Fracturing sliding sleeve for production tracing

Abstract

The invention relates to the technical field of oil and gas yield increase, in particular to a fracturing sliding sleeve for production tracing, and aims to solve the technical problem that a tracing effect cannot be achieved in the production process due to the fact that a tracing material is exposed in a construction channel and is easy to scour away in the prior art. The fracturing sliding sleeve for production tracing comprises a tracing mechanism, and the tracing mechanism comprises an upper connector, a central pipe and a communicating sleeve. And the communicating sleeve is sleeved on the central pipe and is inserted into the upper joint. The central pipe is provided with an overflowing channel and an overflowing hole, and the communicating sleeve is provided with a production channel. The upper connector is provided with a liquid inlet hole. According to the fracturing sliding sleeve for production tracing, the tracer agent is arranged in the production channel which can be switched between connection and disconnection with the liquid inlet hole and the overflowing hole, and the production channel and the overflowing channel are communicated with each other in cooperation with sliding of the communicating sleeve. The technical problem that in an existing fracturing sliding sleeve for production tracing, a tracing material is exposed in a construction channel and is prone to being washed away, and therefore the tracing effect cannot be achieved in the production process is solved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas production enhancement technology, and in particular to a fracturing sleeve for production tracing. Background Technology

[0002] After oil and gas well stimulation, tracer materials and stimulation fluids are typically injected into the stimulated formation to monitor production status. These tracer materials are brought back to the surface with the oil and gas, and the production status of each formation is assessed by analyzing the proportions of different types of tracer materials. However, the tracer materials are affected by fracturing sand plugging and oil and gas return from reservoir fractures, leading to reduced accuracy in production monitoring. Attaching the tracer material to the production channel of the fracturing sleeve is the best way to monitor that formation. However, the production channel of the conventionally activated sleeve also serves as the construction channel during operation, making it easy for the attached tracer material to be washed away and rendered ineffective in production.

[0003] Existing fracturing sleeves for production tracing have a technical problem: the tracing material is easily washed away when exposed in the construction channel, thus failing to achieve the tracing effect during the production process. Summary of the Invention

[0004] The purpose of this invention is to provide a fracturing sleeve for production tracing, so as to solve the technical problem in the related art that the tracing material is easily washed away when exposed in the construction channel, thus failing to play a tracing role in the production process.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] The fracturing sleeve for production tracing provided by this invention includes:

[0007] A tracer mechanism includes an upper connector, a central tube, and a connecting sleeve. The connecting sleeve is fitted onto the central tube and inserted into the upper connector. The central tube has a flow channel and a flow hole on its side wall communicating with the flow channel. The connecting sleeve has a production channel for containing tracer. The upper connector has a liquid inlet on its side wall. The connecting sleeve can slide along its own axis to switch both the liquid inlet and the flow hole from a closed state to a connected state with the production channel.

[0008] Specifically, the diversion tube string includes an upper connector and a central tube. The connecting sleeve is fitted onto the central tube and inserted into the upper connector. The inner hole of the central tube is configured as a flow channel, and a flow hole is formed in the side wall of the central tube. The upper connector has an inlet hole. Initially, the inlet hole, the production channel, and the flow hole are not connected. The connecting sleeve can slide along the central tube away from the upper connector to connect the inlet hole, the production channel, the flow hole, and the flow channel.

[0009] Specifically, it also includes a delayed unlocking mechanism, which comprises a closing sleeve and a fixing pin. The closing sleeve is installed on the connecting sleeve and fitted onto the central tube. The closing sleeve is locked to the central tube by the fixing pin to restrict the axial position of the connecting sleeve, thereby maintaining a closed state between the liquid inlet, the production channel, and the flow outlet. The fixing pin is made of a soluble material.

[0010] Specifically, the delayed unlocking mechanism further includes a retaining ring and a spring. The retaining ring is sleeved on the central tube and inserted into the closing sleeve. The two ends of the spring abut against the closing sleeve and the retaining ring respectively to apply a pushing force to the closing sleeve, thereby causing the connecting sleeve to slide away from the upper connector.

[0011] Specifically, the delayed unlocking mechanism further includes a retaining ring, and the retaining ring has a groove on its outer periphery. The retaining ring is an elastic element, and its free outer diameter is larger than its outer diameter. The retaining ring engages with the groove and abuts against the inner wall of the closing sleeve. The inner wall of the closing sleeve has a positioning groove, which is located between the connecting sleeve and the retaining ring. The closing sleeve can slide away from the upper connector to allow the retaining ring to engage with the positioning groove.

