; the perforation section elastic sealing units 6 and the first compression rings 7 are sleeved outside the central steel column 5; the driving pressure transmission unit 4 is positioned between the liquid explosive injection and explosion starting unit 3 and the first compression ring 7 and penetrates through the joint of the cylinder barrel 2 and the central steel column 5.
The driving unit 1 forms system driving pressure, under the action of the driving pressure, as the liquid explosive injection channel in the invention is in a disconnected state, the injection process of the liquid explosive injection and explosion starting unit 3 cannot be started at first, and the perforation section elastic sealing unit 6 preferably and automatically starts the sealing of the target perforation section; the liquid explosive injection channels can be communicated only after the pressure-resistant sealing of the two sides of the perforation section is finished, and at the moment, the liquid explosive injection and explosion starting unit 3 is automatically started under the continuous action of the driving unit 1; when the liquid explosive in the liquid explosive injection and explosion starting unit 3 is completely extruded and the state of injection pressure is kept, the liquid explosive injected into the stratum is automatically started, transferred and detonated; according to the invention, in a short time, the oil-gas fracturing device is respectively and automatically started according to the working sequence of the system design to reach the required working state, and the set functions are completed, so that the explosion fracturing of the oil-gas layer is realized.
Example 1
The embodiment 1 of the invention provides a liquid explosive injection and detonation device for oil and gas reservoir explosion fracturing, which comprises a driving unit 1, a cylinder barrel 2, a liquid explosive injection and detonation unit 3, a driving pressure transmission unit 4, a central steel column 5, a perforation section elastic sealing unit 6 and a first compression ring 7, as shown in figure 1; the driving unit 1 is positioned in the left end of the cylinder barrel 2; the cylinder barrel 2 is fixedly connected with the central steel column 5; the liquid explosive injection and explosion starting unit 3 is positioned in the cylinder barrel 2; the perforation section elastic sealing units 6 and the first compression rings 7 are sleeved outside the central steel column 5; the driving pressure transmission unit 4 is positioned between the liquid explosive injection and explosion starting unit 3 and the first compression ring 7 and penetrates through the joint of the cylinder barrel 2 and the central steel column 5.
The driving unit 1 is used for generating pressure to push the liquid explosive injection and detonation unit 3 to move rightwards, and the pressure is applied to the perforation section elastic sealing unit 6 through the driving pressure transmission unit 4 in the process of moving the liquid explosive injection and detonation unit 3; after the perforation section elastic sealing unit 6 is compressed; the first pressing ring 7 moves rightward along the central steel column 5 while being pressed until the axial compression of the perforation section elastic sealing unit 6 reaches the upper limit, and then the first pressing ring 7 stops moving, at this time, the liquid explosive in the liquid explosive injection and detonation unit 3 is injected into the stratum at high pressure through the liquid explosive injection channel, and after the injection is completed, the liquid explosive is detonated.
The drive unit 1 comprises a high-pressure pump, a high-pressure pipe 108, a spacer 109, a third upper connector 110; the first piston 31 is provided with a fourth liquid explosive injection hole 311 for communicating the inner cavity 113 of the third upper connector 110 with the first liquid explosive bin 35, and the first piston 31 is fixed on the right side of the third upper connector 110 through a fourth shear pin 312; the third upper connector 110 is positioned at the left end of the cylinder barrel 2; the high-pressure pump is communicated with a third upper connector 110 through a high-pressure pipe 108; the spacer 109 is located within the high pressure tube 108; the area between the spacer 109 and the first piston 31 is used for a second liquid explosive cartridge 111 for storing liquid explosive.
The spacer 109 may be a spacer ball.
The left end surface of the first piston 31 is a spherical concave surface, so that after the liquid explosive in the second liquid explosive bin 111 is injected; the spacer 109 is fully mated with the first piston 31 to effect shearing of the fourth shear pin 312.
The third upper connector 110 is provided with a safety hole, and when the pressure exceeds the safety range, the pressure is relieved through the safety hole.
The liquid explosive injection and explosion starting unit 3 is used for injecting and detonating the liquid explosive and comprises a first piston 31, a second piston 32, a hollow steel column 33 and an explosion starting assembly 34; the first piston 31 and the second piston 32 are movably arranged in the cylinder barrel 2 in sequence from left to right, and a first liquid explosive bin 35 is formed between the first piston and the second piston; the left end of the hollow steel column 33 is positioned on the second piston 32 and is communicated with the first liquid explosive bin 35 through the second piston 32; the right end of the hollow steel column 33 extends into the central steel column 5 and is fixed with the central steel column 5 by a first shear pin 52; the initiation assembly 34 is disposed within the first piston 31 and within the first liquid explosive cartridge 35.
The explosion initiating component 34 is used for realizing the detonation of the liquid explosive after the injection of the liquid explosive is completed, and comprises an explosion pressing head 341, an explosion initiating striker 342, an explosion initiating bullet 343 and a second shear pin 344; the explosion head 341 is fixed on the first piston 31 through a second shear pin 344; the detonation striker 342 is positioned on the left end face of the explosion head 341; the explosion proof bullet 343 is arranged at the left side of the explosion head 341.
Specifically, the right end of the first piston 31 is provided with a large central hole for mounting the explosion initiating mechanism 34, and the left end is provided with a small central hole for mounting the detonation striker 342. The right end of the second piston 32 is provided with a large central hole for installing the hollow steel column 33, and the left end is provided with a small central hole, and the large central hole is communicated with the small central hole. The left end of the hollow steel column 33 is arranged in a large central hole at the right end of the second piston 32 and is fixedly connected with the second piston by threads; the central hole of the hollow steel column 33 is coaxially arranged with the central hole of the second piston 32, has the same aperture as the small central hole arranged at the left end of the second piston 32, is mutually communicated and is communicated with the first liquid explosive bin 35; the right end of the hollow steel column 33 extends into the central hole of the central steel column 5; the explosion initiating mechanism 34 is coaxially arranged in a large central hole at the right end of the first piston 31, and the explosion pressing head 341 of the explosion initiating mechanism 34 extends out of the right end face of the first piston 31 and is positioned in the left end of the first liquid explosive bin 35.
