阅读说明：本技术 一种利用co2循环的地热开发双层复合连续管及其使用方法 (By using CO2Circulating geothermal development double-layer composite continuous pipe and use method thereof ) 是由 刘强 梁政 王行运 蒋发光 赵广慧 张灵军 叶哲伟 张书军 张梁 刘艳平 段建良 于 2021-09-22 设计创作，主要内容包括：本发明涉及一种利用CO-(2)循环的地热开发双层复合连续管及其使用方法,属于井下取热设备技术领域。技术方案是：通过井口设备将液态CO-(2)注入到循环内管组件内,液态CO-(2)从节流嘴(10)喷出,喷出后压力降低,同时在地层高温段取热,液态CO-(2)快速气化变为气体,气态CO-(2)在循环外管换热管(17)内通过热交换吸收地层热量后,从循环内管组件与循环外管组件之间的环状空间向上返回,历经内部焊接过渡管(16)、外管焊接过渡管(15)和循环外管保温段后到达井口排出至井口设备。本发明的积极效果：解决地下取热成本高、效果差、采收率低等问题,从而实现井下取热。(The invention relates to a method for utilizing CO 2 A double-layer composite continuous pipe for cyclic geothermal development and a use method thereof belong to the technical field of underground heat-taking equipment. The technical scheme is as follows: passing liquid CO through wellhead equipment 2 Injecting liquid CO into the circulating inner pipe assembly 2 Is sprayed out from the throttling nozzle (10), the pressure is reduced after the spraying, and simultaneously, the heat is taken at the high-temperature section of the stratum, and the liquid CO is 2 Quickly gasified to become gas, gaseous CO 2 After absorbing formation heat through heat exchange in the circulation outer tube heat exchange tube (17), the heat returns upwards from the annular space between the circulation inner tube assembly and the circulation outer tube assembly, passes through the internal welding transition tube (16), the outer tube welding transition tube (15) and the circulation outer tube heat preservation section, reaches a wellhead and is discharged to wellhead equipment. The invention has the following positive effects: the problems of high cost, poor effect, low recovery ratio and the like of underground heat extraction are solved, and therefore underground heat extraction is achieved.)

1. By using CO₂The double-layer composite continuous pipe for circulating geothermal development is characterized in that: the circulating device comprises an outer circulating pipe assembly and an inner circulating pipe assembly which are sleeved inside and outside, wherein the bottom of the outer circulating pipe assembly is closed;

the circulating inner tube assembly comprises a circulating inner tube tensile layer (1), a circulating inner tube inner temperature layer (2), a circulating inner tube outer heat preservation layer (3), a circulating inner tube righting support (4), a righting clamp ring (5), a circulating inner tube lower connector (6), a circulating inner tube weighted pipe (7), a circulating inner tube weighted pipe connector (8), a circulating inner tube bottom guide head (9), a throttling nozzle (10) and a throttling nozzle fixing plug (11); the circulating inner tube heat-insulating section is formed by sequentially arranging a circulating inner tube tensile layer (1), a circulating inner tube inner thermal layer (2) and a circulating inner tube outer heat-insulating layer (3) from inside to outside, two ends of the circulating inner tube heat-insulating section are respectively provided with two righting snap rings (5), a plurality of circulating inner tube righting supports (4) are uniformly distributed on the outer ring of the circulating inner tube heat-insulating section, two ends of each circulating inner tube righting support (4) are respectively fixed on the two righting snap rings (5), one end of the circulating inner tube tensile layer (1) is connected with one end of a circulating inner tube lower connector (6), the other end of the circulating inner tube lower connector (6) is in threaded connection with one end of a circulating inner tube weighted pipe (7), the other end of the circulating inner tube weighted pipe (7) is in threaded connection with one end of a circulating inner tube bottom guide head (9) through a circulating inner tube weighted pipe connector (8), and the other end of the circulating inner tube bottom guide head (9) is in threaded connection with a throttling nozzle fixing screw plug (11), the flow interception nozzle (10) is positioned between the bottom guide head (9) of the circulating inner tube and the throttling nozzle fixing plug (11);

