Simulation ball seat with test function

Abstract

The invention discloses a simulation ball seat with a test function, which comprises a central pipe, the central pipe is in a reducing hollow cylinder shape, one end of the central pipe is provided with a well temperature test module, and the central pipe is sequentially provided with a dissolution test module, a ball seat trafficability test module and a sleeve ovality test module along the direction far away from the well temperature test module. According to the simulation ball seat with the testing function, the functions of well temperature testing, dissolution testing, ball seat trafficability testing and sleeve ovality testing can be integrated, four kinds of testing are achieved through one-time drilling, and real downhole parameters are obtained. Meanwhile, a mechanical structure and a hydraulic control mode are adopted for testing, the mode that the mechanical structure is converted into an electric signal in an existing test is changed, the structure is simplified, and cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of fracturing in the process of oil and natural gas development, and relates to a simulated ball seat with a testing function. Background Art

[0002] For the development of tight oil and gas reservoirs, the bridge plug perforation combined with fracturing technology is currently the most effective method. The core tool of this technology is the soluble bridge plug or soluble ball seat. This tool has the following two requirements: On the one hand, the risks of encountering obstruction and sticking during pumping are difficult to deal with. Before pumping the real bridge plug or ball seat, it is necessary to pre-pump the simulated ball seat to check the wellbore passability and reduce the risk of encountering obstruction and sticking; On the other hand, the design of the soluble ball seat or soluble bridge plug requires accurate understanding of the actual wellbore temperature, the change in the ovality of the inner diameter of the casing, and the dissolution of the soluble material during the pumping process. However, the current actual situation is as follows: ① When pumping conventional simulated soluble ball seats or bridge plugs on site, only the passability of the tool can be checked. Conventional simulated ball seats cannot measure data such as wellbore temperature and casing inner diameter. ② Bridge plug or ball seat perforation operation requires the maximum wellbore temperature and casing deformation data at the setting position. At present, the wellbore temperature and casing deformation can only be measured by tools such as well temperature logging and eight-arm diameter. These tools are all full-wellbore tests, and they need to be drilled separately to convert mechanical signals into electrical signals. The operation time is long and the cost is high. ③ The dissolution performance test of soluble bridge plugs and soluble ball seats can usually only be carried out indoors, which is far from the actual dissolution environment of the ball seat during the pumping process. Therefore, it is urgent to design a low-cost and easy-to-operate test tool that integrates the above test functions and uses mechanical hydraulic control instead of electronic control to facilitate promotion and application. Summary of the invention

[0003] The purpose of the present invention is to provide a simulated ball seat with a testing function, which solves the problem of insufficient research on data such as well temperature measurement, dissolution of soluble materials, ball seat passability, and casing inner diameter.

[0004] The technical solution adopted by the present invention is a simulated ball seat with a testing function, comprising a center tube, which is a hollow cylinder with a variable diameter. A well temperature test module is arranged at one end of the center tube, and a dissolution test module, a ball seat passability test module, and a casing ovality test module are arranged in sequence on the upper edge of the center tube in the direction away from the well temperature test module.

[0005] The present invention is also characterized in that:

[0006] A strip hole is opened at the end of the pipe wall of the central pipe. The well temperature test module comprises a clamp. A retention point thermometer is clamped at the end of the clamp. One end of the clamp holding the retention point thermometer is inserted into the strip hole.

[0007] A sealing ring is arranged at the connection between the clamp and the strip hole.

[0008] The strip holes are filled with shock-absorbing kerosene.

[0009] The dissolution test module includes a first dissolution test ring and a second dissolution test ring. A shoulder is provided on the central tube away from the well temperature test module. The first dissolution test ring and the second dissolution test ring are both sleeved on the central tube, and the end face of the first dissolution test ring is connected to the shoulder.

[0010] The ball seat passability test module comprises a composite material flow test gauge, which is sleeved on the center tube, and the outer wall of the composite material flow test gauge is chamfered at the top and bottom.

[0011] The casing ovality test module includes a plurality of lead well diameter test pins and a sheath. The longitudinal section of the sheath is "L-shaped". The sheath is sleeved on the central tube. A positioning hole is provided on the sheath. The lead well diameter test pin is arranged in the positioning hole. A reducing piston is provided between the sheath and the central tube. The reducing piston is sleeved on the central tube. The outer wall of the reducing piston near the bottom of the well is chamfered. The reducing piston is in sliding contact with the lead well diameter test pin.