The explosion head 341 is fixed on the first piston 31 through a second shear pin 344; the detonation hammer 342 is arranged in a small central hole at the left end of the first piston 31 and is positioned at the left side of the detonation mechanism 34; the explosion proof bullet 343 is disposed at the left end of the central hole of the explosion head 341.
A T-shaped first liquid explosive injection hole 331 is arranged in the hollow steel column 33; the central steel column 5, the first compression ring 7 and the first liquid explosive injection hole 331 are respectively provided with a second liquid explosive injection hole 51 and a third liquid explosive injection hole 71.
Before the liquid explosive is injected, the first liquid explosive injection hole 331, the second liquid explosive injection hole 51, and the third liquid explosive injection hole 71 are not communicated, and finally, the first liquid explosive injection hole 331, the second liquid explosive injection hole 51, and the third liquid explosive injection hole 71 are communicated to form a liquid explosive injection channel under the action of the driving unit 1 as a power source, and then, the first liquid explosive bin 35 is injected into the stratum through the liquid explosive injection channel under the pressure of the first piston 31.
The left end of the hollow steel column 33 is coaxially arranged in the central inner hole of the right end of the second piston 32 and is fixedly connected with threads; the right end of the hollow steel column 33 is coaxially arranged in the central inner hole of the central steel column 5; the hollow steel column 33 and the central steel column 5 are fixed by a first shear pin 52.
The first shear pin 52 serves to prevent the hollow steel column 33 from reciprocating within the central steel column 5 before shipping or starting operation, thereby preventing the second piston 32 from reciprocating within the cylinder 2.
The first liquid explosive bin 35 is filled with liquid explosive in advance, and when the driving unit 1 pushes the first piston 31 to move rightwards; the first piston 31 generates pressure on the liquid explosive and pushes the second piston 32 to move rightwards; the second piston 32 applies pressure to the first elastic sealing ring 61 through the steel column piston; the first elastic sealing ring 61 applies pressure to the first compression ring 7 while being axially compressed by the pressure; the first compression ring 7 moves rightwards after being pressed, and pushes the supporting sleeve 62 to move rightwards; the support sleeve 62 in turn applies pressure to the second elastic sealing ring 63; the second elastic sealing ring 63 is compressed axially after being pressed, and the first compression ring 7 is displaced rightward by the difference between the axial compression of the first elastic sealing ring 61 and the second elastic sealing ring 63 and the displacement generated rightward, and is matched with the hollow steel column 33 to form a liquid explosive injection channel, so that the liquid explosive in the first liquid explosive bin 35 is injected into the stratum; after the injection of the liquid explosive in the first liquid explosive bin 35 is completed; the initiation mechanism 34 initiates detonation of the liquid explosive.
After the first elastic sealing ring 61 and the second elastic sealing ring 63 are compressed, they are radially expanded and extruded to the inner wall of the well casing 10 to form a pressure-resistant seal on two sides of the perforation section, and after the liquid explosive enters the sealed perforation section through the liquid explosive injection channel, the liquid explosive is injected into the stratum through the perforation holes on the well casing 10.
When the first piston 31 moves rightwards and simultaneously drives the explosion pressing head 341 to move rightwards, and when the liquid explosive in the first liquid explosive bin 35 is completely extruded, the explosion pressing head 341 is in contact with the left end face of the second piston 32, the generated pressure shears the second shear pin 344, at this time, the explosion pressing head 341 carries the explosion starting bullet 343 under the action of the pressure and moves leftwards along the large central hole of the first piston 31 until the explosion starting bullet 343 collides with the detonation firing pin 342, the explosion starting bullet 343 is exploded, and the liquid explosive reserved in the liquid explosive injection channel and the perforation section is used as a booster explosive to detonate the liquid explosive injected into the stratum.
The perforation section elastic sealing unit 6 comprises a first elastic sealing ring 61, a supporting sleeve 62 and a second elastic sealing ring 63; the first elastic sealing ring 61, the supporting sleeve 62 and the second elastic sealing ring 63 are sleeved outside the central steel column 5 in sequence from left to right; the first compression ring 7 is located between the first elastic sealing ring 61 and the supporting sleeve 62.
Further, still include second clamping ring 8, second clamping ring 8 cover is established outside center steel column 5 and is located between the right-hand member face of steel column piston and first elastic sealing washer 61, like this, the pressure that the steel column piston applyed is evenly applied to first elastic sealing washer 61 through second clamping ring 8 for the axial compression of first elastic sealing washer 61 is more stable.
The cylinder barrel 2 is fixedly connected with the central steel column 5 through the middle connector 22; the steel column piston penetrates the intermediate joint 22.
Specifically, 4 to 12 process through holes are uniformly distributed on the middle connector 22 along the axial ring shape, and 4 to 12 steel column pistons penetrate through the middle connector 22 and are propped against the left end face of the second compression ring 8; the middle connector 22 is a core component for connecting and fixing the cylinder barrel 2 and the central steel column 5, the internal thread at the right end of the cylinder barrel 2 is fixedly connected with the external thread at the left end of the middle connector 22, and the internal thread of the middle connector 22 is fixedly connected with the external thread at the left end of the central steel column 5. The steel column piston is positioned between the second piston 32 and the second compression ring 8 and penetrates through 4 to 12 process holes arranged on the middle connector 22; the left end of the steel column piston is propped against the right end face of the second piston 32, and the right ends of all (4-12) steel column pistons are propped against the left end face of the second compression ring 8.
Further, the device also comprises a guide head 9, wherein the guide head 9 is sleeved at the right end of the central steel column 5.
The cylinder 2 is provided with a safety hole 21 and the second upper connector 106 is also provided with a safety hole, so that if the pressure in the cylinder 2 exceeds the safety range, the pressure is relieved through the safety hole 21.