the circulating outer pipe assembly comprises a circulating outer pipe outer tensile layer (12), a circulating outer pipe inner and outer interlayer heat insulation layer (13), a circulating outer pipe inner tensile layer (14), an outer pipe welding transition pipe (15), an inner welding transition pipe (16), a circulating outer pipe heat exchange pipe (17) and a circulating outer pipe lower guide head (18); the outer tensile layer (12) of the circulating outer pipe, the inner and outer interlayer insulating layer (13) of the circulating outer pipe and the inner tensile layer (14) of the circulating outer pipe are sequentially arranged from inside to outside to form a circulating outer pipe insulating section; one end of the inner tensile layer (14) of the circulating outer pipe and one end of the inner and outer interlayer heat-insulating layers (13) of the circulating outer pipe extend out of the outer tensile layer (12) of the circulating outer pipe, the extending ends of the two ends are welded with one end of the inner welding transition pipe (16), the outer welding transition pipe (15) is sleeved outside the inner and outer interlayer heat-insulating layers (13) of the circulating outer pipe and the inner welding transition pipe (16), one end of the outer welding transition pipe (15) is welded with one end of the outer tensile layer (12) of the circulating outer pipe, the inner wall of the outer welding transition pipe (15) is welded with the inner and outer interlayer heat-insulating layers (13) of the circulating outer pipe and the outer wall of the inner welding transition pipe (16), the other end of the outer welding transition pipe (15) is welded with one end of a heat exchange pipe (17) of the circulating outer pipe, and the other end of the outer pipe (17) of the circulating outer pipe is welded with a guide head (18) on the lower portion of the circulating outer pipe.

2. A method of using CO as claimed in claim 1₂The double-layer composite continuous pipe for circulating geothermal development is characterized in that: the circulating inner pipe centering support (4) is of a strip structure with two inwards bent ends, and the bent ends are welded with the outer wall of the centering clamping ring (5).

3. A method of using CO as claimed in claim 1 or 2₂The double-layer composite continuous pipe for circulating geothermal development is characterized in that: and the upper ends of the heat preservation section of the circulation inner pipe and the heat preservation section of the circulation outer pipe are both in threaded connection with wellhead equipment.

4. According to the rightUse of CO according to claim 1 or 2₂The double-layer composite continuous pipe for circulating geothermal development is characterized in that: the two righting snap rings (5) are connected to the heat preservation section of the circulating inner pipe through respective bolts.

5. A method of using CO as claimed in claim 1 or 2₂The double-layer composite continuous pipe for circulating geothermal development is characterized in that: the number of the circulating inner tube righting supports (4) is four.

6. By using CO₂Use of a double-layer composite continuous pipe for cyclic geothermal development, according to any of claims 1 to 5, characterized in that:

the circulating outer pipe assembly and the circulating inner pipe assembly of the double-layer composite continuous pipe are both connected with wellhead equipment, and the double-layer composite continuous pipe is placed into a geothermal well; passing liquid CO through wellhead equipment₂Is injected into the tensile layer (1) of the inner circulation pipe from the top of the heat preservation section of the inner circulation pipe, passes through the lower joint (6) of the inner circulation pipe, the weighting pipe (7) of the inner circulation pipe, the weighting pipe joint (8) of the inner circulation pipe, the bottom guide head (9) of the inner circulation pipe, the throttling nozzle (10) and the throttling nozzle fixing plug (11), and liquid CO₂Is sprayed out from the throttling nozzle (10), the pressure is reduced after the spraying, and simultaneously, the heat is taken at the high-temperature section of the stratum, and the liquid CO is₂Quickly gasified to become gas, gaseous CO₂After absorbing formation heat through heat exchange in the circulation outer tube heat exchange tube (17), the heat returns upwards from the annular space between the circulation inner tube assembly and the circulation outer tube assembly, passes through the internal welding transition tube (16), the outer tube welding transition tube (15) and the circulation outer tube heat preservation section, reaches a wellhead and is discharged to wellhead equipment.

Technical Field

The invention relates to a method for utilizing CO₂A double-layer composite continuous pipe for cyclic geothermal development and a use method thereof belong to the technical field of underground heat-taking equipment.

