Perforation bidirectional shock absorber based on energy absorption material and shock absorption effect evaluation method

Abstract

The invention relates to the technical field of oil gas well oil pipe transmission perforation, in particular to a perforation bidirectional shock absorber based on an energy absorption material and a shock absorption effect evaluation method.The bidirectional shock absorber comprises two energy absorption material elements which are connected to the two ends of a shock absorption spring in series respectively; the other end of one energy absorption material element abuts against the end of the upper connector through an upper limiting gasket, and the other end of the other energy absorption material element abuts against the end of a structure formed by connecting the plug and the sliding shaft through a lower limiting gasket. By means of the bidirectional shock absorber and the shock absorption effect evaluation method, the problems that the absorption effect of low-frequency impact shock waves generated during perforation is poor and the axial bidirectional shock absorption effect is poor can be effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas well oil pipe transmission perforation, and in particular to a perforation bidirectional shock absorber based on energy absorbing material and a shock absorption effect evaluation method. Background Art

[0002] In the perforation test joint operation, the perforator generates a strong low-frequency shock wave when perforating, which propagates around the explosion point through the pipe connection link, the medium in the well and the casing wall. Therefore, effective shock absorption, vibration elimination and isolation measures must be taken to prevent the pipe and test tools from being damaged or broken by low-frequency shock.

[0003] In the prior art, a Chinese utility model patent document with publication number CN205990903U and authorization announcement date of March 1, 2017 is proposed to solve the above-mentioned technical problems. The technical solution disclosed in the patent document is as follows: a longitudinal bidirectional shock absorber for oil and gas wells, which includes an upper joint, a center rod, a plug, a sliding shaft, a shock-absorbing spring and an outer sleeve. The plug is sleeved on the outer wall of the sliding shaft, and a shear pin is provided between the plug and the sliding shaft. One end of the shock-absorbing spring is pressed against the end of the upper joint through an upper limit gasket, and the other end of the shock-absorbing spring is pressed against the end of the structure formed by the plug and the sliding shaft through a lower limit gasket. The outer sleeve is connected to the upper joint and the plug respectively, and is located between the upper joint and the plug. The center rod is located in an inner cavity formed by the connection of the upper joint and the sliding shaft, and the outer wall of the center rod is provided with two steps, one of which cooperates with the sliding shaft, and the other step cooperates with the upper limit gasket.

[0004] During the actual use of the above technical solution, the following problems may arise: the above technical solution mainly uses springs to absorb shock waves to achieve a shock-absorbing effect, which can achieve the tensile shock absorption problem to a certain extent. However, due to the high natural frequency of the spring, its absorption effect on low-frequency shock waves is poor, and the shock wave generated during perforating has the largest pressure amplitude in the low-frequency band. The shock wave in the low-frequency band has the greatest impact on the perforating string and the packer, resulting in poor axial bidirectional shock absorption effect. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a perforating bidirectional shock absorber based on energy-absorbing material and a shock absorption effect evaluation method, which can effectively solve the problems of poor absorption effect of low-frequency impact shock waves generated during perforating and poor axial bidirectional shock absorption effect.

[0006] The present invention is achieved by adopting the following technical solutions: A perforating bidirectional shock absorber based on energy-absorbing material comprises an upper joint, a center rod, a plug, a sliding shaft, a shock-absorbing spring, an upper limit gasket, a lower limit gasket, an outer sleeve and two energy-absorbing material elements respectively connected in series at both ends of the shock-absorbing spring, wherein the other end of one energy-absorbing material element abuts against the end of the upper joint via the upper limit gasket, and the other end of the other energy-absorbing material element abuts against the end of a structure formed by connecting the plug and the sliding shaft via the lower limit gasket.

[0007] The energy absorbing material element has a yield strength of more than 300 MPa, a porosity of more than 50%, and an energy absorption density of 5 J / cm 3 Made of the above metal materials.

[0008] The material microstructure of the energy absorbing material element includes a honeycomb shape and a hole shape.