The working process of the automatic starting sequence of each unit of the embodiment of the invention is as follows:
(1) Actuation of the drive unit 1:
According to the weight of the liquid explosive to be injected, at least one high-pressure pipe 108 is sleeved on a third upper joint 110, the invention is conveyed to a target position of a shaft sleeve 10, namely a target perforation section, the liquid explosive is injected into a second liquid explosive bin 111 in the high-pressure pipe 108 until the designed explosive amount is reached, a separator 109 is placed in the high-pressure pipe 108, then the high-pressure pipe 108 is pressurized by a high-pressure pump to inject pressure liquid, at this time, the pressure liquid generates driving pressure F, the separator 109 moves rightwards under the pressure of the pressure liquid, the pressure is generated on the liquid explosive injected into the second liquid explosive bin 111 before, the first piston 31 cannot displace due to the limiting effect of a fourth shearing pin 312, the liquid explosive is injected into the first liquid explosive bin 35 through a fourth liquid explosive injection hole 311 on the first piston 31, at this time, the liquid explosive injection channel is in a disconnected state, and at this time, the driving unit 1 is started, namely the invention is started to work.
It should be noted that, before going into the well, a portion of the liquid explosive is injected into the first liquid explosive bin 35 in advance as an isolation explosive, so as to isolate the first piston 31 from the second piston 31.
(2) The sealing process of the perforation section is started:
After the driving unit 1 of the invention is started, the liquid explosive injection channel is in a disconnected state, so that the perforation section elastic sealing unit 6 for sealing the target perforation section is preferentially and automatically started under the action of the driving pressure F.
After the liquid explosive in the first liquid explosive bin 35 transfers the driving pressure F to the second piston 32 and the transferred pressure exceeds the bearing of the first shear pin 52, the first shear pin 52 is sheared, the second piston 32 moves rightwards to transfer the pressure to the steel column piston, the steel column piston transfers the pressure to the second compression ring 8 through the middle connector 22, the second compression ring 8 transfers the pressure to the first elastic sealing ring 61, the first elastic sealing ring 61 transfers the pressure to the first compression ring 7, the first compression ring 7 transfers the pressure to the second elastic sealing ring 63 through the support sleeve 62, and the second elastic sealing ring 63 transfers the pressure to the guide head 9.
In the transmission process of the pressure, the driving pressure F continuously rises to enable the second piston 32, the first elastic sealing ring 61, the supporting sleeve 62 and the second elastic sealing ring 63 to displace rightwards, meanwhile, the two sides of the first elastic sealing ring 61 and the second elastic sealing ring 63 are extruded by axial high pressure, the axial widths of the first elastic sealing ring 61 and the second elastic sealing ring 63 become smaller, the first elastic sealing ring 61 and the second elastic sealing ring 63 expand radially until being tightly extruded to the inner wall of the well casing 10, high-pressure-resistant sealing of two ends of a perforation section is achieved, and when the axial compression deformation of the first elastic sealing ring 61 and the second elastic sealing ring 63 reaches the deformation amount required by design, the sealing pressure-resistant level reaching the design requirement is guaranteed, which is a key node from the completion of sealing to the beginning of injection in the next step.
(3) Automatic start of liquid explosive injection into the formation:
When the axial compression deformation of the first elastic sealing ring 61 and the second elastic sealing ring 63 reaches the deformation amount required by design, under the action of the driving pressure F, the two ends of the first liquid explosive injection pore canal 331 are in butt joint communication with the second liquid explosive injection pore canal 51, and the second liquid explosive injection pore canal 51 is in butt joint communication with the third liquid explosive injection pore canal 71 on the first compression ring 7, so that the integral communication of the liquid explosive injection channel is realized, and the communication of the liquid explosive injection channel, perforation holes and an oil-gas stratum is realized, and at the moment, the liquid explosive starts to be injected into the stratum.
Under the action of the driving pressure F, the liquid explosives in the second liquid explosive cartridge 111 and the first liquid explosive cartridge 35 are gradually injected into the stratum through the communicated liquid explosive injection passage.
(4) Automatic starting of the instant pressure explosion, explosion propagation and explosion fracturing process:
After all the liquid explosive in the second liquid explosive bin 111 is extruded, the spacer 109 contacts with the left end face of the first piston 1, the fourth liquid explosive injection hole 311 is closed, the pressure of the first piston 31 rises, the fourth shear pin 312 is sheared after exceeding the upper limit of the load of the fourth shear pin 312, and the first piston 31 moves rightward to extrude all the liquid explosive in the first liquid explosive bin 35.
The liquid explosive in the first liquid explosive bin 35 is completely extruded, under the continuous action of the driving pressure F, the explosion head 341 impacts the left end face of the second piston 32 to shear the second shearing pin 344 at the moment of maintaining the injection pressure, at this time, the explosion head 341 carries the explosion initiating bomb 343 under the pressure action, moves leftwards along the large central hole of the first piston 31, the explosion initiating striker 342 collides with the explosion initiating bomb 343, the explosion initiating bomb 343 is exploded, the liquid explosive reserved in the liquid explosive injection channel and the perforating section serves as a booster explosive, and the liquid explosive injected into the oil-gas formation is detonated, so that the explosion fracturing in the layer is realized.
Because the liquid explosive remained in the well casing 10 of the sealed perforation section is detonated and then is attached to the liquid explosive in the stratum outside the well casing 10, the impact force generated after the detonation can be mutually counteracted, and the impact on the well casing 10 is reduced; the injection is completed, instant detonation of injection pressure is maintained, and the mixing of liquid explosive in the stratum with water and oil and the loss of the liquid explosive in the stratum can be effectively reduced, so that the liquid explosive injected into the stratum can be fully detonated, and the problem that a considerable amount of explosive or explosive mixture remains in the stratum because the liquid explosive cannot be fully detonated is solved.
The liquid explosive is injected into perforation holes and cracks in stratum around the perforation holes by taking the shaft as the shaft center, a detonation area with the diameter of 10-30 meters can be generated after explosion according to the explosive amount of the injected liquid explosive, and the explosion stress wave can extend for 30-60 meters, so that a netlike crack area can be generated around the shaft within the range of about 30-60 meters, and the effect of volume fracturing is achieved.