Background

Geothermal heat is a plentiful, clean, renewable energy source, CO₂Resource utilization and geological storage technology are considered as an important measure for reducing greenhouse gas emission and relieving climate warming. Introducing CO₂The idea of resource utilization is applied to geothermal development and CO utilization₂Replaces water as a working medium, carries out circular geothermal heat carrying, and utilizes CO compared with other working media₂Can improve the property of heat storage, can improve the recovery ratio of geothermal heat, has obvious economic and environmental protection benefits, and is a novel geothermal development technology.

Aiming at the current situations of high cost, poor effect and low recovery ratio of conventional underground heat extraction, a convenient and effective underground heat extraction tool is needed, and underground heat extraction can be effectively realized.

Disclosure of Invention

The invention aims to provide a method for utilizing CO₂The double-layer composite continuous pipe for cyclic geothermal development and its usage can be used for quickly connecting well head equipment with CO₂As working medium, injecting liquid CO into the top of the double-layer composite continuous pipe circulating inner pipe assembly₂After heat is extracted from the geothermal layer, liquid CO₂Gasification of gaseous CO₂Extracting gaseous CO with heat along an annulus between a circulating inner tube assembly and a circulating outer tube assembly_2，The underground heat extraction is transmitted to the aboveground equipment, so that the underground heat extraction is realized, and the problems in the background art are solved.

The technical scheme of the invention is as follows:

by using CO₂The circulating geothermal development double-layer composite continuous pipe comprises a circulating outer pipe assembly and a circulating inner pipe assembly which are sleeved inside and outside, wherein the bottom of the circulating outer pipe assembly is closed;

the circulating inner tube assembly comprises a circulating inner tube tensile layer, a circulating inner tube inner temperature layer, a circulating inner tube outer heat insulation layer, a circulating inner tube righting support, a righting clamping ring, a circulating inner tube lower connector, a circulating inner tube weighted tube connector, a circulating inner tube bottom guide head, a throttling nozzle and a throttling nozzle fixing plug; the circulation inner tube tensile layer, the circulation inner tube inner temperature layer and the circulation inner tube outer heat preservation layer are sequentially arranged from inside to outside to form a circulation inner tube heat preservation section, two ends of the circulation inner tube heat preservation section are respectively provided with two righting clamp rings, a plurality of circulation inner tube righting supports are uniformly distributed on the outer ring of the circulation inner tube heat preservation section, two ends of each circulation inner tube righting support are respectively fixed on the two righting clamp rings, one end of the circulation inner tube tensile layer is connected with one end of a circulation inner tube lower connector, the other end of the circulation inner tube lower connector is in threaded connection with one end of a circulation inner tube weighting tube, the other end of the circulation inner tube weighting tube is in threaded connection with one end of a circulation inner tube bottom guide head through the circulation inner tube weighting tube connector, the other end of the circulation inner tube bottom guide head is in threaded connection with a throttling nozzle fixing screwed plug, and a throttling nozzle is positioned between the circulation inner tube bottom guide head and the throttling nozzle fixing screwed plug;

the circulating outer pipe assembly comprises a circulating outer pipe outer tensile layer, a circulating outer pipe inner and outer interlayer heat insulation layer, a circulating outer pipe inner tensile layer, an outer pipe welding transition pipe, an inner welding transition pipe, a circulating outer pipe heat exchange pipe and a circulating outer pipe lower guide head; the outer tensile layer of the circulating outer pipe, the inner and outer interlayer heat preservation layers of the circulating outer pipe and the inner tensile layer of the circulating outer pipe are sequentially arranged from inside to outside to form a heat preservation section of the circulating outer pipe; the one end of tensile layer in the circulation outer tube and the one end of intermediate layer heat preservation all stretch out outside the circulation outer tube tensile layer in the circulation outer tube, both stretch out the end and all weld with the one end of inside weld transition pipe, outer tube weld transition pipe is established outside intermediate layer heat preservation and the inside weld transition pipe in the circulation outer tube, outer tube weld transition pipe one end welds with circulation outer tube outside tensile layer one end, outer tube weld transition pipe inner wall welds with circulation outer tube inside and outside intermediate layer heat preservation and inside weld transition pipe outer wall, the outer tube weld transition pipe other end welds with circulation outer tube heat exchange tube one end, the circulation outer tube heat exchange tube other end welds with circulation outer tube lower part direction head.