[0012] The sheath is provided with a liquid inlet hole, and the liquid inlet hole is located at a position where the positioning hole is far away from the ball seat passability test module;

[0013] A return spring is arranged between the end of the variable diameter piston close to the ball seat passability test module and the sleeve, and the return spring is arranged on the center tube.

[0014] The beneficial effects of the present invention are:

[0015] The present invention provides a simulated ball seat with testing function, which can integrate well temperature test, dissolution test module, ball seat passability test, and casing ovality test functions, realizes four tests in one drilling trip, and obtains real downhole parameters. At the same time, the test is carried out in the form of mechanical structure and hydraulic control, which changes the way of converting mechanical mechanism into electrical signal in the existing test, simplifies the structure, and reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a simulated ball seat with a testing function of the present invention;

[0017] In the figure, 1. clamp; 2. sealing ring; 3. retention point thermometer; 4. shock-absorbing kerosene; 5. center tube; 6. first dissolution test hanging ring; 7. second dissolution test hanging ring; 8. composite material diameter test gauge; 9. sheath; 10. reset spring; 11. positioning hole; 12. lead well diameter test pin; 13. reset spring; 14. variable diameter piston; 15. first sealing ring; 16. second sealing ring; 17. liquid inlet hole; 18. connector; 19. strip hole. DETAILED DESCRIPTION

[0018] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] The present invention provides a simulated ball seat with a testing function, such as Figure 1 As shown, it includes a central tube 5, which is in the shape of a hollow cylinder with a variable diameter. A well temperature test module is arranged at one end of the central tube 5, and a dissolution test module, a ball seat passability test module, and a casing ovality test module are arranged in sequence along the central tube 5 in the direction away from the well temperature test module.

[0020] A strip hole 19 is opened at the end of the wall of the central tube 5. The well temperature test module includes a holder 1. The end of the holder 1 holds a retention point thermometer 3. One end of the holder 1 holding the retention point thermometer 3 is inserted into the strip hole 19. The retention point thermometer 3 is a glass mercury retention point thermometer. After reaching the designed position, the retention point thermometer 3 records the temperature at this location. The strip hole 19 is filled with shock-absorbing kerosene 4. A sealing ring 2 is provided at the connection between the holder 1 and the strip hole 19 to ensure that the shock-absorbing kerosene 4 will not leak.

[0021] The dissolution test module includes a first dissolution test ring 6 and a second dissolution test ring 7. A shoulder is provided at a position of the central pipe 5 away from the well temperature test module. The first dissolution test ring 6 and the second dissolution test ring 7 are both sleeved on the central pipe 5. The end face of the first dissolution test ring 6 is in contact with the shoulder. The outer diameter of the dissolution test rings 6 and 7 is the same as the outer diameter of the sealing ring of the real soluble ball seat and are made of the same soluble material. After the simulated ball seat is raised out of the wellbore, the outer diameters of the dissolution test rings 6 and 7 after dissolution are measured respectively, and then the dissolution rate of the material inside the unit is calculated according to the change of the outer diameter before and after entering the well and the time of entering the well, so as to provide a basis for the selection of soluble materials for the soluble bridge plug or the soluble ball seat.

[0022] The ball seat passability test module includes a composite material diameter test gauge 8, which is sleeved on the center tube 5. The outer wall of the composite material diameter test gauge 8 is chamfered at the top and bottom. The composite material diameter test gauge 8 is made of composite plastic material, which can undergo permanent plastic deformation. When the drill is stuck, it can be unstuck by pulling it up.

[0023] The casing ovality test module includes a plurality of lead well diameter test pins 12 and a sheath 9. The longitudinal section of the sheath 9 is "L-shaped". The sheath 9 is sleeved on the center tube 5. A positioning hole 11 is provided on the sheath 9. The lead well diameter test pin 12 is arranged in the positioning hole 11. A reducing piston 14 is provided between the sheath 9 and the center tube 5. The reducing piston 14 is sleeved on the center tube 5. The outer wall of the reducing piston 14 near the bottom of the well is chamfered. The reducing piston 14 is in sliding contact with the lead well diameter test pin 12 and slides along the surface of the reducing piston 14. The sheath 9 is provided with a liquid inlet hole 17, which is located at the location of the positioning hole 11 away from the ball seat passability test module. A reset spring 10 is arranged between the end of the variable diameter piston 14 close to the ball seat passability test module and the sheath 9, and the reset spring 10 is arranged on the central tube 5. The pressure in the wellbore acts on both sides of the variable diameter piston 14 through the liquid inlet hole 17 and the positioning hole 11 to generate a pressure difference. When the pressure in the wellbore rises to a certain value, the pressure difference is greater than the preload force of the reset spring 10, pushing the variable diameter piston 14 downward. The variable diameter piston 14 pushes the lead well diameter test pin 12 to contact the inner wall of the casing, and the length of the lead well diameter test pin 12 is shortened. By measuring the deformation degree of the lead well diameter test pin 12 caused by the casing, the inner diameter size of the casing in different directions is measured.