Explosive fracturing in a stratum is a dynamic process, and under the impact load action of a certain loading rate, a plurality of irregular radial cracks are formed, and the crack surface is no longer perpendicular to the direction of the minimum main stress. Due to the shearing action of ground stress, an off-axis effect can be generated between the fracture surfaces, so that small dislocation occurs between the fracture wall surfaces, and the fracture cannot be restored to be closed in situ after unloading, so that the fracture with higher permeability is formed. Meanwhile, the rock generates unrecoverable plastic deformation under the action of high pressure exceeding the yield limit, so that the crack still maintains a certain residual seam width after unloading. In addition, the stress wave flakes off the seam rock, producing a certain rock chip; meanwhile, the high-temperature and high-pressure gas can damage the rock structure near the fracture surface in the process of extending the fracture, so that certain rock fragments are generated, and the fragments also play a role in supporting the micro-fracture.
Example 2
The embodiment 2 of the invention provides a liquid explosive injection and detonation device for oil and gas reservoir explosion fracturing, which comprises a driving unit 1, a cylinder barrel 2, a liquid explosive injection and detonation unit 3, a driving pressure transmission unit 4, a central steel column 5, a perforation section elastic sealing unit 6 and a first compression ring 7, as shown in fig. 2-4; the driving unit 1 is positioned in the left end of the cylinder barrel 2; the cylinder barrel 2 is fixedly connected with the central steel column 5; the liquid explosive injection and explosion starting unit 3 is positioned in the cylinder barrel 2; the perforation section elastic sealing units 6 and the first compression rings 7 are sleeved outside the central steel column 5; the driving pressure transmission unit 4 is positioned between the liquid explosive injection and explosion starting unit 3 and the first compression ring 7 and penetrates through the joint of the cylinder barrel 2 and the central steel column 5.
The driving unit 1 is used for generating pressure to push the liquid explosive injection and detonation unit 3 to move rightwards, and the pressure is applied to the perforation section elastic sealing unit 6 through the driving pressure transmission unit 4 in the process of moving the liquid explosive injection and detonation unit 3; after the perforation section elastic sealing unit 6 is compressed, the first compression ring 7 moves rightward along the central steel column 5 while being subjected to pressure until the axial compression of the perforation section elastic sealing unit 6 reaches the upper limit, and then the first compression ring 7 stops moving, and at this time, the liquid explosive in the liquid explosive injection and detonation unit 3 is injected into the stratum through the liquid explosive injection channel under high pressure, and after the injection is completed, the liquid explosive is detonated.
The driving unit 1 comprises an upper second upper connector 106, a high-pressure pump and a third shear pin 105; the first piston 31 is fixed on the right side of the second upper connector 106 by a third shear pin 105; the second upper connector 106 is positioned at the left end of the cylinder barrel 2 and forms a liquid bin 107 with the first piston 31; the high pressure pump communicates with the liquid reservoir 107 via a second upper connection head 106.
The third shear pin 105 is used to prevent the first piston 31 from bouncing back and forth until transport or start of operation.
The liquid explosive injection and explosion starting unit 3 comprises a first piston 31, a second piston 32, a hollow steel column 33 and an explosion starting assembly 34; the first piston 31 and the second piston 32 are movably arranged in the cylinder barrel 2 in sequence from left to right, and a first liquid explosive bin 35 is formed between the first piston and the second piston; the left end of the hollow steel column 33 is positioned on the second piston 32 and is communicated with the first liquid explosive bin 35 through the second piston 32; the right end of the hollow steel column 33 extends into the central steel column 5 and is fixed with the central steel column 5by a first shear pin 52; the initiation assembly 34 is disposed within the first piston 31 and within the first liquid explosive cartridge 35.
The explosion initiating assembly 34 comprises an explosion pressing head 341, an explosion initiating striker 342, an explosion initiating bullet 343 and a second shear pin 344; the explosion head 341 is fixed on the first piston 31 through a second shear pin 344; the detonation striker 342 is positioned on the left end face of the explosion head 341; the explosion proof bullet 343 is arranged at the left side of the explosion head 341.
Specifically, the right end of the first piston 31 is provided with a large central hole for mounting the explosion initiating mechanism 34, and the left end is provided with a small central hole for mounting the detonation striker 342. The right end of the second piston 32 is provided with a large central hole for installing the hollow steel column 33, and the left end is provided with a small central hole, and the large central hole is communicated with the small central hole. The left end of the hollow steel column 33 is arranged in a large central hole at the right end of the second piston 32 and is fixedly connected with the second piston by threads; the central hole of the hollow steel column 33 is coaxially arranged with the central hole of the second piston 32, has the same aperture as the small central hole arranged at the left end of the second piston 32, is mutually communicated and is communicated with the first liquid explosive bin 35; the right end of the hollow steel column 33 extends into the central hole of the central steel column 5; the explosion initiating mechanism 34 is coaxially arranged in a large central hole at the right end of the first piston 31, and the explosion pressing head 341 of the explosion initiating mechanism 34 extends out of the right end face of the first piston 31 and is positioned in the left end of the first liquid explosive bin 35.
The explosion head 341 is fixed on the first piston 31 through a second shear pin 344; the detonation hammer 342 is arranged in a small central hole at the left end of the first piston 31 and is positioned at the left side of the detonation mechanism 34; the explosion proof bullet 343 is disposed at the left end of the central hole of the explosion head 341.
A T-shaped first liquid explosive injection hole 331 is arranged in the hollow steel column 33; the central steel column 5, the first compression ring 7 and the first liquid explosive injection hole 331 are respectively provided with a second liquid explosive injection hole 51 and a third liquid explosive injection hole 71.
Before the liquid explosive is injected, the first liquid explosive injection hole 331, the second liquid explosive injection hole 51, and the third liquid explosive injection hole 71 are not connected, and under the action of the driving unit 1 as a power source, finally, the first liquid explosive injection hole 331, the second liquid explosive injection hole 51, and the third liquid explosive injection hole 71 are connected to form a liquid explosive injection channel, and then, under the pressure of the first piston 31, the first liquid explosive bin 35 is injected into the stratum at high pressure through the liquid explosive injection channel.
The left end of the hollow steel column 33 is coaxially arranged in the central inner hole of the right end of the second piston 32 and is fixedly connected with threads; the right end of the hollow steel column 33 is coaxially arranged in the central inner hole of the central steel column 5; the hollow steel column 33 and the central steel column 5 are fixed by a first shear pin 52.
The first shear pin 52 serves to prevent the hollow steel column 33 from reciprocating within the central steel column 5 before shipping or starting operation, thereby preventing the second piston 32 from reciprocating within the cylinder 2.