[0012] Specifically, it also includes a fracturing start-up mechanism, which includes a start-up sliding sleeve. The start-up sliding sleeve is fitted onto both the central tube and the closing sleeve. The central tube also has a pressure relief hole. In the initial state, the start-up sliding sleeve isolates the pressure relief hole and the fixing pin from the formation. The start-up sliding sleeve can slide along the axial direction of the central tube to release the isolation between the pressure relief hole and the fixing pin and the formation.

[0013] Specifically, the fracturing initiation mechanism further includes a retaining ring and an initiation shear pin. The retaining ring is located at the end of the initiation sliding sleeve furthest from the closing sleeve and is fitted onto the central tube. When the pressure on the initiation sliding sleeve does not exceed a threshold, it is locked to the retaining ring by the initiation shear pin. When the pressure exceeds the threshold, the initiation shear pin is sheared, thereby disengaging the initiation sliding sleeve from the closing sleeve.

[0014] Specifically, the starting sleeve, the central tube, and the closing sleeve form a first pressure chamber. The pressure relief hole communicates with the first pressure chamber. The pressure in the first pressure chamber is used to apply a thrust to the starting sleeve. When the pressure on the starting sleeve exceeds a threshold, the starting shear pin is sheared, and the starting sleeve disengages from the locked state.

[0015] Specifically, the central tube also has a balance hole. The starting sleeve, the central tube, and the fixing ring form a second pressure chamber. The balance hole communicates with the second pressure chamber. The pressure difference between the first pressure chamber and the second pressure chamber is used to apply a thrust to the starting sleeve. When the pressure on the starting sleeve exceeds a threshold, the starting shear pin is sheared, and the starting sleeve disengages from the locked state.

[0016] Specifically, the fracturing initiation mechanism further includes a ball seat and a construction ball. The ball seat is connected to the inner wall of the central tube and located between the pressure relief hole and the balance hole. When the construction ball is seated on the ball seat, the pressure in the first pressure chamber increases, and the pressure in the first pressure chamber is greater than the pressure in the second pressure chamber. The pressure difference between the first and second pressure chambers applies a thrust to the initiation sliding sleeve, causing the initiation sliding sleeve to shear the initiation shear pin and abut against the fixing ring, thereby exposing the pressure relief hole and the fixing pin in the formation.

[0017] Specifically, the construction ball is made of a soluble material.

[0018] Based on the above technical solutions, the beneficial effects of the present invention are analyzed as follows:

[0019] This invention provides a fracturing sleeve for production tracing, comprising:

[0020] A tracer mechanism includes an upper connector, a central tube, and a connecting sleeve. The connecting sleeve is fitted onto the central tube and inserted into the upper connector. The central tube has a flow channel and a flow hole on its side wall communicating with the flow channel. The connecting sleeve has a production channel for containing tracer. The upper connector has a liquid inlet on its side wall. The connecting sleeve can slide along its own axis to switch both the liquid inlet and the flow hole from a closed state to a connected state with the production channel.

[0021] In practical applications, a fracturing sleeve for production tracers and tools such as packers are connected to the drilling string and lowered into the well. After reaching the predetermined position, the packer is first set, sealing the reservoir above and below the fracturing sleeve. During the fracturing process, the flow channel is used as the drilling channel to perform fracturing operations on the formation. At this time, since the production channel and the flow channel are not connected, the tracer in the production channel remains intact. After the fracturing operation is completed, the production process begins. The connecting sleeve slides along the axis of the shunt string to sequentially connect the formation, the inlet, the production channel, the flow orifice, and the flow channel. At this time, since the upper and lower ends of the corresponding layer of the sliding sleeve are sealed by packers, the inlet hole becomes the only channel in the production process. During the production process, the downhole oil and gas enter through the inlet hole. Through the tracer attached to the connecting sleeve, the oil and gas mix together with the tracer and enter the flow channel through the production channel and the flow hole, finally reaching the wellhead. At the wellhead, by analyzing the ratio of different types of tracer materials, the production of each layer is finally determined.