[0009] The energy absorbing material element is in an annular truss structure as a whole.

[0010] The energy absorbing material element and the shock absorbing spring are located between the central rod and the outer sleeve.

[0011] Also included is an anti-rotation key disposed in the sliding shaft and the blocked keyway.

[0012] One end of the upper joint is used for connecting the drill pipe.

[0013] A method for evaluating shock absorption effect, using the above-mentioned bidirectional shock absorber; the evaluation method comprises the following steps: Step 1. Connect the first storage type temperature and pressure instrument, the two-way shock absorber, the second storage type temperature and pressure instrument and the perforator in sequence below the drill pipe; Step 2. The drill pipe transports the first storage type thermobarometer, the bidirectional shock absorber, the second storage type thermobarometer and the perforator to a predetermined position; Step 3. Ignition and perforation, the first storage-type temperature and pressure instrument records the impact force and temperature of the pipe string after shock absorption at the moment of perforation, and the second storage-type temperature and pressure instrument records the impact force and temperature of the pipe string without shock absorption at the moment of perforation; Step 4. Read the impact force data of the first storage type temperature and pressure instrument and the second storage type temperature and pressure instrument, compare and analyze the impact force, and obtain the shock absorption effect evaluation.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The shock wave generated during perforation has the largest pressure amplitude in the low-frequency band, so the shock wave in the low-frequency band has the greatest impact on the perforating pipe string and the packer. In this bidirectional shock absorber, due to the special material properties and structure of the energy-absorbing material element, it can be used in the perforating test joint operation, and efficiently absorb the low-frequency shock wave generated during perforation during the ignition and detonation process, weaken the tensile and compressive vibrations generated by the pipe string, avoid impact damage or breakage of the pipe string and the test tool, and greatly improve the axial bidirectional shock absorption effect.

[0015] 2. The microstructure of the energy-absorbing material element includes honeycomb and pores, which ensures that the material has a porosity of more than 50% and an energy absorption density of 5J / cm 3 The above characteristics can better absorb low-frequency impact vibration waves.

[0016] 3. The energy-absorbing material element is an annular truss structure as a whole. This structure collapses rapidly when subjected to low-frequency shock waves and can effectively absorb low-frequency vibration energy.

[0017] 4. The anti-rotation key is arranged in the key slot of the sliding shaft and the plug to prevent the sliding shaft and the plug from rotating relative to each other.

[0018] 5. The shock absorbing effect of the bidirectional shock absorber can be evaluated through the special structure of the bidirectional shock absorber and the corresponding evaluation method. Specifically, the evaluation method described in the present invention is used to compare and analyze the impact force data collected by the first storage-type temperature and pressure meter and the second storage-type temperature and pressure meter located in the bidirectional shock absorber, specifically including axial acceleration, downhole acceleration, wellbore pressure, temperature and other data. Since the first storage-type temperature and pressure meter records the impact force and temperature of the tubing string after shock absorption at the moment of perforation, and the second storage-type temperature and pressure meter records the impact force and temperature of the tubing string without shock absorption at the moment of perforation, there are numerical differences in the axial acceleration, downhole acceleration, wellbore pressure, temperature and other data collected by the two storage-type temperature and pressure meters. By analyzing the data differences, the shock absorbing effect of the bidirectional shock absorber can be evaluated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, wherein: Figure 1 It is a structural schematic diagram of the present invention; Figure 2 The assembly diagram of the present invention is shown in FIG. Figure 1 ; Figure 3 The assembly diagram of the present invention is shown in FIG. Figure 2 ; Figure 4 The assembly diagram of the present invention is shown in FIG. Figure 3 ; Figure 5It is a schematic diagram of the structure of the energy absorbing material element in the present invention; Figure 6 It is a schematic diagram of the cross-sectional structure of AA in the present invention; Figure 7 It is a connection diagram for evaluating the shock absorption effect in the present invention; Markings in the figure: 1. Upper joint, 2. Outer sleeve, 3. Plug, 4. Lower joint, 5. Sliding shaft, 6. Center rod, 7. Upper limit gasket, 8. Energy absorbing material element, 9. Shock-absorbing spring, 10. Shear pin, 11. Rupture disk, 12. Anti-rotation key, 13. Drill rod, 14. First storage type temperature and pressure instrument, 15. Bidirectional shock absorber, 16. Second storage type temperature and pressure instrument, 17. Perforator, 19. Lower limit gasket. DETAILED DESCRIPTION

