Thermal insulation perforating gun for thermal exploitation oil and gas well

Abstract

The invention discloses a thermal-insulation perforating gun for a thermal exploitation oil-gas well, which comprises a thermal-insulation gun tail, a plurality of thermal-insulation perforating gun tubes and an exploder which are connected in sequence, the plurality of thermal-insulation perforating gun tubes are connected through thermal-insulation intermediate joints, and the exploder is connected with the thermal-insulation perforating gun tubes through thermal-insulation exploder joints; the heat insulation perforating gun barrel is a double-layer concentric tubular column, the space between the double-layer concentric tubular column is filled with heat insulation materials, the space between the double-layer concentric tubular column is in a vacuum state, heat insulation linings are arranged in the heat insulation middle connector, the heat insulation gun tail and the heat insulation exploder connector, and the outer side of the exploder is sleeved with a heat insulation protection pipe short section. Aiming at a perforation operation technology in a high-temperature environment of a thermal exploitation oil and gas well stratum, three heat insulation technologies of heat convection blocking, heat reflection and vacuumizing are applied to isolate the high temperature of the stratum outside the heat insulation perforating gun, so that the internal temperature of the heat insulation perforating gun meets the temperature resistance index of an initiating explosive device.

Description

Technical Field

[0001] The invention belongs to the field of petroleum exploitation, in particular to a heat-insulating perforating gun for thermal exploitation of oil and gas wells. Background Art

[0002] For high-temperature and ultra-high-temperature perforating operations in thermal oil and gas wells, the following perforating methods are currently mainly adopted: First, the temperature resistance of the perforating equipment is utilized, and the perforating equipment of the corresponding temperature level is used according to the well temperature of the perforating target layer of the construction well. For example, for wells with well temperatures exceeding 120°C and below 163°C in oil pipe conveying perforating wells (perforating safety time is not less than 48h), high-temperature perforating equipment is used; for wells with well temperatures exceeding 163°C, ultra-high-temperature perforating equipment is used. Second, for wells with well temperatures higher than the temperature resistance level of the perforating equipment, the temperature in the wellbore is reduced by circulating cold water. The temperature of the perforating section and the temperature from the perforating section to the wellhead must be reduced before the perforating operation can be carried out. Third, before the perforating operation, the steam injection operation of the steam injection wells within 200m around the construction well is stopped, and the formation temperature is allowed to drop to the temperature resistance index of the perforating equipment before the perforating operation is carried out.

[0003] The above perforating methods can complete the perforating operation under high-temperature well conditions, but they also have limitations. The temperature resistance of perforating equipment is determined by the temperature resistance index of pyrotechnics. Since the perforator is assembled from a variety of pyrotechnics such as perforating bullets, detonating cords, booster tubes, detonators, etc., the temperature resistance level of the perforator is based on the lowest temperature resistance level among the pyrotechnics. Therefore, the temperature resistance of perforating equipment is limited by the temperature resistance index of pyrotechnics. According to data, the current maximum well temperature of perforating operations completed by the temperature resistance of perforating equipment is 230℃. In addition, the raw materials of high-temperature and ultra-high-temperature pyrotechnics cannot meet production needs due to special reasons such as limited output and transportation supervision. The method of cooling by cold water circulation and stopping steam injection is to use physical methods to cool down the formation temperature of the steam chamber of the construction well and the surrounding wells, which is a measure of external intervention. This measure takes a long time to implement and has large losses. The most critical thing is that after the formation temperature field is cooled, the fluidity of fluids such as heavy oil in the formation is reduced, which is not conducive to the exploitation of heavy oil. Summary of the invention

[0004] The purpose of the present invention is to solve the problems in the prior art and provide a heat-insulating perforating gun for thermal production oil and gas wells to solve the problem of large limitations in high-temperature and ultra-high-temperature perforating operations in thermal production oil and gas wells.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A thermal insulation perforating gun for thermal exploitation of oil and gas wells, comprising a thermal insulation gun tail, a plurality of thermal insulation perforating gun barrels and a detonator connected in sequence, wherein the plurality of thermal insulation perforating gun barrels are connected by thermal insulation intermediate joints, and the detonator is connected to the thermal insulation perforating gun barrel through a thermal insulation detonator joint;

[0007] The thermal insulation perforating gun barrel is a double-layer concentric pipe column, and the double-layer concentric pipe columns are filled with thermal insulation materials. There is a vacuum state between the double-layer concentric pipe columns. The thermal insulation middle joint, the thermal insulation gun tail and the thermal insulation detonator joint are all provided with thermal insulation bushings, and the outer side of the detonator is provided with a thermal insulation protective pipe short section.

