Underground steam lifting device for steam injection well and manufacturing process

Abstract

A first heating pipe, a second heating pipe and a third heating pipe are arranged in the device in the radial direction, each heating pipe comprises a wire section and a resistance section, the wire section is used for transmitting electric energy and comprises a high-temperature wire and a first mineral insulating material which are located in a protection pipe, and the resistance section is used for transmitting resistance to the high-temperature wire. The first mineral insulation material is filled in the protection tube and is used for insulation and heat conduction between the high-temperature wire and the tube wall; the resistance section is a heating section and comprises a high-temperature resistance wire located in the protection tube and a first mineral insulation material, and the first mineral insulation material is filled in the protection tube and used for insulation and heat conduction between the high-temperature resistance wire and the tube wall; the high-temperature wire is connected with the high-temperature resistance wire; and the tail ends of the three high-temperature resistance wires are connected to form a three-phase star-shaped balanced heating circuit, so that uniform heating is realized. And the protection tube is arranged, so that higher temperature and higher heating power can be borne, and the high-temperature wire and the high-temperature resistance wire are protected.

Description

Technical Field

[0001] The invention relates to the technical field of heavy oil exploitation by steam injection in oil and gas fields, and in particular to an underground steam extraction device for a steam injection well and a manufacturing process thereof. Background Art

[0002] As the largest heavy oil / high-condensate oil production base in China, Liaohe Oilfield mainly relies on steam injection thermal recovery, with an annual natural gas consumption of 1.52 billion cubic meters and a total carbon emission of 6.15 million tons. It is in urgent need of clean energy substitution to reduce carbon emissions. The effective development of difficult-to-recover reserves such as deep heavy oil / super-heavy oil steam drive, SAGD, shallow high-condensate oil and low-maturity shale oil is an important successor guarantee for Liaohe Oilfield to increase production and stabilize production. The traditional ground-generated steam injection method has large heat loss and low steam dryness in the well, so it is urgent to optimize the energy consumption structure and improve the heating efficiency. Summary of the invention

[0003] The purpose of the present invention is to provide a steam drying device for a steam injection well and a manufacturing process, in which steam is directly injected into a heating device on the ground, and the injected steam is secondary heated in a designed layer section underground to improve the steam dryness underground. The device is applicable to both vertical wells and horizontal wells, and can also be used for underground heating of other injected fluids.

[0004] To achieve the above-mentioned purpose, the technical solution of the present application is: a steam extraction device for an underground steam injection well, wherein a first heating tube, a second heating tube, and a third heating tube are radially arranged inside the device, each heating tube includes a wire segment and a resistance segment, the wire segment is used to transmit electrical energy, and includes a high-temperature wire located in a protective tube, and a first mineral insulating material, the first mineral insulating material is filled in the protective tube for insulation and heat conduction between the high-temperature wire and the pipe wall, and at the same time, the high-temperature wire is wrapped to ensure that the high-temperature wire does not contact the pipe wall; the resistance segment is a heating segment, including a high-temperature resistance wire located in the protective tube, and a first mineral insulating material, the first mineral insulating material is filled in the protective tube for insulation and heat conduction between the high-temperature resistance wire and the pipe wall, and at the same time, the high-temperature resistance wire is wrapped to ensure that the high-temperature resistance wire does not contact the pipe wall; the high-temperature wire and the high-temperature resistance wire are connected by a connector; the ends of the three high-temperature resistance wires are connected to form a three-phase star-shaped balanced heating circuit to achieve uniform heating.

[0005] Furthermore, the outside of the device is a high temperature resistant continuous oil pipe, and one or more fixing frames are arranged inside the high temperature resistant continuous oil pipe for fixing the positions of the first heating pipe, the second heating pipe and the third heating pipe in the high temperature resistant continuous oil pipe.

[0006] Furthermore, a second mineral insulating material is filled between the high temperature resistant coiled oil pipe and the three heating pipes.

[0007] Furthermore, the high temperature resistant continuous oil pipe is connected to a high temperature sealing cover, and the high temperature sealing cover is used to seal the first heating pipe, the second heating pipe, and the third heating pipe at the wellhead end.