[0022] As can be seen, compared with the prior art, this fracturing sleeve for production tracer overcomes the technical problem of existing fracturing sleeves for production tracer, which have the tracer material exposed in the construction channel and thus easily washed away, preventing it from playing a tracer role in the production process. This is achieved by placing the tracer in the production channel, which can switch between open and closed states with the inlet and the flow channel, and then using the sliding of the connecting sleeve along its own axis to control the connection state between the tracer and the flow channel. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the initial state of the fracturing sleeve for production tracing provided in an embodiment of the present invention;

[0025] Figure 2 for Figure 1 An enlarged schematic diagram of the tracer mechanism in the diagram;

[0026] Figure 3 for Figure 1 Enlarged schematic diagram of the delayed unlocking mechanism in the middle;

[0027] Figure 4 for Figure 1 A magnified schematic diagram of the structure at the fracturing start-up mechanism in the middle;

[0028] Figure 5 A schematic diagram of the structure of the fracturing sleeve used for production tracing during fracturing operations;

[0029] Figure 6 This is a schematic diagram of the structure of the fracturing sleeve used for oil and gas production as a production tracer.

[0030] icon:

[0031] 100. Tracer mechanism; 110. Upper connector; 103. Liquid inlet; 120. Central tube; 101. Flow channel; 102. Flow hole; 105. Pressure relief hole; 106. Balance hole; 130. Connecting sleeve; 104. Production channel; 131. Tracer;

[0032] 200. Delayed unlocking mechanism; 210. Closing sleeve; 202. Positioning groove; 220. Fixing pin; 230. Retaining ring; 201. Groove; 240. Spring; 250. Snap ring;

[0033] 300, fracturing start mechanism; 310, starter sleeve; 301, first pressure chamber; 302, second pressure chamber; 320, fixing ring; 330, starter shear pin; 340, ball seat; 350, construction ball. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0036] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0037] Existing fracturing sleeves for production tracing have a technical problem: the tracing material is easily washed away when exposed in the construction channel, thus failing to achieve the tracing effect during the production process.

[0038] In view of this, the present invention provides a fracturing sleeve for production of tracers, comprising:

[0039] A tracer mechanism 100 includes an upper connector 110, a central tube 120, and a connecting sleeve 130. The connecting sleeve 130 is fitted onto the central tube 120 and inserted into the upper connector 110. The central tube 120 is provided with a flow channel 101 and a flow hole 102 located on the side wall of the central tube 120 and communicating with the flow channel 101. The connecting sleeve 130 is provided with a production channel 104 for accommodating tracer 131. The upper connector 110 has a liquid inlet 103 on its side wall. The connecting sleeve 130 can slide along its own axis to switch both the liquid inlet 103 and the flow hole 102 from a closed state to a connected state with the production channel 104.

[0040] In summary, the fracturing sleeve for production tracing provided by this invention can achieve the following technical effects:

[0041] This fracturing sleeve for production tracking places the tracer 131 in a production channel 104 that can switch between open and closed states with the inlet 103 and the outlet 102. A connecting sleeve 130 slides along its own axis to control the connection between the tracer 131 and the outlet channel 101. This overcomes the technical problem of existing fracturing sleeves for production tracking where the tracer material is exposed in the construction channel and easily washed away, thus failing to provide a tracking effect during production.

[0042] The following combination Figures 1 to 6 The structure and shape of the fracturing sleeve for production tracing provided in this embodiment are described in detail below:

[0043] Specifically, regarding how the fracturing sleeve used for production tracking switches from fracturing operation mode to oil and gas production mode:

[0044] The fracturing sleeve for production tracking also includes a delayed unlocking mechanism 200, which includes a closing sleeve 210 and a fixing pin 220. The closing sleeve 210 is installed on the connecting sleeve 130 and sleeved on the central tube 120. The closing sleeve 210 is locked to the central tube 120 by the fixing pin 220 to restrict the axial position of the connecting sleeve 130, thereby keeping the inlet hole 103, production channel 104 and flow hole 102 in a closed state. The fixing pin 220 is made of a soluble material. The fixing pin 220 will begin to dissolve after contacting the fluid in the well. When the fixing pin 220 is dissolved, the closing sleeve 210 is released from the locked state, so that the connecting sleeve 130 can slide along the axial direction of the central tube 120, thereby switching the production channel 104, inlet hole 103 and flow hole 102 from the closed state to the open state. The closing sleeve 210 and the connecting sleeve 130 are relatively stationary, and the connection method between the closing sleeve 210 and the connecting sleeve 130 can be set as a threaded connection or a snap-fit ​​connection. The soluble material of the fixing pin 220 is used to control the time from the start of dissolution to the closing sleeve 210 disengaging from the locked state, i.e., the delayed opening time.