The first liquid explosive bin 35 is filled with liquid explosive in advance, and when the driving unit 1 pushes the first piston 31 to move rightwards; the first piston 31 generates pressure on the liquid explosive and pushes the second piston 32 to move rightwards; the second piston 32 applies pressure to the first elastic sealing ring 61 through the steel column piston; the first elastic sealing ring 61 applies pressure to the first compression ring 7 while being axially compressed by the pressure; the first compression ring 7 moves rightwards after being pressed, and pushes the supporting sleeve 62 to move rightwards; the support sleeve 62 in turn applies pressure to the second elastic sealing ring 63; the second elastic sealing ring 63 is compressed axially after being pressed, and the first compression ring 7 is displaced rightward by the difference between the axial compression of the first elastic sealing ring 61 and the second elastic sealing ring 63 and the displacement generated rightward, and is matched with the hollow steel column 33 to form a liquid explosive injection channel, so that the liquid explosive in the first liquid explosive bin 35 is injected into the stratum; after the injection of the liquid explosive in the first liquid explosive bin 35 is completed; the initiation mechanism 34 initiates detonation of the liquid explosive.
The first elastic sealing ring 61 and the second elastic sealing ring 63 are compressed and then expand in the radial direction, thus a perforation section is formed between the first elastic sealing ring and the well casing 10, and after entering the perforation section through the liquid explosive injection channel, the liquid explosive is injected into the stratum through a plurality of perforation holes on the well casing 10 at high pressure.
When the first piston 31 moves rightwards and simultaneously drives the explosion pressing head 341 to move rightwards, and when the liquid explosive in the first liquid explosive bin 35 is completely extruded, the explosion pressing head 341 is in contact with the left end face of the second piston 32, the generated pressure shears the second shear pin 344, at this time, the explosion pressing head 341 carries the explosion starting bullet 343 under the action of the pressure and moves leftwards along the large central hole of the first piston 31 until the explosion starting bullet 343 collides with the detonation firing pin 342, the explosion starting bullet 343 is exploded, and the liquid explosive reserved in the liquid explosive injection channel and the perforation section is used as a booster explosive to detonate the liquid explosive injected into the stratum.
The perforation section elastic sealing unit 6 comprises a first elastic sealing ring 61, a supporting sleeve 62 and a second elastic sealing ring 63; the first elastic sealing ring 61, the supporting sleeve 62 and the second elastic sealing ring 63 are sleeved outside the central steel column 5 in sequence from left to right; the first compression ring 7 is located between the first elastic sealing ring 61 and the supporting sleeve 62.
Further, still include second clamping ring 8, second clamping ring 8 cover is established outside center steel column 5 and is located between the right-hand member face of steel column piston and first elastic sealing washer 61, like this, the pressure that the steel column piston applyed is evenly applied to first elastic sealing washer 61 through second clamping ring 8 for the axial compression of first elastic sealing washer 61 is more stable.
The cylinder barrel 2 is fixedly connected with the central steel column 5 through the middle connector 22; the steel column piston penetrates the intermediate joint 22.
Specifically, 4 to 12 process through holes are uniformly distributed on the middle connector 22 along the axial ring shape, and 4 to 12 steel column pistons penetrate through the middle connector 22 and are propped against the left end face of the second compression ring 8; the middle connector 22 is a core component for connecting and fixing the cylinder barrel 2 and the central steel column 5, the internal thread at the right end of the cylinder barrel 2 is fixedly connected with the external thread at the left end of the middle connector 22, and the internal thread of the middle connector 22 is fixedly connected with the external thread at the left end of the central steel column 5. The steel column piston is positioned between the second piston 32 and the second compression ring 8 and penetrates through 4 to 12 process holes arranged on the middle connector 22; the left end of the steel column piston is propped against the right end face of the second piston 32, and the right ends of all (4-12) steel column pistons are propped against the left end face of the second compression ring 8.
Further, the device also comprises a guide head 9, wherein the guide head 9 is sleeved at the right end of the central steel column 5.
The cylinder 2 is provided with a safety hole 21 and the second upper connector 106 is also provided with a safety hole, so that if the pressure in the cylinder 2 exceeds the safety range, the pressure is relieved through the safety hole 21.
The working process of the automatic starting sequence of each unit of the embodiment of the invention is as follows:
(1) Actuation of the drive unit 1:
The first liquid explosive bin 35 is pre-filled with liquid explosive, a high-pressure pump is connected with a second upper connector 106 arranged at the left end of the cylinder barrel 2 through a pipeline, the high-pressure explosive is conveyed to a target position of the well casing 10, namely a target perforation section, pressure liquid is injected into the liquid bin 107 through the high-pressure pump in a pressurizing mode, at the moment, the pressure liquid generates driving pressure F, and a liquid explosive injection channel is in a disconnected state; at this time, the driving unit 1 is started, that is, the present invention is turned on.
(2) The sealing process of the perforation section is started:
After the driving unit 1 of the invention is started, the liquid explosive injection channel is in a disconnected state, so that the perforation section elastic sealing unit 6 for sealing the target perforation section is preferentially and automatically started under the action of the driving pressure F.
As the driving pressure F of the driving unit 1 increases, the pressure to the first piston 31 increases, and after exceeding the upper limit of the load of the fourth shear pin 312, the fourth shear pin 312 is sheared, the first piston 31 moves rightward, and the driving pressure F is transmitted to the second piston 32 by the liquid explosive in the cylinder 2; after the pressure transferred to the second piston 32 exceeds the load of the first shear pin 52, the first shear pin 52 is sheared, the second piston 32 moves rightwards, transferring the pressure to the steel column piston, the steel column piston transfers the pressure to the second compression ring 8 through the intermediate connector 22, the second compression ring 8 transfers the pressure to the first elastic sealing ring 61, the first elastic sealing ring 61 transfers the pressure to the first compression ring 7, the first compression ring 7 transfers the pressure to the second elastic sealing ring 63 through the support sleeve 62, and the second elastic sealing ring 63 transfers the pressure to the guide head 9.