[0008] Furthermore, the ends of the three high-temperature resistance wires are connected via a high-temperature connector.

[0009] Furthermore, the ends of the three heating tubes are connected and fixed through a high-temperature connecting frame.

[0010] Furthermore, the high-temperature conductor material is a copper wire core, the high-temperature resistant continuous oil pipe and the protective pipe are high-temperature resistant stainless steel, the high-temperature sealing cover, the fixing frame, the connector, the high-temperature connecting head, and the high-temperature connecting frame are high-temperature resistant alloy steel, and the high-temperature resistance wire is made of a high-temperature resistant resistance material nickel-chromium alloy.

[0011] Furthermore, the device is lowered into a horizontal well or a vertical well through a thermal recovery steam injection wellhead. After reaching the target layer, a wellhead sealer is installed at the wellhead, and the conductor segment is connected to a high-pressure ground power regulator. The working state of the heating segment is controlled at the ground end to adjust the heating power. During steam injection, steam is injected into the well through an insulated pipe, and the steam flows downward along the insulated pipe, and is insulated using a thermosensitive sealer. After the steam flows through the heating segment, the ground end controls the heating segment to start working, and the injected steam is continuously heated along the resistance segment. After the steam dryness is increased, it flows out from the outlet at the lower end of the insulated pipe and is injected into the designed layer segment.

[0012] The present application also provides a manufacturing process for a steam extraction device for a steam injection well, which adopts a continuous welding powder filling method and specifically includes:

[0013] First, the high-temperature conductor and the high-temperature resistance wire are connected through a connector, welded and fixed, and the weld is shaped and punched flat; then the metal strip for making the protective tube is continuously longitudinally wrapped through a group of forming rollers to form a cylindrical protective tube, and the edge of the metal strip is continuously longitudinally welded by argon arc welding under argon protection. The welded high-temperature conductor and high-temperature resistance wire enter the protective tube through a first fixed tube, and the outlet of the first fixed tube is set on one side of the metal strip. The magnetically selected first mineral insulating material powder is sent from the hopper through the first fixed tube into the protective tube and vibrated, and then continuously rolled or cold drawn and annealed to complete the production of the heating tube.

[0014] Furthermore, the above process also includes connecting the ends of the three heating tubes to a high-temperature connecting frame, in which the high-temperature resistance wires are connected and fixed to each other through a high-temperature connecting head; the metal strip for making the high-temperature resistant continuous oil pipe is continuously longitudinally wrapped by a group of forming rollers to form a cylindrical high-temperature resistant continuous oil pipe, the edge of the metal strip is continuously longitudinally welded by argon arc welding under argon protection, the three connected heating tubes enter the high-temperature resistant continuous oil pipe through a second fixed pipe, the outlet of the second fixed pipe is set on one side of the metal strip, and the magnetically selected second mineral insulating material powder is sent from the hopper through the second fixed pipe into the high-temperature continuous oil pipe and vibrated, and then continuously rolled or cold drawn and annealed to form a finished product.

[0015] Due to the adoption of the above technical scheme, the present invention can achieve the following technical effects: The present invention provides a steam-injection well underground steam drying device and manufacturing process, which can reheat underground steam, increase the steam dryness and directly inject it into the designed layer, significantly improve the heating efficiency, and have great applicability to steam throughput, steam drive, SAGD wells, especially deep wells, and can be promoted and applied on a large scale. By rationally utilizing the green electricity + grid electricity working system, the electrification rate of heavy oil thermal recovery development can be comprehensively improved to achieve the purpose of clean energy substitution and carbon emission reduction. The provision of a protective tube can withstand higher temperatures and greater heating power, and protect high-temperature conductors and high-temperature resistance wires. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0017] Figure 1 A cross-sectional view of a steam extraction device downhole in a steam injection well;

[0018] Figure 2 This is an end view of a steam extraction device downhole in a steam injection well;

[0019] Figure 3 This is a usage status diagram of a steam extraction device downhole in a steam injection well;