[0045] Regarding how the closing sleeve 210 causes the connecting sleeve 130 to slide axially along the central tube 120 after the fixing pin 220 is dissolved, specifically:

[0046] The delayed unlocking mechanism 200 also includes a retaining ring 230 and a spring 240. The retaining ring 230 is sleeved on the central tube 120 and inserted into the closing sleeve 210. The two ends of the spring 240 abut against the closing sleeve 210 and the retaining ring 230 respectively to apply a pushing force to the closing sleeve 210, thereby driving the connecting sleeve 130 to slide away from the upper connector 110. The upper connector 110, the retaining ring 230 and the central tube 120 are fixed as one piece, and the connection method between the upper connector 110, the retaining ring 230 and the central tube 120 can be set as a threaded connection or a snap-fit ​​connection.

[0047] Regarding how the production channel 104, the liquid inlet 103, and the flow outlet 102 are precisely aligned, specifically:

[0048] The delayed unlocking mechanism 200 also includes a retaining ring 250, and a groove 201 is formed on the outer periphery of the retaining ring 230. The retaining ring 250 is an elastic element, and the free outer diameter of the retaining ring 250 is larger than the outer diameter of the retaining ring 250. The retaining ring 250 engages with the groove 201 and abuts against the inner wall of the closing sleeve 210. A positioning groove 202 is formed on the inner wall of the closing sleeve 210, and the positioning groove 202 is located between the connecting sleeve 130 and the retaining ring 230. The closing sleeve 210 can slide away from the upper connector 110 so that the retaining ring 250 engages with the positioning groove 202, thereby terminating the sliding of the closing sleeve 210 and realizing the control of the sliding distance of the closing sleeve 210. At this time, the liquid inlet hole 103 and the flow hole 102 are aligned with and connected to the production channel 104. The retaining ring 250 can be set as a C-shaped ring.

[0049] Specifically, regarding how the production tracer fracturing sleeve switches from the initial wellhead entry state to the fracturing operation state:

[0050] The fracturing sleeve for production tracking also includes a fracturing initiation mechanism 300, which includes an initiation sleeve 310. The initiation sleeve 310 is fitted onto both the central tube 120 and the closing sleeve 210. The central tube 120 also has a pressure relief hole 105. Initially, the initiation sleeve 310 isolates the pressure relief hole 105 and the fixing pin 220 from the formation. The initiation sleeve 310 can slide along the axial direction of the central tube 120 to release the isolation between the pressure relief hole 105 and the fixing pin 220 and the formation. The pressure relief hole 105 communicates with the formation, and fracturing operations are performed through the pressure relief hole 105. Simultaneously, the previously sealed fixing pin 220 is exposed to the fluid in the well and begins to dissolve.

[0051] Regarding how the fracturing sleeve used for production tracking is maintained in its initial state upon entry into the well, specifically:

[0052] In this embodiment, the fracturing initiation mechanism 300 further includes a retaining ring 320 and an initiation shear pin 330. The retaining ring 320 is disposed at the end of the initiation sliding sleeve 310 away from the closing sleeve 210 and is sleeved on the central tube 120. When the pressure on the initiation sliding sleeve 310 does not exceed a threshold, it is locked to the retaining ring 320 by the initiation shear pin 330. When the pressure exceeds the threshold, the initiation shear pin 330 is sheared, thereby disengaging the initiation sliding sleeve 310 from the closing sleeve 210.

[0053] Specifically, regarding how the starting clipper 330 was cut:

[0054] The starting sleeve 310, the central tube 120, and the closing sleeve 210 form a first pressure chamber 301. The pressure relief hole 105 communicates with the first pressure chamber 301. The pressure in the first pressure chamber 301 is used to apply a thrust to the starting sleeve 310. When the pressure on the starting sleeve 310 exceeds a threshold, the starting shear pin 330 is sheared, and the starting sleeve 310 is released from the locked state.