[0024] The areas on both sides of the variable diameter piston 14 are S2 and S1 respectively. For example, the maximum vertical well depth is 3500m, the net liquid column pressure is about 35MPa, the maximum pressure during pumping is about 30MPa, and the bottom hole pressure during pumping is about 35MPa+30MPa=65MPa. When the variable diameter piston 14 starts to move, the wellhead pressure is set to 40MPa. At this time, the pressure acting on the bottom hole is 40MPa+35MPa=75MPa. Therefore, the elastic force F of the reset spring ranges as follows:

[0025] 65(S2-S1) <F<75(S2-S1)

[0026] Meeting the above value range can ensure that the variable diameter piston 14 does not move when the tool enters the well, and the variable diameter piston 14 starts to move only when the wellhead pressure is greater than 40 MPa.

[0027] The present invention is a simulated ball seat with a testing function, and its working principle is as follows:

[0028] Connect the simulated ball seat below the simulated bridge-shooting tool string and pump it into the wellbore to complete the drilling.

[0029] During the pumping process, if there is no resistance, it means that the wellbore is unobstructed and the real soluble ball seat can also pass through the wellbore. If there is resistance, it means that the real soluble ball seat cannot pass through and needs to be processed in the wellbore later. In particular, if the composite material diameter test gauge 8 of the simulated ball seat is stuck, since it is made of composite materials, it can be unstuck by increasing the lifting force, and it will not cause the wellbore stuck drill difficult to deal with accidents.

[0030] After the soluble ball seat is sent to the designed position, the displacement is continued to be increased so that the pressure difference on both sides of the variable diameter piston 14 in the wellbore is higher than the elastic force of the reset spring 10, pushing the variable diameter piston 14 downward, and the variable diameter piston 14 drives the lead well diameter test pin 12 to extend out of the sheath 9, contact the casing wall and deform, and the variable diameter piston 14 reaches the variable diameter step of the sheath 9, the movement stops, and the length of the lead well diameter test pin 12 is squeezed to the shortest; after the pump is stopped, the pressure is reduced, and the variable diameter piston 14 returns to its original position under the action of the reset spring 10, and the lead well diameter test pin 12 returns to its initial position under the action of the reset spring 10.

[0031] When the tool string reaches the maximum position involved, the retention point thermometer 3 will record the wellbore temperature, and the dissolution test rings 6 and 7 will react with the liquid in the wellbore, which is the same as the dissolution state of the real ball seat during pumping.

[0032] When the tool string is lifted out of the wellbore, the well temperature, dissolution of soluble materials, ball seat passability, casing inner diameter and other data can be measured by checking the retention point thermometer 3, the outer diameter of the dissolution test rings 6 and 7, the composite material diameter test gauge 8 and the lead well diameter test pin 12 on the ground.

[0033] Example 1

[0034] like Figure 1 As shown, a simulated ball seat with a testing function proposed in this embodiment includes a center tube 5, which is a hollow cylinder with a variable diameter. A well temperature test module is arranged at one end of the center tube 5, and a dissolution test module, a ball seat passability test module, and a casing ovality test module are arranged in sequence on the center tube 5 in the direction away from the well temperature test module.

[0035] Example 2

[0036] like Figure 1 As shown, a simulated ball seat with a testing function proposed in this embodiment includes a center tube 5, which is a hollow cylinder with a variable diameter. A well temperature test module is arranged at one end of the center tube 5, and a dissolution test module, a ball seat passability test module, and a casing ovality test module are arranged in sequence on the center tube 5 in the direction away from the well temperature test module.

[0037] A strip hole 19 is opened at the end of the wall of the central pipe 5 . The well temperature testing module comprises a holder 1 . A retention point thermometer 3 is clamped at the end of the holder 1 . One end of the holder 1 clamping the retention point thermometer 3 is inserted into the strip hole 19 .