[0020] Explanation of the serial numbers in the figure: 1-first heating tube; 2-second heating tube; 3-third heating tube; 4-high-temperature conductor; 5-protective tube; 6-high-temperature sealing cover; 7-first mineral insulating material; 8-fixed frame; 9-high-temperature resistant continuous oil pipe; 10-connector; 11-high-temperature resistance wire; 12-second mineral insulating material; 13-high-temperature connector; 14-high-temperature connecting frame; 2-1-high-pressure ground power regulator; 2-2-conductor section; 2-3-wellhead sealer; 2-4-thermal recovery steam injection wellhead; 2-5-insulated tube; 2-6-thermal sensitive packer; 2-7-resistance section; 2-8-designed layer section. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] Example 1

[0023] like Figure 1-2 As shown, this embodiment provides a steam extraction device for a steam injection well. The injected steam is heated for a second time underground. After further improving the steam dryness, the steam is directly injected into the designed layer. The electric heating efficiency is maximized, and the development problems of SAGD and steam drive wells in the deep and medium layers are effectively solved. In order to meet the requirements of long-term stable extraction of underground steam, three heating tubes are radially arranged inside the device: the first heating tube 1, the second heating tube 2, and the third heating tube 3. Each heating tube includes a wire segment and a resistance segment. The wire segment is used to transmit electric energy, including a high-temperature wire 4 and a first mineral insulating material 7 located inside the protective tube 5; the resistance segment is a heating segment, including a high-temperature resistance wire 11 and a first mineral insulating material 7 located inside the protective tube 5. The first mineral insulating material 7 is filled inside the protective tube 5 for insulation and heat conduction, and also ensures that the high-temperature wire 4 and the high-temperature resistance wire 11 do not contact the pipe wall. The ends of the three heating tubes are connected and fixed by a high-temperature connecting frame 14, and the ends of the three high-temperature resistance wires inside are also connected to each other through a high-temperature connector 13, forming a three-phase star-shaped balanced heating circuit to achieve uniform heating.

[0024] The exterior of the present invention is a high temperature resistant coiled tubing 9, and a fixing frame 8 is located inside the high temperature resistant coiled tubing 9, which may be one or more and is used to fix the positions of the first heating tube 1, the second heating tube 2 and the third heating tube 3 in the high temperature resistant coiled tubing 9. A second mineral insulating material 12 is filled between the high temperature resistant coiled tubing 9 and the three heating tubes, which is used for insulation and heat conduction between the three heating tubes and the wall of the high temperature resistant coiled tubing, and also prevents them from contacting the wall of the coiled tubing, so as to ensure the long-term stable operation of the device.

[0025] To ensure long-term high-temperature operation underground, all materials of the steam drying device of the present invention need to meet certain temperature resistance indicators. The high-temperature conductor 4 is made of copper wire core, the high-temperature resistant continuous oil pipe 9 and the protective pipe 5 are made of high-temperature resistant stainless steel, the high-temperature sealing cover 6 and the fixing frame 8; the connector 10, the high-temperature connector 13, and the high-temperature connecting frame 14 are made of high-temperature resistant alloy steel, and the high-temperature resistance wire 11 is made of high-temperature resistant resistance material nickel-chromium alloy. The first mineral insulating material 7 and the second mineral insulating material 12 are preferably used for insulation and heat conduction.

[0026] The above device can be used for vertical wells and horizontal wells, and here we mainly explain vertical wells. It is lowered into the well through the thermal recovery steam injection wellhead 2-4. After reaching the target layer, the device is fixed at the wellhead through the wellhead sealer 2-3, and the wire segment is connected to the high-pressure ground power regulator 2-1. The working state of the heating section is controlled at the ground end to adjust the heating power. During steam injection, steam is injected into the well through the insulation pipe 2-5. At the designed injection flow rate, the steam flows downward along the insulation pipe 2-5 and is insulated by the thermosensitive packer 2-6. After the steam flows through the heating section, the ground end controls the heating section to start working, and the injected steam passes through the lower resistance section 2-7 of the device and is continuously heated along the way. After the steam dryness is increased, it flows out from the outlet at the lower end of the insulation pipe and is injected into the designed layer.