[0055] Specifically, regarding how the fracturing initiation mechanism 300 prevents the initiation shear pin 330 from being sheared off before fracturing operations:

[0056] The central tube 120 also has a balance hole 106. The starting sleeve 310, the central tube 120, and the fixing ring 320 form a second pressure chamber 302. The balance hole 106 communicates with the second pressure chamber 302, and the pressure in the second pressure chamber 302 is used to weaken or counteract the pressure in the first pressure chamber 301; the pressure difference between the first pressure chamber 301 and the second pressure chamber 302 is used to apply a thrust to the starting sleeve 310. When the pressure on the starting sleeve 310 exceeds a threshold, the starting shear pin 330 is sheared, and the starting sleeve 310 is released from the locked state.

[0057] Regarding how the pressure difference between the first pressure chamber 301 and the second pressure chamber 302 is generated, specifically:

[0058] In this embodiment, the fracturing initiation mechanism 300 further includes a ball seat 340 and a construction ball 350. The ball seat 340 is connected to the inner wall of the central tube 120 and is located between the pressure relief hole 105 and the balance hole 106. When the construction ball 350 is seated in the ball seat 340, the flow passage 101 is blocked by the construction ball 350, and the fluid in the formation can only flow to the pressure relief hole 105 and accumulate in the first pressure chamber 301. The pressure in the first pressure chamber 301 increases, and the pressure in the first pressure chamber 301 is greater than the pressure in the second pressure chamber 302. The pressure difference between the first pressure chamber 301 and the second pressure chamber 302 is used to apply a thrust to the initiation sliding sleeve 310, so that the initiation sliding sleeve 310 shears the initiation shear pin 330 and abuts against the fixing ring 320, thereby exposing the pressure relief hole 105 and the fixing pin 220 in the formation. The construction ball 350 is made of a soluble material. When the construction ball 350 is dissolved, the blockage of the ball seat 340 is released, and the flow channel 101 is restored to flow.

[0059] In summary, the specific working process of the fracturing sleeve for production tracing provided in this embodiment is as follows:

[0060] A fracturing sleeve for production tracing, along with tools such as a packer, is connected to the drilling string and lowered into the well. After reaching the predetermined position, the packer is first set. Once the packer is set, it isolates the reservoir corresponding to the fracturing sleeve. When drilling is required at a specific layer, a drilling ball 350 matching the sleeve is dropped. Before the drilling ball 350 lands on the ball seat 340, the forces acting on the starting sleeve 310 through the pressure relief hole 105 and the balance hole 106 are in a balanced state, ensuring that the sleeve will not be affected when drilling other layers. When the working ball 350 falls onto the ball seat 340, the balance here is broken. As the pressure increases, the pressure at the end of the pressure relief hole 105 gradually exceeds the pressure at the end of the balance hole 106. When the pressure difference reaches the starting pressure of the starting shear pin 330, the starting shear pin 330 is cut off, and the starting sliding sleeve 310 moves downward, opening the pressure relief hole 105. Fracturing is then carried out through the pressure relief hole 105. At the same time as the pressure relief hole 105 is opened, the previously sealed fixing pin 220 is exposed to the liquid in the well and begins to dissolve.

[0061] When the fixing pin 220 dissolves to the point where the remaining portion can no longer withstand the rebound force of the spring 240, the spring 240 pushes the closing sleeve 210 downwards. During this downward movement, the closing sleeve 210 causes the connecting sleeve 130 to move as well. When the closing sleeve 210 reaches the starting sliding sleeve 310, it closes the pressure relief hole 105. Simultaneously, the positioning groove 202 on the closing sleeve 210 moves to the retaining ring 250, which returns to its original position, locking the connecting sleeve 130 onto the retaining ring 230. This ensures that the connecting sleeve 130 will not close during production. When the retaining ring 230 is on, the inlet hole 103 is fully open. Since the upper and lower ends of the corresponding layer of the sliding sleeve are sealed by packers, the inlet hole 103 becomes the only channel in the production process. During the production process, the downhole oil and gas enter through the inlet hole 103. Through the tracer 131 attached to the connecting sleeve 130, the oil and gas mix together with the tracer material and enter the flow channel 101 in the tubing through the production channel 104 and the flow hole 102, and finally reach the wellhead. At the wellhead, by analyzing the ratio of different types of tracer materials, the production of each layer is finally determined.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fracturing sleeve for production tracing, characterized in that... ,include: A tracer mechanism includes an upper connector, a central tube, and a connecting sleeve. The connecting sleeve is fitted onto the central tube and inserted into the upper connector. The central tube is provided with a flow channel and a flow hole on the side wall of the central tube communicating with the flow channel. The connecting sleeve is provided with a production channel for containing tracer. The side wall of the upper connector is provided with a liquid inlet. The connecting sleeve can slide along its own axis to switch both the liquid inlet and the flow hole from a closed state to a connected state with the production channel.