In the transmission process of the pressure, the driving pressure F continuously rises to enable the first piston 31, the second piston 32, the first elastic sealing ring 61, the supporting sleeve 62 and the second elastic sealing ring 63 to displace rightwards, meanwhile, the two sides of the first elastic sealing ring 61 and the second elastic sealing ring 63 are extruded by axial high pressure, the axial width of the first elastic sealing ring 61 and the axial width of the second elastic sealing ring 63 are reduced, and the first elastic sealing ring 61 and the second elastic sealing ring 63 expand radially until being tightly extruded to the inner wall of the well casing 10, so that high-pressure resistant sealing of two ends of a perforation section is realized; when the axial compression deformation of the first elastic sealing ring 61 and the second elastic sealing ring 63 reaches the deformation amount required by the design, that is, the sealing pressure-resistant level required by the design is ensured, which is a key node from the completion of sealing to the start of injection in the next step.
(3) Automatic start of liquid explosive injection into the formation:
When the axial compression deformation of the first elastic sealing ring 61 and the second elastic sealing ring 63 reaches the deformation amount required by design, under the action of the driving pressure F, the two ends of the first liquid explosive injection pore canal 331 are in butt joint communication with the second liquid explosive injection pore canal 51, and the second liquid explosive injection pore canal 51 is in butt joint communication with the third liquid explosive injection pore canal 71 on the first compression ring 7, so that the integral communication of the liquid explosive injection channel is realized, and the communication of the liquid explosive injection channel, perforation holes and an oil-gas stratum is realized, and at the moment, the liquid explosive starts to be injected into the stratum.
Under the action of the driving pressure F, the first piston 31 moves rightward, and the liquid explosive in the first liquid explosive chamber 35 is gradually injected into the stratum through the communicated liquid explosive injection passage.
(4) Automatic starting of the instant pressure explosion, explosion propagation and explosion fracturing process:
Under the continuous action of the driving pressure F, the liquid explosive in the first liquid explosive bin 35 is completely extruded, and at the moment of maintaining the injection pressure, the explosion head 341 impacts the left end face of the second piston 32 to shear the second shear pin 344, at this time, the explosion head 341 carries the explosion initiating bomb 343 under the pressure action, moves leftwards along the large central hole of the first piston 31, the explosion initiating striker 342 collides with the explosion initiating bomb 343, the explosion initiating bomb 343 is exploded, the liquid explosive reserved in the liquid explosive injection channel and the perforating section serves as a booster explosive, and the liquid explosive injected into the oil-gas formation is detonated, so that the explosion fracturing in the formation is realized.
Because the liquid explosive remained in the well casing 10 of the sealed perforation section is detonated and then is attached to the explosive in the stratum outside the well casing 10, the impact force generated after the detonation can be mutually offset, and the impact on the well casing 10 is reduced; the injection is completed, instant detonation of injection pressure is maintained, and the mixing of liquid explosive in the stratum with water and oil and the loss of the liquid explosive in the stratum can be effectively reduced, so that the liquid explosive injected into the stratum can be fully detonated, and the problem that a considerable amount of explosive or explosive mixture remains in the stratum because the liquid explosive cannot be fully detonated is solved.
The liquid explosive is injected into perforation holes and stratum cracks around the perforation holes by taking the shaft as the shaft center, after explosion, a detonation area with the diameter of 10-30 meters can be generated, and the explosion stress wave can extend for 30-60 meters, so that the invention can generate a netlike crack area in the range of about 30-60 meters around the shaft, and the volume fracturing effect is achieved.
Example 3
The embodiment 3 of the invention provides a liquid explosive injection and detonation device for oil and gas reservoir explosion fracturing, which comprises a driving unit 1, a cylinder barrel 2, a liquid explosive injection and detonation unit 3, a driving pressure transmission unit 4, a central steel column 5, a perforation section elastic sealing unit 6 and a first compression ring 7, as shown in fig. 5; the driving unit 1 is positioned in the left end of the cylinder barrel 2; the cylinder barrel 2 is fixedly connected with the central steel column 5; the liquid explosive injection and explosion starting unit 3 is positioned in the cylinder barrel 2; the perforation section elastic sealing units 6 and the first compression rings 7 are sleeved outside the central steel column 5; the driving pressure transmission unit 4 is positioned between the liquid explosive injection and explosion starting unit 3 and the first compression ring 7 and penetrates through the joint of the cylinder barrel 2 and the central steel column 5.
The driving unit 1 is used for generating pressure to push the liquid explosive injection and detonation unit 3 to move rightwards, and the pressure is applied to the perforation section elastic sealing unit 6 through the driving pressure transmission unit 4 in the process of moving the liquid explosive injection and detonation unit 3; after the perforation section elastic sealing unit 6 is compressed, the first compression ring 7 moves rightwards along the central steel column 5 while being subjected to pressure until the axial compression of the perforation section elastic sealing unit 6 reaches the upper limit, the first compression ring 7 stops moving, at this time, the liquid explosive in the liquid explosive injection and detonation unit 3 is injected into the stratum through the liquid explosive injection channel, and after the injection is completed, the liquid explosive is detonated.
The driving unit 1 comprises a first upper connector 101 and an ignition head 103; the first upper connector 101 is positioned at the left end of the cylinder barrel 2 and forms a propellant chamber 104 with the first piston 31; one end of the ignition head 103 penetrates through the first upper connector 101 and is arranged in the propellant bin 104, and the other end of the ignition head is connected with an ignition mechanism positioned outside the cylinder barrel 2 through a cable 102.
The first upper joint 101 is provided with a safety hole, and when the pressure exceeds a safety range, the pressure is relieved through the safety hole.
The liquid explosive injection and explosion starting unit 3 comprises a first piston 31, a second piston 32, a hollow steel column 33 and an explosion starting assembly 34; the first piston 31 and the second piston 32 are movably arranged in the cylinder barrel 2 in sequence from left to right, and a first liquid explosive bin 35 is formed between the first piston and the second piston; the left end of the hollow steel column 33 is positioned on the second piston 32 and is communicated with the first liquid explosive bin 35 through the second piston 32; the right end of the hollow steel column 33 extends into the central steel column 5 and is fixed with the central steel column 5by a first shear pin 52; the initiation assembly 34 is disposed within the first piston 31 and within the first liquid explosive cartridge 35.