The circulation inner tube righting support is of a strip structure with two ends bent inwards, the bent ends are welded with the outer wall of the righting snap ring, and a small gap is reserved between the circulation inner tube righting support and the inner tensile layer of the circulation outer tube to prevent the circulation inner tube assembly from being inclined.

And the upper ends of the heat preservation section of the circulation inner pipe and the heat preservation section of the circulation outer pipe are both in threaded connection with wellhead equipment.

And the two righting snap rings are connected to the heat preservation section of the circulating inner pipe through respective bolts.

The number of the circulating inner tube righting supports is four.

The lower part guide head of the circulation outer pipe is of a tubular structure with the lower end blocked, and the other end of the heat exchange pipe of the circulation outer pipe extends into the lower part guide head of the circulation outer pipe and is welded together.

By using CO₂The use method of the double-layer composite continuous pipe for the cyclic geothermal development comprises the following steps of:

the circulating outer pipe assembly and the circulating inner pipe assembly of the double-layer composite continuous pipe are both connected with wellhead equipment, and the double-layer composite continuous pipe is placed into a geothermal well; passing liquid CO through wellhead equipment₂From the circulation inner pipeThe top of the heat preservation section is injected into the tensile layer of the circulation inner tube, and the liquid CO passes through the lower joint of the circulation inner tube, the weighting tube joint of the circulation inner tube, the guide head at the bottom of the circulation inner tube, the throttle nozzle and the throttle nozzle fixing plug₂Is sprayed out from the throttling nozzle, the pressure is reduced after the spraying, and simultaneously the heat and liquid CO are taken at the high-temperature section of the stratum₂Quickly gasified to become gas, gaseous CO₂After the heat of the formation is absorbed through heat exchange in the heat exchange pipe of the circulating outer pipe, the heat returns upwards from the annular space between the assembly of the circulating inner pipe and the assembly of the circulating outer pipe, passes through the internal welding transition pipe, the welding transition pipe of the outer pipe and the heat preservation section of the circulating outer pipe, reaches a wellhead and is discharged to wellhead equipment.

The invention has the following positive effects: the problems of high cost, poor effect, low recovery ratio and the like of underground heat extraction are solved, and therefore underground heat extraction is achieved.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the inner circulation pipe assembly of the present invention;

FIG. 3 is a schematic top view of the centering collar of the present invention;

FIG. 4 is a bottom view of the choke retaining plug of the present invention;

FIG. 5 is a sectional view of a heat-insulating section of the inner circulation pipe according to the present invention;

FIG. 6 is a schematic structural view of the annular outer tube assembly of the present invention;

FIG. 7 is a sectional view of a heat retaining section of the outer circulation tube of the present invention;

in the figure: 1. circulating the inner tube tensile layer; 2. circulating an inner tube inner temperature layer; 3. circulating the outer heat-insulating layer of the inner pipe; 4. a circulating inner pipe righting support; 5. righting the snap ring; 6. a circulating inner pipe lower joint; 7. a circulating inner tube weighted tube; 8. a circular inner pipe weighting pipe joint; 9. circulating the guiding head at the bottom of the inner pipe; 10. a throttle nozzle; 11. the throttling nozzle is fixed with the plug; 12. circulating the outer tensile layer of the outer pipe; 13. an inner interlayer insulating layer and an outer interlayer insulating layer of the circulating outer pipe; 14. circulating the tensile layer in the outer tube; 15. welding a transition pipe on the outer pipe; 16. welding a transition pipe inside; 17. circulating the outer pipe heat exchange pipe; 18. and circulating the lower guide head of the outer tube.

Detailed Description

The invention is further described with reference to the following figures and examples:

by using CO₂The circulating geothermal development double-layer composite continuous pipe comprises a circulating outer pipe assembly and a circulating inner pipe assembly which are sleeved inside and outside, wherein the bottom of the circulating outer pipe assembly is closed;