[0020] Example 1 As a basic embodiment of the present invention, the present invention includes a perforating bidirectional shock absorber based on energy absorbing material, including an upper joint 1, a center rod 6, a plug 3, a sliding shaft 5, a shock absorbing spring 9, an upper limit gasket 7, a lower limit gasket 19, an outer sleeve 2, and two energy absorbing material elements 8 respectively connected in series at both ends of the shock absorbing spring 9. The other end of one of the energy absorbing material elements 8 is against the end of the upper joint 1 through the upper limit gasket 7, and the other end of the other energy absorbing material element 8 is against the end of the structure formed by the plug 3 and the sliding shaft 5 through the lower limit gasket 19.

[0021] Among them, this embodiment does not improve the structures of the upper joint 1, the center rod 6, the plug 3, the sliding shaft 5, the shock-absorbing spring 9, the upper limit gasket 7, the lower limit gasket 19 and the outer sleeve 2.

[0022] Example 2 As a preferred embodiment of the present invention, the present invention includes a perforating bidirectional shock absorber based on energy absorbing material, including an upper joint 1, a center rod 6, a plug 3, a sliding shaft 5, a shock absorbing spring 9, an upper limit washer 7, a lower limit washer 19, an outer sleeve 2, and two energy absorbing material elements 8 connected in series at both ends of the shock absorbing spring 9. The energy absorbing material element 8 has a yield strength of more than 300 MPa, a porosity of more than 50%, and an energy absorption density of 5 J / cm 3 The above metal materials are made, and the material microstructure includes honeycomb and hole. The other end of one energy absorbing material element 8 is against the end of the upper joint 1 through the upper limit gasket 7, and the other end of the other energy absorbing material element 8 is against the end of the structure formed by the plug 3 and the sliding shaft 5 through the lower limit gasket 19.

[0023] Example 3 As another preferred embodiment of the present invention, refer to the attached Figure 1The present invention includes a perforating bidirectional shock absorber based on energy absorbing material, including an upper joint 1, a lower joint 4, a center rod 6, a plug 3, a sliding shaft 5, a shock absorbing spring 9, an upper limit gasket 7, a lower limit gasket 19, an outer sleeve 2 and two energy absorbing material elements 8. One end of the upper joint 1 is used to connect the drill rod 13, and one end of the lower joint 4 is used to connect the perforator 17. The plug 3 is sleeved on the outer wall of the sliding shaft 5, and a shear pin 10 is provided between the plug 3 and the sliding shaft 5. The two energy absorbing material elements 8 are respectively connected in series at both ends of the shock absorbing spring 9. Under the action of the upper limit gasket 7, one of the energy absorbing material elements 8 is against the end of the upper joint 1, and under the action of the lower limit gasket 19, the other energy absorbing material element 8 is against the end of the structure formed by the plug 3 and the sliding shaft 5. The outer sleeve 2 is connected to the upper joint 1 and the plug 3 respectively, and is located between the upper joint 1 and the plug 3. The center rod 6 is located in the inner cavity formed by the connection of the upper joint 1 and the sliding shaft 5, and the outer wall of the center rod 6 is provided with two steps, one of which cooperates with the sliding shaft 5, and the other step cooperates with the upper limit gasket 7.