[0008] Furthermore, the double-layer concentric pipe column includes an outer barrel and an inner barrel, an annular space is formed between the outer barrel and the inner barrel, the thermal insulation material is filled in the annular space, and both ends of the annular space are sealed by welding rings.

[0009] Furthermore, the thermal insulation material includes glass fiber cloth, aluminum foil and a hydrogen absorbent.

[0010] Furthermore, the thermal insulation middle joint includes a thermal insulation upper joint and a thermal insulation lower joint, and the thermal insulation upper joint and the thermal insulation lower joint are connected by threads.

[0011] Furthermore, the thermal insulation bushing in the thermal insulation middle joint is a first thermal insulation bushing, and the first thermal insulation bushing is arranged in the middle diameter of the thermal insulation lower joint.

[0012] Furthermore, the heat-insulating bushing in the heat-insulating gun butt is a second heat-insulating bushing, and the second heat-insulating bushing is arranged in the middle diameter of the heat-insulating gun butt.

[0013] Furthermore, the interior of the thermal insulation bushing is filled with nano thermal insulation material and hydrogen absorbent.

[0014] Furthermore, the thermal insulation detonator joint is connected to the thermal insulation oil pipe.

[0015] Furthermore, one end of the thermal insulation protection pipe short section is connected to the thermal insulation detonator joint, and the other end of the thermal insulation protection pipe short section is connected to the depth calibration pipe string.

[0016] Furthermore, the thermal insulation detonator joint is connected to the thermal insulation perforating gun barrel through a thread, and the thermal insulation perforating gun barrel is connected to the thermal insulation gun tail through a thread.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention provides an insulated perforating gun for thermal exploitation oil and gas wells, wherein an insulated gun tail, several sections of insulated perforating gun barrels and a detonator are connected and sealed in sequence, a double-layer structure is designed for components such as the insulated perforating gun barrel, the insulated intermediate joint, the insulated detonator joint and the insulated gun tail, the annular space is filled with insulation materials, and an insulation protection pipe short section is sleeved on the outside of the detonator. The present invention is aimed at the perforating operation technology under the high temperature environment of the formation of thermal exploitation oil and gas wells, and applies three insulation technologies of heat convection blocking, heat reflection and vacuuming to isolate the high temperature of the external formation of the insulated perforating gun, so that the internal temperature of the insulated perforating gun meets the temperature resistance index of the pyrotechnics. Through the analysis of the temperature test results of the insulated perforating gun string, the insulated perforating gun barrel has a temperature difference of 170°C inside and outside the insulated perforating gun barrel wall under a temperature environment of 300°C, with a temperature drop of 57%. The temperature difference between the inside and outside of the insulation joint reaches 130°C, with a temperature drop of 43%. The heat-insulating perforating gun of the present invention has good heat-insulating performance, and provides a new technical means for achieving safe perforating operation in thermal oil and gas wells without cooling by cold water circulation or stopping injection of surrounding steam injection wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of the structure of the heat-insulating perforating gun for thermal production of oil and gas wells according to the present invention.

[0021] Figure 2 It is a schematic diagram of the structure of the heat-insulating perforating gun barrel of the present invention.

[0022] Figure 3 It is a schematic diagram of the structure of the thermal insulation lower joint of the present invention.

[0023] Figure 4 It is a schematic diagram of the heat-insulating gun tail structure of the present invention.

[0024] Figure 5 It is a schematic diagram of the connection of the detonator of the present invention.

[0025] Among them: 1-insulated perforating gun barrel, 11-outer gun barrel, 12-inner gun barrel, 13-welding ring, 2-insulated middle joint, 21-insulated upper joint, 22-insulated lower joint, 23-first insulating bushing, 3-insulated gun tail, 31-second insulating bushing, 4-detonator, 41-insulated protective tube short section, 42-insulated detonator joint, 5-thread. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0029] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0030] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0031] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0033] The commonly used gun body perforating gun usually consists of a gun head, gun body, joint and gun tail to form a completely closed cavity. Its function is to protect the perforating bullets, bullet racks, detonating cords, booster tubes and detonators in the gun from the influence of complex environments such as underground high pressure, acid and alkali, and vibration and impact generated during construction, so as to ensure the reliable detonation of the detonating cord and the detonation of the perforating bullets to complete the perforation.