2. The fracturing sleeve for production tracing according to claim 1, characterized in that... : It also includes a delayed unlocking mechanism, which includes a closing sleeve and a fixing pin; the closing sleeve is installed on the connecting sleeve and sleeved on the central tube; the closing sleeve is locked to the central tube by the fixing pin to restrict the axial position of the connecting sleeve, thereby keeping the liquid inlet, the production channel and the flow hole in a closed state; the fixing pin is made of a soluble material.

3. The fracturing sleeve for production tracing according to claim 2, characterized in that... : The delayed unlocking mechanism also includes a retaining ring and a spring; the retaining ring is sleeved on the central tube and inserted into the closing sleeve, and the two ends of the spring abut against the closing sleeve and the retaining ring respectively to apply a pushing force to the closing sleeve, thereby driving the connecting sleeve to slide away from the upper connector.

4. The fracturing sleeve for production tracing according to claim 3, characterized in that... : The delayed unlocking mechanism further includes a retaining ring, and the outer periphery of the retaining ring has a groove; the retaining ring is configured as an elastic element, and the free outer diameter of the retaining ring is larger than the outer diameter of the retaining ring; the retaining ring engages with the groove and abuts against the inner wall of the closing sleeve; the inner wall of the closing sleeve has a positioning groove, which is located between the connecting sleeve and the retaining ring; the closing sleeve can slide away from the upper connector so that the retaining ring engages with the positioning groove.

5. The fracturing sleeve for production tracing according to claim 2, characterized in that... : It also includes a fracturing start-up mechanism, which includes a start-up sliding sleeve; the start-up sliding sleeve is simultaneously fitted onto the central tube and the closing sleeve; the central tube also has a pressure relief hole; in the initial state, the start-up sliding sleeve isolates the pressure relief hole and the fixing pin from the formation; the start-up sliding sleeve can slide along the axial direction of the central tube to release the isolation between the pressure relief hole and the fixing pin and the formation.

6. The fracturing sleeve for production tracing according to claim 5, characterized in that... : The fracturing start mechanism further includes a fixing ring and a start shear pin; the fixing ring is located at the end of the start sliding sleeve away from the closing sleeve and is sleeved on the central tube; when the pressure on the start sliding sleeve does not exceed a threshold, it is locked to the fixing ring by the start shear pin; when the pressure exceeds the threshold, the start shear pin is sheared, thereby causing the start sliding sleeve to disengage from the closing sleeve.

7. The fracturing sleeve for production tracing according to claim 6, characterized in that... : The starting sleeve, the central tube, and the closing sleeve form a first pressure chamber; the pressure relief hole communicates with the first pressure chamber; the pressure difference in the first pressure chamber is used to apply a thrust to the starting sleeve; when the pressure on the starting sleeve exceeds a threshold, the starting shear pin is sheared, and the starting sleeve disengages from the locked state.

8. The fracturing sleeve for production tracing according to claim 7, characterized in that... : The central tube also has a balance hole; the starting sleeve, the central tube, and the fixing ring form a second pressure chamber; the balance hole communicates with the second pressure chamber; the pressure difference between the first pressure chamber and the second pressure chamber is used to apply a thrust to the starting sleeve; when the pressure on the starting sleeve exceeds a threshold, the starting shear pin is sheared, and the starting sleeve is released from the locked state.

9. The fracturing sleeve for production tracing according to claim 8, characterized in that... : The fracturing start-up mechanism further includes a ball seat and a construction ball; the ball seat is connected to the inner wall of the central tube and located between the pressure relief hole and the balance hole; when the construction ball is seated on the ball seat, the pressure in the first pressure chamber increases, and the pressure in the first pressure chamber is greater than the pressure in the second pressure chamber. The pressure difference between the first pressure chamber and the second pressure chamber is used to apply a thrust to the start-up sliding sleeve, so as to drive the start-up sliding sleeve to shear the start-up shearing nail and abut against the fixing ring, thereby exposing the pressure relief hole and the fixing nail in the formation.

10. The fracturing sleeve for production tracing according to claim 9, characterized in that... : The construction ball is made of a soluble material.

Images