the circulating inner tube assembly comprises a circulating inner tube tensile layer 1, a circulating inner tube inner temperature layer 2, a circulating inner tube outer heat preservation layer 3, a circulating inner tube righting support 4, a righting clamping ring 5, a circulating inner tube lower connector 6, a circulating inner tube weighted pipe 7, a circulating inner tube weighted pipe connector 8, a circulating inner tube bottom guide head 9, a throttling nozzle 10 and a throttling nozzle fixing plug 11; the tensile layer 1 of the inner pipe is circulated, the circulating inner pipe inner temperature layer 2 and the circulating inner pipe outer heat preservation layer 3 are sequentially arranged from inside to outside to form a circulating inner pipe heat preservation section, two ends of the circulating inner pipe heat preservation section are respectively provided with two righting snap rings 5, four circulating inner pipe righting supports 4 are uniformly distributed on the outer ring of the circulating inner pipe heat preservation section, two ends of each circulating inner pipe righting support 4 are respectively fixed on the two righting snap rings 5, one end of a circulating inner pipe tensile layer 1 is connected with one end of a circulating inner pipe lower connector 6, the other end of the circulating inner pipe lower connector 6 is in threaded connection with one end of a circulating inner pipe weighting pipe 7, the other end of the circulating inner pipe weighting pipe 7 is in threaded connection with one end of a circulating inner pipe bottom guide head 9 through a circulating inner pipe weighting pipe connector 8, the other end of the circulating inner pipe bottom guide head 9 is in threaded connection with a throttling nozzle fixing screwed plug 11, and a shutoff nozzle 10 is positioned between the circulating inner pipe bottom guide head 9 and the throttling nozzle fixing screwed plug 11;

the circulating outer pipe assembly comprises a circulating outer pipe outer tensile layer 12, a circulating outer pipe inner and outer interlayer heat insulation layer 13, a circulating outer pipe inner tensile layer 14, an outer pipe welding transition pipe 15, an inner welding transition pipe 16, a circulating outer pipe heat exchange pipe 17 and a circulating outer pipe lower part guide head 18; the outer tensile layer 12 of the circulating outer pipe, the inner and outer interlayer insulating layer 13 of the circulating outer pipe and the inner tensile layer 14 of the circulating outer pipe are sequentially arranged from inside to outside to form a circulating outer pipe insulating section; the one end of circulation outer tube internal tensile layer 14 and circulation outer tube internal and external intermediate layer heat preservation 13 all stretches out outside circulation outer tube external tensile layer 12, both stretch out the end all with the one end welding of inside weld transition pipe 16, outside outer tube weld transition pipe 15 cover is established outside circulation outer tube internal and external intermediate layer heat preservation 13 and inside weld transition pipe 16, 15 one end of outer tube weld transition pipe is welded with circulation outer tube external tensile layer 12 one end, 15 inner walls of outer tube weld transition pipe and circulation outer tube internal and external intermediate layer heat preservation 13 and the welding of inside weld transition pipe 16 outer wall, the outer tube weld transition pipe 15 other end is welded with circulation outer tube heat exchange tube 17 one end, circulation outer tube heat exchange tube 17 other end and circulation outer tube lower part direction head 18 welding.

The circulating inner tube righting support 4 is of a strip structure with two ends bent inwards, the bent ends are welded with the outer wall of the righting snap ring 5, and a small gap is reserved between the circulating inner tube righting support and the tensile layer in the circulating outer tube.

And the upper ends of the heat preservation section of the circulation inner pipe and the heat preservation section of the circulation outer pipe are both in threaded connection with wellhead equipment.

And the two righting snap rings 5 are connected to the heat preservation section of the circulating inner pipe through respective bolts.

The lower part guide head of the circulation outer pipe is of a tubular structure with the lower end blocked, and the other end of the heat exchange pipe of the circulation outer pipe extends into the lower part guide head of the circulation outer pipe and is welded together.

By using CO₂The use method of the double-layer composite continuous pipe for the cyclic geothermal development comprises the following steps of:

the circulating outer pipe assembly and the circulating inner pipe assembly of the double-layer composite continuous pipe are both connected with wellhead equipment, and the double-layer composite continuous pipe is placed into a geothermal well; passing liquid CO through wellhead equipment₂Injecting the liquid CO into the tensile layer 1 of the circulation inner tube from the top of the heat preservation section of the circulation inner tube, passing through a lower joint 6 of the circulation inner tube, a weighted tube 7 of the circulation inner tube, a weighted tube joint 8 of the circulation inner tube, a bottom guide head 9 of the circulation inner tube, a throttling nozzle 10, a throttling nozzle fixing plug 11, and liquid CO₂The liquid CO is sprayed out from the throttling nozzle 10 at the geothermal well heat taking section, the pressure is reduced after the spraying, and simultaneously the liquid CO is heated at the geothermal well high-temperature section₂Quickly gasified to become gas, gaseous CO₂After absorbing the formation heat through heat exchange in the circulating outer tube heat exchange tube 17, the heat returns upwards from the annular space between the circulating inner tube assembly and the circulating outer tube assembly, passes through the internal welding transition tube 16, the outer tube welding transition tube 15 and the circulating outer tube heat preservation section, reaches the well mouth and is discharged to the wellAn oral device.