[0024] Refer to the instruction manual Figure 5 And the instruction manual Figure 6 The energy absorbing material element 8 is made of a metal material with high strength, high porosity and high energy absorption density. Specifically, the yield strength of the energy absorbing material element 8 is above 300 MPa, the porosity is above 50%, and the energy absorption density is above 5 J / cm 3 The metal materials include but are not limited to aluminum, calcium, magnesium and other metals and their alloys. The microstructure of the energy absorbing material element 8 includes but is not limited to honeycomb and pores. The energy absorbing material element 8 made of this material has but is not limited to a ring truss structure.

[0025] It also includes an anti-rotation key 12 arranged in the keyway of the sliding shaft 5 and the plug 3 to prevent the sliding shaft 5 and the plug 3 from rotating relative to each other. The outer sleeve is provided with a plurality of threaded damping holes and screw holes; a rupture disk 11 is arranged in the screw hole; the rupture disk 11 is a structure with thick edges and thin middle.

[0026] Refer to the instruction manual Figure 2 ~Instructions attached Figure 4 The assembly process of the perforating bidirectional shock absorber 15 based on the energy absorbing material is as follows: In the first step, the upper limit gasket 7, the lower limit gasket 19, the energy absorbing material element 8 and the shock absorbing spring 9 are installed into the center rod 6, wherein the energy absorbing material element 8 is respectively located at both ends of the shock absorbing spring 9, and the upper limit gasket 7 and the lower limit gasket 19 are respectively located at both ends of the energy absorbing material element 8.

[0027] The second step is to connect the central rod 6 with the sliding shaft 5.

[0028] The third step is to fix the anti-rotation key 12 in the keyway of the sliding shaft 5 and install the sliding shaft 5 into the plug 3.

[0029] The fourth step is to connect the sliding shaft 5 to the lower joint 4.

[0030] The fifth step is to connect the outer sleeve 2 with the plug 3.

[0031] Step 6: Connect the upper joint 1 to the outer sleeve 2 and screw in the shear pin 10.

[0032] Step 7: Screw the rupture disk 11 into the outer sleeve 2.

[0033] After assembly, the above-mentioned two-way shock absorber 15 is connected between the downhole pipe string test tool and the perforator 17. Among them, the upper joint 1 is connected to the test tool, and the lower joint 4 is connected to the perforator 17. During the process of the pipe string going down to the well and before the perforating gun is ignited, the two-way shock absorber 15 is kept in a rigid state as a whole under the action of the shear pin 10. After ignition, the shear pin 10 is sheared off under the action of the perforating detonation wave, and the two-way shock absorber 15 is in a free state. At this time, under the action of the energy-absorbing material element 8, the shock-absorbing spring 9 and the liquid in the wellbore, the violent reciprocating motion of the center rod 6 and the sliding shaft 5 in the upper joint 1 and the plug 3 caused by the detonation wave of the perforating gun can be slowed down, thereby achieving the effect of damping the test tool above the upper joint 1.

[0034] Specifically, when the center rod 6 and the sliding shaft 5 are subjected to the upward compression effect generated by the explosion wave of the perforating gun, the sliding shaft 5 moves upward to drive the lower limit gasket 19 to compress the energy absorbing material element 8 and the shock absorbing spring 9. The energy absorbing material element 8 at the other end of the shock absorbing spring 9 is fixed to the upper joint 1 under the action of the upper limit gasket 7. Thus, the shock absorbing effect of the compression impact is achieved.

[0035] When the center rod 6 and the sliding shaft 5 are subjected to the downward tensile effect of the perforating gun detonation wave, the center rod 6 moves downward to drive the upper limit gasket 7 to compress the energy absorbing material element 8 and the shock absorbing spring 9. The energy absorbing material element 8 at the other end of the shock absorbing spring 9 is fixed to the plug 3 under the action of the lower limit gasket 19. Thus, the shock absorbing effect of the tensile impact is achieved.

[0036] Example 4 As another preferred embodiment of the present invention, refer to the attached specification Figure 7 The present invention includes a shock absorption effect evaluation method, comprising the following steps: Step 1. Connect the first storage type temperature and pressure instrument 14, the bidirectional shock absorber 15, the second storage type temperature and pressure instrument 16 and the perforator 17 in sequence below the drill pipe 13. The bidirectional shock absorber 15 adopts the structure in Example 3.