The explosion initiating assembly 34 comprises an explosion pressing head 341, an explosion initiating striker 342, an explosion initiating bullet 343 and a second shear pin 344; the explosion head 341 is fixed on the first piston 31 through a second shear pin 344; the detonation striker 342 is positioned on the left end face of the explosion head 341; the explosion proof bullet 343 is arranged at the left side of the explosion head 341.
Specifically, the right end of the first piston 31 is provided with a large central hole for mounting the explosion initiating mechanism 34, and the left end is provided with a small central hole for mounting the detonation striker 342. The right end of the second piston 32 is provided with a large central hole for installing the hollow steel column 33, and the left end is provided with a small central hole, and the large central hole is communicated with the small central hole. The left end of the hollow steel column 33 is arranged in a large central hole at the right end of the second piston 32 and is fixedly connected with the second piston by threads; the central hole of the hollow steel column 33 is coaxially arranged with the central hole of the second piston 32, has the same aperture as the small central hole arranged at the left end of the second piston 32, is mutually communicated and is communicated with the first liquid explosive bin 35; the right end of the hollow steel column 33 extends into the central hole of the central steel column 5; the explosion initiating mechanism 34 is coaxially arranged in a large central hole at the right end of the first piston 31, and the explosion pressing head 341 of the explosion initiating mechanism 34 extends out of the right end face of the first piston 31 and is positioned in the left end of the first liquid explosive bin 35.
The explosion head 341 is fixed on the first piston 31 through a second shear pin 344; the detonation hammer 342 is arranged in a small central hole at the left end of the first piston 31 and is positioned at the left side of the detonation mechanism 34; the explosion proof bullet 343 is disposed at the left end of the central hole of the explosion head 341.
A T-shaped first liquid explosive injection hole 331 is arranged in the hollow steel column 33; the central steel column 5, the first compression ring 7 and the first liquid explosive injection hole 331 are respectively provided with a second liquid explosive injection hole 51 and a third liquid explosive injection hole 71.
Before the liquid explosive is injected, the first liquid explosive injection hole 331, the second liquid explosive injection hole 51, and the third liquid explosive injection hole 71 are not communicated, and finally, the first liquid explosive injection hole 331, the second liquid explosive injection hole 51, and the third liquid explosive injection hole 71 are communicated to form a liquid explosive injection channel under the action of the driving unit 1 as a power source, and then, the first liquid explosive bin 35 is injected into the stratum through the liquid explosive injection channel under the pressure of the first piston 31.
The left end of the hollow steel column 33 is coaxially arranged in the central inner hole of the right end of the second piston 32 and is fixedly connected with threads; the right end of the hollow steel column 33 is coaxially arranged in the central inner hole of the central steel column 5; the hollow steel column 33 and the central steel column 5 are fixed by a first shear pin 52.
The first shear pin 52 serves to prevent the hollow steel column 33 from reciprocating within the central steel column 5 before shipping or starting operation, thereby preventing the second piston 32 from reciprocating within the cylinder 2.
The first liquid explosive bin 35 is filled with liquid explosive in advance, and when the driving unit 1 pushes the first piston 31 to move rightwards; the first piston 31 generates pressure on the liquid explosive and pushes the second piston 32 to move rightwards; the second piston 32 applies pressure to the first elastic sealing ring 61 through the steel column piston; the first elastic sealing ring 61 applies pressure to the first compression ring 7 while being axially compressed by the pressure; the first compression ring 7 moves rightwards after being pressed, and pushes the supporting sleeve 62 to move rightwards; the support sleeve 62 in turn applies pressure to the second elastic sealing ring 63; the second elastic sealing ring 63 is compressed axially after being pressed, and the first compression ring 7 is displaced rightward by the difference between the axial compression of the first elastic sealing ring 61 and the second elastic sealing ring 63 and the displacement generated rightward, and is matched with the hollow steel column 33 to form a liquid explosive injection channel, so that the liquid explosive in the first liquid explosive bin 35 is injected into the stratum; after the injection of the liquid explosive in the first liquid explosive bin 35 is completed; the initiation mechanism 34 initiates detonation of the liquid explosive.
The first elastic sealing ring 61 and the second elastic sealing ring 63 are compressed and then expand in the radial direction, thus a perforation section is formed between the first elastic sealing ring and the well casing 10, and after entering the perforation section through the liquid explosive injection channel, the liquid explosive is injected into the stratum through a plurality of perforation holes on the well casing 10 at high pressure.
When the first piston 31 moves rightwards and simultaneously drives the explosion pressing head 341 to move rightwards, and when the liquid explosive in the first liquid explosive bin 35 is completely extruded, the explosion pressing head 341 is in contact with the left end face of the second piston 32, the generated pressure shears the second shear pin 344, at this time, the explosion pressing head 341 carries the explosion starting bullet 343 under the action of the pressure and moves leftwards along the large central hole of the first piston 31 until the explosion starting bullet 343 collides with the detonation firing pin 342, the explosion starting bullet 343 is exploded, and the liquid explosive reserved in the liquid explosive injection channel and the perforation section is used as a booster explosive to detonate the liquid explosive injected into the stratum.
The perforation section elastic sealing unit 6 comprises a first elastic sealing ring 61, a supporting sleeve 62 and a second elastic sealing ring 63; the first elastic sealing ring 61, the supporting sleeve 62 and the second elastic sealing ring 63 are sleeved outside the central steel column 5 in sequence from left to right; the first compression ring 7 is located between the first elastic sealing ring 61 and the supporting sleeve 62.
Further, a second press ring 8 is also included; the second compression ring 8 is sleeved outside the central steel column 5 and is located between the right end face of the steel column piston and the first elastic sealing ring 61, so that the pressure applied by the steel column piston is uniformly applied to the first elastic sealing ring 61 through the second compression ring 8, and the axial compression of the first elastic sealing ring 61 is more stable.
The cylinder barrel 2 is fixedly connected with the central steel column 5 through the middle connector 22; the steel column piston penetrates the intermediate joint 22.