[0034] For perforating operations in thermal oil and gas wells, the perforating gun not only has the above functions, but more importantly, it must also have good heat insulation. Figure 1 The present invention provides a thermal insulation perforating gun for thermal exploitation oil and gas wells, comprising a thermal insulation perforating gun barrel 1, a thermal insulation middle joint 2, a thermal insulation gun tail 3 and a detonator 4. The thermal insulation gun tail 3, several sections of the thermal insulation perforating gun barrel 1 and the detonator 4 are connected in sequence, the detonator 4 is connected to the thermal insulation perforating gun barrel 1 through the thermal insulation detonator joint 42, and several sections of the thermal insulation perforating gun barrel 1 are connected through the thermal insulation middle joint 2, and the thermal insulation perforating gun barrel 1 is connected to the thermal insulation gun tail 3 through the thread 5 to form a sealed environment. A double-layer structure is designed for the thermal insulation perforating gun barrel 1, the thermal insulation middle joint 2, the detonator 4 and the thermal insulation gun tail 3, and the annular space is filled with insulation materials. The three major insulation technologies of heat convection blocking, heat reflection and vacuuming are applied to isolate the high temperature of the external formation of the thermal insulation perforating gun, so that the internal temperature of the thermal insulation perforating gun meets the temperature resistance index of the pyrotechnics.

[0035] like Figure 2 As shown, the thermal insulation perforating gun barrel 1 is a double-layer concentric pipe column, and its basic structure includes an outer gun barrel 11 and an inner gun barrel 12. An annular space is formed between the outer gun barrel 11 and the inner gun barrel 12, and the annular space of the two-layer gun barrel is filled with thermal insulation materials, mainly glass fiber cloth and aluminum foil are wrapped around the outer side of the inner gun barrel 12, and then filled with an appropriate amount of hydrogen absorbent. After the inner and outer gun barrels are inserted, the two ends of the annular space are connected by ring welding and sealed by a welding ring 13. Finally, the annular space of the thermal insulation perforating gun barrel 1 is vacuumed.

[0036] This structure can delay the trend of decreasing thermal insulation performance as the thermal insulation grade increases over time, so that the thermal insulation perforating gun barrel 1 maintains good thermal insulation performance in a long-term high-temperature environment. In order to prevent the bending of the double-layer thermal insulation perforating gun barrel 1 and cracking of the welding ring 13 due to prestress, a prestress compensation technology can be used to compensate for the temperature difference elongation of the inner and outer barrels, ensuring that the thermal insulation perforating gun barrel 1 has reliable mechanical properties in a high-temperature environment.

[0037] like Figure 3As shown, the insulating middle joint 2 includes an insulating upper joint 21 and an insulating lower joint 22, and the insulating upper joint 21 and the insulating lower joint 22 are connected by a thread 5. The insulating function of the insulating middle joint 2 is mainly undertaken by the insulating lower joint 22. A first insulating bushing 23 that can penetrate the insulating upper joint 21 is arranged in the middle diameter of the insulating lower joint 22, and the first insulating bushing 23 is used to isolate the external high temperature. Since the internal space of the interlayer of the first insulating bushing 23 is very small, the structure cannot be filled with insulating materials such as glass fiber cloth and aluminum foil, and it cannot be vacuumed, so nano-insulating materials and hydrogen absorbents are used for filling to maintain good insulating properties.

[0038] The heat-insulating upper joint 21 only serves to connect the heat-insulating lower joint 22 and the next heat-insulating perforating gun barrel 1 , and therefore, no heat-insulating structure is provided, and the heat-insulating lower joint 22 is matched to form a complete set of heat-insulating middle joints 2 .

[0039] like Figure 4 As shown, the heat-insulating gun tail 3 adopts the structure of the second heat-insulating bushing 31, which has the same heat-insulating structure design and heat-insulating principle as the heat-insulating lower joint 22. The annular space of the interlayer of the second heat-insulating bushing 31 is filled with nano heat-insulating materials and hydrogen absorbents, etc., which can isolate the high temperature outside the heat-insulating perforating gun tail.

