CN106168119B - Downhole Electric Heating Horizontal Production Well String Structure - Google Patents

Abstract

The embodiment of the application provides a downhole electrical heating horizontal production well tubular column structure, which comprises a casing, a horizontal liner tube connected with the lower end of the casing, and an oil tube positioned in a cavity enclosed by the casing and the horizontal liner tube, wherein the oil tube comprises a first metal oil tube and a second metal oil tube which are used for forming an electromagnetic wave energy transmission channel, the second metal oil tube is sleeved on the metal oil tube, and the cavity between the second metal oil tube and the metal oil tube is hermetically filled with an insulating material; the sleeve and the horizontal liner tube are isolated in an insulating way, the horizontal liner tube is divided into two parts which are isolated in an insulating way along the radial direction of the horizontal liner tube to be used as two arms of the radio frequency antenna, and the first metal oil tube and the second metal oil tube are respectively coupled with the two arms of the radio frequency antenna correspondingly; the structure further includes: the coiled tubing is used for forming an oil-gas transmission channel and is positioned in a cavity defined by the casing and the horizontal liner tube; a hot fluid injection pipe is arranged in the coiled tubing. The embodiment of the application can be suitable for the cooperative development of electromagnetic waves and hot fluid.

Description

Downhole Electric Heating Horizontal Production Well String Structure

technical field

The present application relates to oil production equipment in an oil field, in particular to a downhole electric heating horizontal production well string structure.

Background technique

At present, for the development of horizontal wells in heavy oil reservoirs, horizontal wells are mainly used for steam huff and puff, steam flooding and steam assisted gravity drainage (SAGD). However, due to the high energy consumption of steam injection, large carbon emissions, and high energy consumption, it is necessary to develop new heating technologies for heavy oil recovery. At present, technologies such as electric heating for heavy oil recovery have emerged, and may become one of the most potential development technologies for heavy oil development in the future.

Theoretical research shows that the combination of electromagnetic wave heating generated by magnetic dipoles and the current steam injection or light hydrocarbon solvent injection can effectively compensate for the small radius of pure electromagnetic wave heating and the excessive energy attenuation rate of electromagnetic waves in oil layers. At the same time, it can make up for the problem of low steam dryness in the bottom hole of simple steam injection, and can also make up for the problem of low solvent diffusion rate in the bottom hole of simple light hydrocarbon solvent injection. Heating with steam/low-temperature light hydrocarbon solvent can effectively increase the dryness of steam at the bottom of the well or the temperature of light hydrocarbon solvent, and greatly improve the oil displacement effect and diffusion rate of the injected fluid into the oil layer, thereby increasing the production of production wells.

In the process of realizing the present application, the inventors of the present application found that the synergistic development of the above-mentioned electromagnetic wave and steam injection, injection of light hydrocarbon solvent, water, etc. is still in the stage of theoretical research and has not yet been applied in practice. The reason for the lack of practical application is that the existing horizontal injection well string structure used in the development of heavy oil is usually designed for a single heating method, so it cannot be applied to the coordinated development of electromagnetic waves and steam injection, light hydrocarbon solvent injection, and water injection. Therefore, there is an urgent need for a string structure that adapts to the coordinated development of electromagnetic waves and steam injection, light hydrocarbon solvent injection, and water injection.

Contents of the invention

The purpose of the embodiments of the present application is to provide a downhole electric heating horizontal production well string structure suitable for the coordinated development of electromagnetic waves and steam injection, light hydrocarbon solvent injection, water injection, etc.

In order to achieve the above purpose, the embodiment of the present application provides a downhole electric heating horizontal production well string structure, including a casing, a horizontal liner connected to the lower end of the casing, and a horizontal liner between the casing and the horizontal Tubing in a cavity enclosed by a liner, where:

The oil pipe includes a first metal oil pipe and a second metal oil pipe for forming an electromagnetic wave energy transmission channel, the second metal oil pipe is sleeved on the first metal oil pipe, and the second metal oil pipe and the first metal oil pipe The cavity between them is sealed and filled with insulating material;

The casing and the horizontal liner are insulated and isolated, and the horizontal liner is divided into two parts which are insulated and isolated from each other along its radial direction, and the two parts form two arms of the radio frequency antenna, and the first A metal oil pipe and the second metal oil pipe are respectively coupled with the two arms of the radio frequency antenna;

The well string structure also includes:

Coiled tubing for forming oil and gas transmission passages, said coiled tubing being located in a cavity surrounded by said casing and said horizontal liner;

A thermal fluid injection pipe is installed in the coiled tubing.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the oil pipe also includes a third metal oil pipe for isolating the electromagnetic wave energy transmission channel from the oil layer fluid, and the third metal oil pipe is sleeved on the two on the metal tubing.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the first metal oil pipe and the second metal oil pipe are respectively connected to the two arms of the radio frequency antenna through corresponding radio frequency antenna connectors.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the lower end of the third metal oil pipe is closed, and the lower ends of the first metal oil pipe and the lower end of the second metal oil pipe are open and located in the first metal oil pipe. Three metal oil pipes, so that the cavity between the third metal oil pipe and the second metal oil pipe communicates with the inner cavity of the first metal oil pipe to form a cooling material circulation channel for cooling the electromagnetic wave energy transfer channel.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the third metal oil pipe is installed with a primary shield for shielding electromagnetic waves on the third metal oil pipe on the outer surface inside the horizontal liner element.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the third metal oil pipe is equipped with a secondary shielding element on the outer surface inside the casing.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the end of the electromagnetic wave energy transmission channel is provided with a guide head.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the guide head is sealed and connected to the electromagnetic wave energy transmission channel through a safety valve.

In the downhole electric heating horizontal production well tubular string structure of the embodiment of the present application, the first centralizer for preventing mutual friction between the guiding head and the horizontal liner is installed on the guiding head.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the third metal oil pipe is fixed on the inner wall of the horizontal liner through the oil pipe anchor.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the third metal oil pipe is installed on the outer surface inside the horizontal liner to prevent the third metal oil pipe from interacting with the horizontal liner. Friction of the second centralizer.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the hot fluid injection pipe is provided with evenly distributed fluid injection holes on the part inside the horizontal liner.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the outer surface of the third metal oil pipe is covered with an anti-corrosion layer.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the insulating material filled in the cavity between the second metal oil pipe and the first metal oil pipe includes high-pressure nitrogen.

In the downhole electric heating horizontal production well tubular string structure of the embodiment of the present application, the two arms of the radio frequency antenna are equal in length.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the horizontal liner is connected to the lower end of the casing through a liner hanger, and the joint is provided to make the casing and the horizontal liner Insulating parts that are insulated from each other.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the liner hanger includes a sealing packer with a matching expansion joint.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the material of the first metal oil pipe and the second metal oil pipe is brass, and the material of the third metal oil pipe is stainless steel.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the material of the centralizer includes Teflon.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the oil pipe includes a first metal oil pipe and a second metal oil pipe, the second metal oil pipe is sleeved on a metal oil pipe, and the second metal oil pipe and a metal oil pipe The cavity is sealed and filled with insulating material, so that the first metal oil pipe and the second metal oil pipe form a structure similar to a coaxial cable, and this structure forms an electromagnetic wave energy transmission channel. The casing and the horizontal liner in the embodiment of the present application are insulated and isolated, and the horizontal liner is divided into two parts that are insulated and isolated from each other along its radial direction, and the two parts form the two arms of the radio frequency antenna. The first metal oil pipe, the second The two metal oil pipes are respectively coupled with the two arms of the radio frequency antenna, so that the electromagnetic wave energy transmitted through the electromagnetic wave energy transmission channel can act on the reservoir fluid through the radio frequency antenna to heat it. In addition, the well string structure of the embodiment of the present application also includes coiled tubing for forming oil and gas transmission channels, and the coiled tubing is located in the cavity surrounded by the casing and the horizontal liner; thermal fluid injection is installed in the coiled tubing Tube. Therefore, the well string structure of the embodiment of the present application can be applied to electromagnetic wave and steam injection, injection of light hydrocarbon solvent, water and other foreign-related collaborative development, so that the heating rate and oil recovery rate of the bottom hole can be greatly improved, and the oil recovery rate of thermal recovery and injection can be improved. efficiency.

Description of drawings

The drawings described here are used to provide further understanding of the embodiments of the present application, constitute a part of the embodiments of the present application, and do not limit the embodiments of the present application. In the attached picture:

Fig. 1 is a schematic cross-sectional front view of a downhole electrically heated horizontal production well string structure according to an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solutions, and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the schematic embodiments and descriptions of the embodiments of the present application are used to explain the embodiments of the present application, but are not intended to limit the embodiments of the present application.