[0037] Step 2. The drill pipe 13 transports the first storage type temperature and pressure instrument 14, the two-way shock absorber 15, the second storage type temperature and pressure instrument 16 and the perforator 17 to a predetermined position.

[0038] Step 3. Ignition and perforation. The first storage temperature and pressure instrument 14 will record the impact force and temperature of the pipe string after shock absorption at the moment of perforation, and the second storage temperature and pressure instrument 16 will record the impact force and temperature of the pipe string without shock absorption at the moment of perforation.

[0039] Step 4. Read the impact force data of the first storage type temperature and pressure instrument 14 and the second storage type temperature and pressure instrument 16, compare and analyze the impact force, and obtain the shock absorption effect evaluation.

[0040] In summary, after reading the present invention document, ordinary technicians in this field can make various other corresponding transformation schemes based on the technical scheme and technical concept of the present invention without creative mental labor, which all fall within the scope of protection of the present invention.

Claims

1. A perforating bidirectional shock absorber based on energy absorbing material, comprising an upper joint (1), a center rod (6), a plug (3), a sliding shaft (5), a shock absorbing spring (9), an upper limit gasket (7), a lower limit gasket (19) and an outer sleeve (2), characterized in that: It also includes two energy absorbing material elements (8) respectively connected in series at both ends of the shock absorbing spring (9), wherein the other end of one of the energy absorbing material elements (8) abuts against the end of the upper joint (1) via an upper limit washer (7), and the other end of the other energy absorbing material element (8) abuts against the end of a structure formed by connecting the plug (3) and the sliding shaft (5) via a lower limit washer (19).

2. A perforation bidirectional shock absorber based on energy absorbing material according to claim 1, characterized in that: The energy absorbing material element (8) has a yield strength of more than 300 MPa, a porosity of more than 50%, and an energy absorption density of 5 J / cm 3 Made of the above metal materials.

3. A perforation bidirectional shock absorber based on energy absorbing material according to claim 2, characterized in that: The material microstructure of the energy absorbing material element (8) includes a honeycomb shape and a hole shape.

4. A perforation bidirectional shock absorber based on energy absorbing material according to claim 3, characterized in that: The energy absorbing material element (8) is in the form of a ring-shaped truss structure as a whole.

5. The perforation bidirectional shock absorber based on energy absorbing material according to claim 1, characterized in that: The energy absorbing material element (8) and the shock absorbing spring (9) are located between the central rod (6) and the outer sleeve (2).

6. The perforation bidirectional shock absorber based on energy absorbing material according to claim 1, characterized in that: It also includes an anti-rotation key (12) arranged in the keyway of the sliding shaft (5) and the plug (3).

7. The perforation bidirectional shock absorber based on energy absorbing material according to claim 1, characterized in that: One end of the upper joint (1) is used for connecting a drill pipe (13).

8. A method for evaluating shock absorption effect, characterized in that: Utilizing the bidirectional shock absorber (15) as described in any one of claims 1 to 7 above; the evaluation method comprises the following steps: Step 1. Connect the first storage type thermobarometer (14), the bidirectional shock absorber (15), the second storage type thermobarometer (16) and the perforator (17) in sequence below the drill pipe (13); Step 2. The drill pipe (13) transports the first storage type thermobarometer (14), the bidirectional shock absorber (15), the second storage type thermobarometer (16) and the perforator (17) to a predetermined position; Step 3. Ignite and perforate, the first storage-type temperature and pressure instrument (14) records the impact force and temperature of the pipe string after shock absorption at the moment of perforation, and the second storage-type temperature and pressure instrument (16) records the impact force and temperature of the pipe string without shock absorption at the moment of perforation; Step 4. Read the impact force data of the first storage type temperature and pressure instrument (14) and the second storage type temperature and pressure instrument (16), compare and analyze the impact force, and obtain the shock absorption effect evaluation.

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