[0027] The present invention is a continuous tubular steam extraction device, the outer tube of which is a continuous oil pipe. Through the optimization of materials and process structures, it can work continuously for a long time in an environment of high-temperature steam corrosion and scouring in a steam injection pipe column. It has low requirements on the downhole space, casing size and well conditions of the development well, and can be widely promoted and applied in the later stage.

[0028] Example 2

[0029] The present embodiment provides a manufacturing process for an underground steam extraction device for a steam injection well: a continuous welding powder filling method is adopted. First, the high-temperature conductor 4 and the high-temperature resistance wire 11 are connected through a connector 13, and then welded and fixed, and the weld is shaped and punched flat to avoid burrs. The metal strip for making the protective tube 5 is continuously longitudinally wrapped through a group of forming rollers to form a cylindrical protective tube 5. The edge of the metal strip is continuously longitudinally welded by argon arc welding under the protection of argon gas. The welded high-temperature conductor 4 and the high-temperature resistance wire 11 enter the protective tube 5 through a first fixed tube. The outlet of the first fixed tube is set on one side of the metal strip. The first mineral insulating material powder after magnetic separation is sent from the hopper through the first fixed tube into the protective tube 5 and vibrated, and then through continuous rolling or cold drawing and annealing, the heating tube is completed.

[0030] Similarly, the ends of the three heating tubes are connected to the high-temperature connecting frame 14, and the high-temperature resistance wires 11 therein are connected and fixed to each other through the high-temperature connecting head 13. The metal strip for making the high-temperature continuous oil pipe 9 is continuously longitudinally wrapped by a group of forming rollers to form a cylindrical high-temperature continuous oil pipe 9. The edge of the metal strip is continuously longitudinally welded by argon arc welding under argon protection. The three connected heating tubes enter the high-temperature continuous oil pipe 9 through the second fixed pipe. The outlet of the second fixed pipe is set on one side of the metal strip. The second mineral insulating material powder after magnetic separation is sent from the hopper through the second fixed pipe into the high-temperature continuous oil pipe and vibrated, and then it is continuously rolled or cold drawn and annealed to obtain the finished product. The advantages of the continuous welding powder filling method are that the protective tube 5 and the high-temperature continuous oil pipe 9 are formed by metal strip welding, the manufacturing length is not limited, the production line has a high degree of automation, low labor intensity, and a short production cycle.

[0031] The present invention is aimed at medium-deep steam drive / SAGD development wells and steam huff-and-puff wells. Through power grid transformation, the existing green electricity in the oil field can be fully utilized to power the electric heater, thereby realizing green electricity consumption. By rationally utilizing the green electricity + grid electricity working system to power the electric heater, the electrification rate of heavy oil development can be comprehensively improved, thereby achieving the purpose of clean energy substitution and carbon emission reduction.

[0032] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0033] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A steam extraction device for a steam injection well, characterized in that: The device is radially provided with a first heating tube, a second heating tube and a third heating tube. Each heating tube includes a conductor segment and a resistance segment. The conductor segment is used to transmit electric energy and includes a high-temperature conductor located in a protective tube and a first mineral insulating material. The first mineral insulating material is filled in the protective tube for insulation and heat conduction between the high-temperature conductor and the tube wall, and at the same time, the high-temperature conductor is wrapped to ensure that the high-temperature conductor does not contact the tube wall. The resistance segment is a heating segment and includes a high-temperature resistance wire located in the protective tube and a first mineral insulating material. The first mineral insulating material is filled in the protective tube for insulation and heat conduction between the high-temperature resistance wire and the tube wall, and at the same time, the high-temperature resistance wire is wrapped to ensure that the high-temperature resistance wire does not contact the tube wall. The high-temperature conductor and the high-temperature resistance wire are connected by a connector. The ends of the three high-temperature resistance wires are connected to form a three-phase star-shaped balanced heating circuit to achieve uniform heating.