[0040] like Figure 5 As shown, the structure of the insulated detonator joint 42 is basically the same as the insulated intermediate joint 2. The lower end of the insulated detonator joint 42 is connected to the insulated perforating gun barrel 1 through the thread 5, and the upper end is connected to both the detonator 4 and the insulated oil pipe. Since the detonator 4 does not have a heat insulation function, an insulated protective tube short section 41 is sleeved on the outer side of the detonator 4, and the upper end of the insulated protective tube short section 41 is connected to the depth calibration pipe column. First, the detonator 4 is installed on the insulated perforating gun barrel 1, and then the detonator 4 is inserted into the insulated protective tube short section 41. The insulated protective tube short section 41 is connected to the detonator thermal insulation joint 42, which can better solve the heat insulation problem of the detonator 4.

[0041] The present invention applies three major thermal insulation technologies, namely, heat convection blocking, heat reflection and vacuum extraction, and uses normal temperature perforating equipment. Without cold water circulation cooling or suspending injection of surrounding steam injection wells, safe perforating operations can be achieved under high temperature and ultra-high temperature well conditions by relying on the thermal insulation performance of the thermal insulation perforating gun itself. The invention is simple to operate and highly practical, and provides a new technical means for achieving safe perforating operations.

[0042] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A heat-insulating perforating gun for thermal production of oil and gas wells, It is characterized in that It comprises a heat-insulating gun tail (3), a plurality of heat-insulating perforating gun barrels (1) and a detonator (4) connected in sequence, wherein the plurality of heat-insulating perforating gun barrels (1) are connected via a heat-insulating intermediate joint (2), and the detonator (4) is connected to the heat-insulating perforating gun barrel (1) via a heat-insulating detonator joint (42); The heat-insulating perforating gun barrel (1) is a double-layer concentric pipe column, the double-layer concentric pipe columns are filled with heat-insulating materials, and the double-layer concentric pipe columns are in a vacuum state. The heat-insulating middle joint (2), the heat-insulating gun tail (3) and the heat-insulating detonator joint (42) are all provided with heat-insulating bushings, and the outer side of the detonator (4) is provided with a heat-insulating protective pipe short section (41).

2. A heat-insulating perforating gun for thermal production of oil and gas wells according to claim 1, It is characterized in that The double-layer concentric pipe column comprises an outer barrel (11) and an inner barrel (12), an annular space is formed between the outer barrel (11) and the inner barrel (12), the heat insulating material is filled in the annular space, and both ends of the annular space are sealed by welding rings (13).

3. A heat-insulating perforating gun for thermal exploitation of oil and gas wells according to claim 1 or 2, It is characterized in that The heat insulating material comprises glass fiber cloth, aluminum foil and a hydrogen absorbent.

4. The heat-insulating perforating gun for thermal production of oil and gas wells according to claim 1, It is characterized in that The thermal insulation middle joint (2) comprises a thermal insulation upper joint (21) and a thermal insulation lower joint (22), and the thermal insulation upper joint (21) and the thermal insulation lower joint (22) are connected via a thread (5).

5. The heat-insulating perforating gun for thermal production of oil and gas wells according to claim 1, It is characterized in that The heat-insulating bushing in the heat-insulating middle joint (2) is a first heat-insulating bushing (23), and the first heat-insulating bushing (23) is arranged in the middle diameter of the heat-insulating lower joint (22).

6. The heat-insulating perforating gun for thermal production of oil and gas wells according to claim 1, It is characterized in that The heat-insulating bushing in the heat-insulating gun butt (3) is a second heat-insulating bushing (31), and the second heat-insulating bushing (31) is arranged in the middle diameter of the heat-insulating gun butt (3).

7. The heat-insulating perforating gun for thermal oil and gas wells according to claim 1, It is characterized in that The interior of the heat-insulating bushing is filled with nano heat-insulating material and hydrogen absorbent.

8. The heat-insulating perforating gun for thermal oil and gas wells according to claim 1, It is characterized in that The thermal insulation detonator joint (42) is connected to the thermal insulation oil pipe.

9. The heat-insulating perforating gun for thermal production of oil and gas wells according to claim 1, It is characterized in that One end of the heat-insulating protection pipe short section (41) is connected to the heat-insulating detonator joint (42), and the other end of the heat-insulating protection pipe short section (41) is connected to the depth calibration pipe column.

10. The heat-insulating perforating gun for thermal exploitation of oil and gas wells according to claim 1, It is characterized in that The heat-insulating detonator joint (42) is connected to the heat-insulating perforating gun barrel (1) via a thread (5), and the heat-insulating perforating gun barrel (1) is connected to the heat-insulating gun tail (3) via a thread (5).

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