As shown in FIG. 1, one of the implementations utilizes CO₂The double-layer composite continuous pipe for circulating geothermal development consists of a circulating inner pipe assembly and a circulating outer pipe assembly.

As shown in fig. 2 to 5, the circulating inner tube assembly in this embodiment includes a circulating inner tube tensile layer 1, a circulating inner tube inner temperature layer 2, a circulating inner tube outer heat insulation layer 3, a circulating inner tube righting bracket 4, a righting snap ring 5, a circulating inner tube lower joint 6, a circulating inner tube weighted pipe 7, a circulating inner tube weighted pipe joint 8, a circulating inner tube bottom guide head 9, a throttling nozzle 10, and a throttling nozzle fixing plug 11. Circulation inner tube tensile layer 1, temperature layer 2 in the circulation inner tube, circulation inner tube outer heat preservation 3 sets gradually the constitution circulation inner tube heat preservation section from inside to outside, circulation inner tube heat preservation section both ends are provided with two respectively and right snap ring 5, right snap ring 5 and pass through bolted connection outside circulation inner tube heat preservation section, 4 circulation inner tube righting supports 4 of circulation inner tube evenly distributed in the outer ring of circulation inner tube heat preservation section, 4 both ends of circulation inner tube righting supports are passed through the welding piece welding and are on corresponding righting snap ring 5, ensure that circulation inner tube tensile layer 1 does not take place the skew. The well head is connected to circulation inner tube heat preservation section upper end, circulation inner tube heat preservation section lower extreme and 6 one end of circulation inner tube lower part joint pass through the welding piece welding together, 6 other ends of circulation inner tube lower part joint and circulation inner tube aggravate 7 threaded connection of pipe, the circulation inner tube aggravates 7 other ends of pipe and 9 one ends of circulation inner tube bottom direction head and aggravates 8 threaded connection of pipe joint through the circulation inner tube, 9 other ends of circulation inner tube bottom direction head and the fixed plug 11 threaded connection of throttle mouth, circulation inner tube bottom throttle mouth 10 is in between the fixed plug 11 of circulation inner tube bottom direction head 9 and throttle mouth.

As shown in fig. 6-7, the circulating outer tube assembly in this embodiment mainly comprises an outer tensile layer 12 of the circulating outer tube, an inner and outer interlayer insulating layer 13 of the circulating outer tube, an inner tensile layer 14 of the circulating outer tube, an outer tube welding transition tube 15, an inner welding transition tube 16, a circulating outer tube heat exchange tube 17, and a lower guiding head 18 of the circulating outer tube. The outer tensile layer 12 of the circulating outer pipe, the inner and outer interlayer heat preservation layers 13 of the circulating outer pipe and the inner tensile layer 14 of the circulating outer pipe are sequentially arranged from inside to outside to form a heat preservation section of the circulating outer pipe. The outer tensile layer 12 of the circulating outer pipe is welded with the outer pipe welding transition pipe 15, the inner and outer interlayer heat preservation layer 13 of the circulating outer pipe is located between the inner tensile layer 14 of the circulating outer pipe and the outer tensile layer 12 of the circulating outer pipe, the inner tensile layer 14 of the circulating outer pipe is welded with the inner pipe welding transition pipe 16, the inner pipe welding transition pipe 16 is welded with the outer pipe welding transition pipe 15, the outer pipe welding transition pipe 15 is welded with the circulating outer pipe heat exchange pipe 17, and the circulating outer pipe heat exchange pipe 17 is welded with the lower portion guide head 18 of the circulating outer pipe.

The above-described embodiments are intended to illustrate rather than limit the scope of the invention, and all equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention are intended to be included within the scope of the present system.