The specific implementation manners of the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, the downhole electric heating horizontal production well string structure of the embodiment of the present application includes a thermal recovery wellhead 1, a casing 20 connected to the thermal recovery wellhead 1, and a horizontal casing connected to the lower end of the casing 20. The liner, and the oil pipe located in the cavity surrounded by the casing 20 and the horizontal liner. The downhole electric heating horizontal production well string structure of the embodiment of the present application also includes: a coiled tubing 70 used to form oil and gas transmission channels, and the coiled tubing 70 is located in the cavity surrounded by the casing 20 and the horizontal liner; A hot fluid injection pipe 71 is installed in the oil pipe 70. In a specific implementation of the present application, the hot fluid injection pipe 71 may be, for example, a gas lift steam injection pipe.

In the embodiment of the present application, the oil pipe includes a first metal oil pipe 62 and a second metal oil pipe 61 for forming an electromagnetic wave energy transmission channel, the second metal oil pipe 61 is sleeved on the first metal oil pipe 62, and the The cavity between the second metal oil pipe 61 and the first metal oil pipe 62 is sealed and filled with insulating materials, which can prevent the annular space surrounded by the first metal oil pipe 62 and the second metal oil pipe 61 from being generated. electric field. In a specific embodiment of the present application, the insulating material filled in the cavity between the second metal oil pipe 61 and the first metal oil pipe 62 may be, for example, high-pressure nitrogen.

In the embodiment of the present application, the casing 20 is insulated from the horizontal liner, and the horizontal liner is divided into two parts in the radial direction by an insulating member 41 , which are insulated from each other. The two parts form the two arms (ie 30 and 31) of the radio frequency antenna, and the first metal oil pipe 62 and the second metal oil pipe 61 are correspondingly coupled with the two arms of the radio frequency antenna. In a specific embodiment of the present application, the lengths of the two arms of the radio frequency antenna are equal, and the first metal oil pipe 62 and the second metal oil pipe 61 are respectively connected to the radio frequency antenna through corresponding radio frequency antenna connectors. The two arms are connected. The radio frequency antenna connector is used to conduct the radio frequency current transmitted by the electromagnetic wave energy transmission channel to the two arms of the radio frequency antenna, so as to generate high frequency electromagnetic waves to act on the oil layer fluid.

In another embodiment of the present application, the oil pipe may further include a third metal oil pipe 60 for isolating the electromagnetic wave energy transmission channel from the oil reservoir fluid, and the third metal oil pipe 60 is sleeved on the second metal oil pipe 61 superior.

In another embodiment of the present application, the lower end of the third metal oil pipe 60 is sealed, and the lower ends of the first metal oil pipe 62 and the lower ends of the second metal oil pipe 61 are open and located in the third metal oil pipe. 60, so that the cavity between the third metal oil pipe 60 and the second metal oil pipe 61 communicates with the inner cavity of the first metal oil pipe 62 to form a cooling material circulation channel for cooling the The above-mentioned electromagnetic wave energy transmission channel. In a specific embodiment of the present application, the cooling material may flow in from the cavity between the third metal oil pipe 60 and the second metal oil pipe 61, and then flow out from the inner cavity of the first metal oil pipe 62, Therefore, it plays a role of cooling the electromagnetic wave energy transmission channel during the heating process.

In another embodiment of the present application, the third metal oil pipe 60 is installed on the outer surface of the horizontal liner with a primary shielding element 90 for shielding electromagnetic waves on the third metal oil pipe 60 (that is, to avoid Electromagnetic waves are generated on the third metal oil pipe 60 due to radiation along the way). In a specific embodiment of the present application, the primary shielding element 90 may be composed of several ferromagnetic rings.

In another embodiment of the present application, in order to further improve the electromagnetic wave absorption effect, the third metal oil pipe 60 may be further equipped with a secondary shielding element 91 on the outer surface inside the casing. In a specific embodiment of the present application, the secondary shielding element 91 may also be composed of several ferromagnetic rings.

In another embodiment of the present application, a guiding head 65 is provided at the end of the electromagnetic wave energy transmission channel. The guide head 65 and the electromagnetic wave energy transmission channel can be sealed and connected through a safety valve 64. Since the safety valve 64 can perform high-pressure sealing on the electromagnetic wave energy transmission channel, the first electromagnetic wave energy transmission channel can be sealed under high temperature and high pressure conditions. The two metal oil pipes 61 can maintain a sealed connection with the radio frequency antenna connector. In order to cooperate with the above-mentioned cooling of the electromagnetic wave energy transmission channel, a one-way valve flow channel is provided inside the safety valve 64 , and the one-way valve flow channel is used as a part of the cooling material circulation channel to facilitate the circulation of the cooling material. Wherein, a sealing ring 63 is provided at the connection between the third metal oil pipe 60 and the safety valve 64 .

In another embodiment of the present application, in order to prevent the components from rubbing against each other, the guide head 65 is equipped with a centralizer 66 for preventing the guide head 65 from rubbing against the horizontal liner; the third metal oil pipe 60 A centralizer 66 for preventing the third metal oil pipe 60 from rubbing against the horizontal liner is installed on the outer surface inside the horizontal liner. Wherein, the centralizers 66 may be in a ring structure and arranged at equal intervals.

In another embodiment of the present application, the third metal oil pipe 60 may be fixed on the inner wall of the horizontal liner through an oil pipe anchor 8 . At the same time, the oil pipe anchor 8 can also play a role of limiting the electromagnetic wave energy transmission channel.

In another embodiment of the present application, the coiled tubing 70 can adopt a variable diameter setting. At the main body position of the electromagnetic wave energy delivery tube, the diameter of the coiled tubing is 2 to 5 inches, and at the position of the guide head 65 of the electromagnetic wave energy delivery tube , the diameter of the coiled tubing is 5-7 inches. The diameter of the hot fluid injection pipe 71 is 1-1.5 inches, and the distance between the end of the hot fluid injection pipe 71 and the outlet of the coiled tubing 70 is 3-10 meters. In another embodiment of the present application, an anti-corrosion layer is laid on the outer surface of the third metal oil pipe 60 to prevent or reduce corrosion of the third metal oil pipe 60 by the oil layer fluid and injection fluid.

In another embodiment of the present application, the horizontal liner is connected to the lower end of the casing 20 through a liner hanger 21, and the connection is provided to insulate the casing from the horizontal liner. The insulating part 40. In a specific embodiment of the present application, the liner hanger 21 may be a sealing packer with a matching expansion joint. This kind of sealing packer with matching expansion sub-joint can withstand the stretching caused by the thermal expansion of the liner in the horizontal section at high temperature or the contraction after cooling down, and has the function of sealing under high temperature and high pressure.

In another embodiment of the present application, the material of the first metal oil pipe and the second metal oil pipe may be brass, and the material of the third metal oil pipe may be stainless steel.

In another embodiment of the present application, the material of the centralizer includes Teflon.

In the downhole electric heating horizontal production well string structure of the embodiment of the present application, the oil pipe includes a first metal oil pipe and a second metal oil pipe, the second metal oil pipe is sleeved on a metal oil pipe, and the second metal oil pipe and a metal oil pipe The cavity is sealed and filled with insulating material, so that the first metal oil pipe and the second metal oil pipe form a structure similar to a coaxial cable, and this structure forms an electromagnetic wave energy transmission channel. The casing and the horizontal liner in the embodiment of the present application are insulated and isolated, and the horizontal liner is divided into two parts that are insulated and isolated from each other along its radial direction, and the two parts form the two arms of the radio frequency antenna. The first metal oil pipe, the second The two metal oil pipes are respectively coupled with the two arms of the radio frequency antenna, so that the electromagnetic wave energy transmitted through the electromagnetic wave energy transmission channel can act on the reservoir fluid through the radio frequency antenna to heat it. In addition, the well string structure of the embodiment of the present application also includes coiled tubing for forming oil and gas transmission channels, and the coiled tubing is located in the cavity surrounded by the casing and the horizontal liner; thermal fluid injection is installed in the coiled tubing Tube. Therefore, the well string structure of the embodiment of the present application can be applied to electromagnetic wave and steam injection, injection of light hydrocarbon solvent, water and other foreign-related collaborative development, so that the heating rate and oil recovery rate of the bottom hole can be greatly improved, and the oil recovery rate of thermal recovery and injection can be improved. efficiency.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above descriptions are only specific embodiments of the embodiments of the present application, and are not intended to limit this application. Within the protection scope of the application, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims (19)

1. A downhole electric heating horizontal production well string structure, comprising a casing, a horizontal liner connected to the lower end of the casing, and a casing located in a cavity surrounded by the casing and the horizontal liner Oil pipe, characterized in that: The oil pipe includes a first metal oil pipe and a second metal oil pipe for forming an electromagnetic wave energy transmission channel, the second metal oil pipe is sleeved on the first metal oil pipe, and the second metal oil pipe and the first metal oil pipe The cavity between them is sealed and filled with insulating material; The casing and the horizontal liner are insulated and isolated, and the horizontal liner is divided into two parts which are insulated and isolated from each other along its radial direction, and the two parts form two arms of the radio frequency antenna, and the first A metal oil pipe and the second metal oil pipe are respectively coupled with the two arms of the radio frequency antenna; The well string structure also includes: Coiled tubing for forming oil and gas transmission passages, said coiled tubing being located in a cavity surrounded by said casing and said horizontal liner; A thermal fluid injection pipe is installed in the coiled tubing. 2. The downhole electric heating horizontal production well tubing string structure according to claim 1, characterized in that the tubing further comprises a third metal tubing for isolating the electromagnetic wave energy transmission channel from the reservoir fluid, and the first The three-metal oil pipe is sleeved on the two-metal oil pipe. 3. The downhole electric heating horizontal production well string structure according to claim 1, characterized in that the first metal oil pipe and the second metal oil pipe are respectively connected to the radio frequency antenna through corresponding radio frequency antenna connectors The two arms are connected. 4. The downhole electric heating horizontal production well string structure according to claim 2, characterized in that the lower end of the third metal oil pipe is airtight, the lower end of the first metal oil pipe and the lower end of the second metal oil pipe Both are open and located in the third metal oil pipe, so that the cavity between the third metal oil pipe and the second metal oil pipe communicates with the inner cavity of the first metal oil pipe to form a cooling material circulation channel , for cooling the electromagnetic wave energy transmission channel. 5. The downhole electric heating horizontal production well string structure according to claim 2, characterized in that, the third metal tubing is installed on the outer surface inside the horizontal liner to shield the third metal tubing. Primary shielding element for electromagnetic waves on the tubing. 6 . The downhole electric heating horizontal production well string structure according to claim 2 , characterized in that, the third metal tubing is provided with a secondary shielding element on the outer surface inside the casing. 7 . 7. The downhole electric heating horizontal production well string structure according to claim 1, characterized in that a guide head is arranged at the end of the electromagnetic wave energy transmission channel. 8 . The downhole electric heating horizontal production well string structure according to claim 7 , wherein the guide head is sealed and connected to the electromagnetic wave energy transmission channel through a safety valve. 9 . The downhole electrically heated horizontal production well string structure according to claim 7 , wherein a first centralizer for preventing mutual friction between the guide head and the horizontal liner is installed on the guide head. 10 . 10 . The downhole electrically heated horizontal production well string structure according to claim 2 , wherein the third metal tubing is fixed on the inner wall of the horizontal liner through tubing anchors. 11 . 11. The downhole electric heating horizontal production well string structure according to claim 2, characterized in that, the third metal tubing is installed on the outer surface inside the horizontal liner to prevent the third metal The second centralizer for friction between the oil pipe and the horizontal liner. 12. The downhole electrically heated horizontal production well string structure according to claim 1, characterized in that the hot fluid injection pipe is provided with evenly distributed fluid injection holes on the part inside the horizontal liner. 13. The downhole electric heating horizontal production well string structure according to claim 2, characterized in that an anti-corrosion layer is laid on the outer surface of the third metal tubing. 14. The downhole electric heating horizontal production well string structure according to claim 1, characterized in that the insulating material filling the cavity between the second metal oil pipe and the first metal oil pipe includes high-pressure nitrogen. 15. The downhole electrically heated horizontal production well tubular string structure according to claim 1, wherein the lengths of the two arms of the radio frequency antenna are equal. 16. The downhole electric heating horizontal production well string structure according to claim 1, characterized in that the horizontal liner is connected to the lower end of the casing through a liner hanger, and the connection is provided to make the An insulating part that is insulated and isolated between the casing and the horizontal liner. 17. The downhole electrically heated horizontal production well string structure according to claim 16, wherein the liner hanger comprises a sealing packer with a matching expansion joint. 18. The downhole electric heating horizontal production well string structure according to claim 2, characterized in that, the material of the first metal oil pipe and the second metal oil pipe is brass, and the material of the third metal oil pipe is brass. For stainless steel. 19. The downhole electric heating horizontal production well string structure according to claim 9 or 11, characterized in that the material of the centralizer includes Teflon.