[0038] Example 3

[0039] like Figure 1As shown, a simulated ball seat with a testing function proposed in this embodiment includes a center tube 5, which is a hollow cylinder with a variable diameter. A well temperature test module is arranged at one end of the center tube 5, and a dissolution test module, a ball seat passability test module, and a casing ovality test module are arranged in sequence on the center tube 5 in the direction away from the well temperature test module.

[0040] A strip hole 19 is opened at the end of the wall of the central pipe 5 . The well temperature testing module comprises a holder 1 . A retention point thermometer 3 is clamped at the end of the holder 1 . One end of the holder 1 clamping the retention point thermometer 3 is inserted into the strip hole 19 .

[0041] A sealing ring 2 is provided at the connection between the clamp 1 and the strip-shaped hole 19 .

[0042] Example 4

[0043] like Figure 1 As shown, a simulated ball seat with a testing function proposed in this embodiment includes a center tube 5, which is a hollow cylinder with a variable diameter. A well temperature test module is arranged at one end of the center tube 5, and a dissolution test module, a ball seat passability test module, and a casing ovality test module are arranged in sequence on the center tube 5 in the direction away from the well temperature test module.

[0044] A strip hole 19 is opened at the end of the wall of the central pipe 5 . The well temperature testing module comprises a holder 1 . A retention point thermometer 3 is clamped at the end of the holder 1 . One end of the holder 1 clamping the retention point thermometer 3 is inserted into the strip hole 19 .

[0045] A sealing ring 2 is provided at the connection between the clamp 1 and the strip-shaped hole 19 .

[0046] The strip-shaped holes 19 are filled with shock-absorbing kerosene 4 .

Claims

1. A simulated ball seat with a test function, characterized in that: The invention comprises a central tube (5), wherein the central tube (5) is in the shape of a hollow cylinder with a variable diameter, a well temperature test module is arranged at one end of the central tube (5), and a dissolution test module, a ball seat passability test module, and a casing ovality test module are arranged in sequence along the upper edge of the central tube (5) in a direction away from the well temperature test module.

2. The simulated ball seat with testing function according to claim 1, characterized in that: A strip hole (19) is formed at the end of the wall of the central tube (5); the well temperature testing module comprises a holder (1); a retention point thermometer (3) is clamped at the end of the holder (1); one end of the retention point thermometer (3) clamped by the holder (1) is inserted into the strip hole (19).

3. The simulated ball seat with testing function according to claim 2, characterized in that: A sealing ring (2) is provided at the connection between the clamp (1) and the strip-shaped hole (19).

4. The simulated ball seat with testing function according to claim 2, characterized in that: The strip-shaped holes (19) are filled with shock-absorbing kerosene (4).

5. The simulated ball seat with testing function according to claim 1, characterized in that: The dissolution test module comprises a first dissolution test ring (6) and a second dissolution test ring (7); a shoulder is provided at a location of the central tube (5) away from the well temperature test module; the first dissolution test ring (6) and the second dissolution test ring (7) are both sleeved on the central tube (5); and the end face of the first dissolution test ring (6) is in contact with the shoulder.

6. The simulated ball seat with testing function according to claim 1, characterized in that: The ball seat passability test module comprises a composite material diameter test gauge (8), which is sleeved on the central tube (5), and the outer wall of the composite material diameter test gauge (8) is chamfered at the top and bottom.

7. The simulated ball seat with testing function according to claim 1, characterized in that: The casing ovality test module comprises a plurality of lead well diameter test pins (12) and a sheath (9), wherein the longitudinal section of the sheath (9) is "L-shaped", the sheath (9) is sleeved on the center tube (5), a positioning hole (11) is provided on the sheath (9), the lead well diameter test pin (12) is arranged in the positioning hole (11), a variable diameter piston (14) is provided between the sheath (9) and the center tube (5), the variable diameter piston (14) is sleeved on the center tube (5), the outer wall of the variable diameter piston (14) close to the bottom end of the well is chamfered, and the variable diameter piston (14) is in sliding contact with the lead well diameter test pin (12); The sheath (9) is provided with a liquid inlet hole (17), and the liquid inlet hole (17) is located at a position of the positioning hole (11) away from the ball seat passability test module; A return spring (10) is arranged between the end of the variable diameter piston (14) close to the ball seat passability test module and the sleeve (9), and the return spring (10) is arranged on the central tube (5).

Images