2. A steam extraction device for a steam injection well according to claim 1, characterized in that: The outside of the device is a high temperature resistant coiled oil pipe, and one or more fixing frames are arranged inside the high temperature resistant coiled oil pipe for fixing the positions of the first heating pipe, the second heating pipe and the third heating pipe in the high temperature resistant coiled oil pipe.

3. A steam extraction device for a steam injection well according to claim 2, characterized in that: A second mineral insulating material is filled between the high temperature resistant coiled oil pipe and the three heating pipes.

4. A steam extraction device for a steam injection well according to claim 2, characterized in that: The high temperature resistant coiled tubing is connected to a high temperature sealing cover, and the high temperature sealing cover is used to seal the first heating tube, the second heating tube, and the third heating tube at the wellhead end.

5. The downhole steam stripping device for a steam injection well according to claim 1, characterized in that: The ends of the three high-temperature resistance wires are connected via a high-temperature connector.

6. The downhole steam stripping device for a steam injection well according to claim 1, characterized in that: The ends of the three heating tubes are connected and fixed through a high-temperature connecting frame.

7. The downhole steam stripping device for a steam injection well according to claim 1, characterized in that: The high-temperature conductor material is a copper wire core, the high-temperature resistant continuous oil pipe and the protective pipe are high-temperature resistant stainless steel, the high-temperature sealing cover, the fixing frame, the connector, the high-temperature connecting head and the high-temperature connecting frame are high-temperature resistant alloy steel, and the high-temperature resistance wire is made of a high-temperature resistant resistance material nickel-chromium alloy.

8. The downhole steam stripping device for a steam injection well according to claim 1, characterized in that: The device is lowered into a horizontal well or a vertical well through the thermal recovery steam injection wellhead. After reaching the target layer, a wellhead sealer is installed at the wellhead, and the conductor segment is connected to a high-pressure ground power regulator. The working state of the heating segment is controlled at the ground end to adjust the heating power. During steam injection, steam is injected into the well through an insulated pipe, and the steam flows downward along the insulated pipe, and is insulated by a thermosensitive packer. After the steam flows through the heating segment, the ground end controls the heating segment to start working, and the injected steam is continuously heated along the resistance segment. After the steam dryness is increased, it flows out from the outlet at the lower end of the insulated pipe and is injected into the designed layer segment.

9. A manufacturing process for a steam extraction device for a steam injection well, characterized in that: A continuous welding powder filling method is adopted, which specifically includes: first, the high-temperature conductor and the high-temperature resistance wire are connected through a connector, and then welded and fixed, and the weld is shaped and punched flat; then the metal strip for making the protective tube is continuously longitudinally wrapped through a group of forming rollers to form a cylindrical protective tube, and the edge of the metal strip is continuously longitudinally welded by argon arc welding under argon protection. The welded high-temperature conductor and high-temperature resistance wire enter the protective tube through a first fixed tube, and the outlet of the first fixed tube is set on one side of the metal strip. The magnetically selected first mineral insulating material powder is sent from the hopper through the first fixed tube into the protective tube and vibrated, and then continuously rolled or cold drawn and annealed to complete the production of the heating tube.

10. A manufacturing process for a steam extraction device for a steam injection well according to claim 9, characterized in that: The above process also includes connecting the ends of the three heating tubes to a high-temperature connecting frame, in which the high-temperature resistance wires are connected and fixed to each other through a high-temperature connecting head; the metal strip for making the high-temperature resistant continuous oil pipe is continuously longitudinally wrapped by a group of forming rollers to form a cylindrical high-temperature resistant continuous oil pipe, the edge of the metal strip is continuously longitudinally welded by argon arc welding under argon protection, the three connected heating tubes enter the high-temperature resistant continuous oil pipe through a second fixed pipe, the outlet of the second fixed pipe is set on one side of the metal strip, the second mineral insulating material powder that has been magnetically selected is sent from the hopper through the second fixed pipe into the high-temperature resistant continuous oil pipe and vibrated, and then continuously rolled or cold drawn and annealed to form a finished product.

Images