Specifically, 4 to 12 process through holes are uniformly distributed on the middle connector 22 along the axial ring shape, and 4 to 12 steel column pistons penetrate through the middle connector 22 and are propped against the left end face of the second compression ring 8; the middle connector 22 is a core component for connecting and fixing the cylinder barrel 2 and the central steel column 5, the internal thread at the right end of the cylinder barrel 2 is fixedly connected with the external thread at the left end of the middle connector 22, and the internal thread of the middle connector 22 is fixedly connected with the external thread at the left end of the central steel column 5. The steel column piston is positioned between the second piston 32 and the second compression ring 8 and penetrates through 4 to 12 process holes arranged on the middle connector 22; the left end of the steel column piston is propped against the right end face of the second piston 32, and the right ends of all (4-12) steel column pistons are propped against the left end face of the second compression ring 8.
Further, a guide head 9 is included; the guide head 9 is sleeved at the right end of the central steel column 5.
The cylinder 2 is provided with a safety hole 21 and the second upper connector 106 is also provided with a safety hole, so that if the pressure in the cylinder 2 exceeds the safety range, the pressure is relieved through the safety hole 21.
The working process of the automatic starting sequence of each unit of the embodiment of the invention is as follows:
(1) Actuation of the drive unit 1:
The first liquid explosive bin 35 is preset with liquid explosive, the invention is conveyed to a target position of the shaft sleeve 10, namely a target perforation section, and the ignition mechanism ignites the ignition head 103 through the cable 102; the ignition head 103 ignites the propellant in the propellant cartridge 104, the propellant burns and generates a driving pressure F, and the liquid explosive injection channel is in an off state; at this time, the driving unit 1 is started, that is, the present invention is turned on.
(2) Sealing process of perforation section:
After the driving unit 1 of the invention is started, the liquid explosive injection channel is in a disconnected state, so that the perforation section elastic sealing unit 6 for sealing the target perforation section is preferentially and automatically started under the action of the driving pressure F.
As the driving pressure F of the driving unit 1 increases, the pressure to the first piston 31 increases, and after exceeding the upper limit of the load of the fourth shear pin 312, the fourth shear pin 312 is sheared, the first piston 31 moves rightward, and the driving pressure F is transmitted to the second piston 32 by the liquid explosive in the cylinder 2; after the pressure transferred to the second piston 32 exceeds the load of the first shear pin 52, the first shear pin 52 is sheared, the second piston 32 moves rightwards, transferring the pressure to the steel column piston, the steel column piston transfers the pressure to the second compression ring 8 through the intermediate connector 22, the second compression ring 8 transfers the pressure to the first elastic sealing ring 61, the first elastic sealing ring 61 transfers the pressure to the first compression ring 7, the first compression ring 7 transfers the pressure to the second elastic sealing ring 63 through the support sleeve 62, and the second elastic sealing ring 63 transfers the pressure to the guide head 9.
In the transmission process of the pressure, the driving pressure F continuously rises to enable the first piston 31, the second piston 32, the first elastic sealing ring 61, the supporting sleeve 62 and the second elastic sealing ring 63 to displace rightwards, meanwhile, the two sides of the first elastic sealing ring 61 and the second elastic sealing ring 63 are extruded by axial high pressure, the axial width of the first elastic sealing ring 61 and the axial width of the second elastic sealing ring 63 are reduced, and the first elastic sealing ring 61 and the second elastic sealing ring 63 expand radially until being tightly extruded to the inner wall of the well casing 10, so that high-pressure resistant sealing of two ends of a perforation section is realized; when the axial compression deformation of the first elastic sealing ring 61 and the second elastic sealing ring 63 reaches the deformation amount required by the design, that is, the sealing pressure-resistant level required by the design is ensured, which is a key node from the completion of sealing to the start of injection in the next step.
(3) Automatic start of liquid explosive injection into the formation:
When the axial compression deformation of the first elastic sealing ring 61 and the second elastic sealing ring 63 reaches the deformation amount required by design, under the action of the driving pressure F, the two ends of the first liquid explosive injection pore canal 331 are in butt joint communication with the second liquid explosive injection pore canal 51, and the second liquid explosive injection pore canal 51 is in butt joint communication with the third liquid explosive injection pore canal 71 on the first compression ring 7, so that the integral communication of the liquid explosive injection channel is realized, and the communication of the liquid explosive injection channel, perforation holes and an oil-gas stratum is realized, and at the moment, the liquid explosive starts to be injected into the stratum.
Under the action of the driving pressure F, the first piston 31 moves rightward, and the liquid explosive in the first liquid explosive chamber 35 is gradually injected into the stratum through the communicated liquid explosive injection passage.
(4) Automatic starting of the instant pressure explosion, explosion propagation and explosion fracturing process:
Under the continuous action of the driving pressure F, the liquid explosive in the first liquid explosive bin 35 is completely extruded, and at the moment of maintaining the injection pressure, the explosion head 341 impacts the left end face of the second piston 32 to shear the second shear pin 344, at this time, the explosion head 341 carries the explosion initiating bomb 343 under the pressure action, moves leftwards along the large central hole of the first piston 31, the explosion initiating striker 342 collides with the explosion initiating bomb 343, the explosion initiating bomb 343 is exploded, the liquid explosive reserved in the liquid explosive injection channel and the perforating section serves as a booster explosive, and the liquid explosive injected into the oil-gas formation is detonated, so that the explosion fracturing in the formation is realized.
Because the explosive remained in the well casing 10 of the sealed perforation section is detonated and then attached to the explosive in the stratum outside the well casing 10, the impact force generated after the detonation can be mutually offset, and the impact on the well casing 10 is reduced; the injection is completed, instant detonation of injection pressure is maintained, and the mixing of liquid explosive in the stratum with water and oil and the loss of the liquid explosive in the stratum can be effectively reduced, so that the liquid explosive injected into the stratum can be fully detonated, and the problem that a considerable amount of explosive or explosive mixture remains in the stratum because the liquid explosive cannot be fully detonated is solved.
The liquid explosive is injected into perforation holes and stratum cracks around the perforation holes by taking the shaft as the shaft center, after explosion, a detonation area with the diameter of 10-30 meters can be generated, and the explosion stress wave can extend for 30-60 meters, so that the invention can generate a netlike crack area in the range of about 30-60 meters around the shaft, and the volume fracturing effect is achieved.
The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention.