JOINTED PIPE INCLUDING AN RF HEATING SYSTEM

A subterranean radio frequency (RF) heating system includes a first tubular member having a first end, a second end, and an inner surface. A second tubular member is arranged radially inwardly of the inner surface of the first tubular member. The second tubular member includes a first end portion, a second end portion, and an outer surface portion. A first electrically insulated spacer is arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the first end and first end portion. A second electrically insulated spacer is arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the second end and the second end portion.

BACKGROUND

In the resource exploration and recovery industry, it is often times desirable to apply heat to a formation in order to more readily extract formation fluids. In formations that produce heavy oils, heat is applied to stimulate flow. An application of heat may also be used to stimulate extraction of oil from shale. Steam assisted gravity drainage (SAGD) system utilize steam injection in order to stimulate flow. Radio frequency (RF) heating arrangements may also be employed.

An RF heating system is run into a formation on a wireline. Constructing a wireline RF system is time consuming and expensive. Also, the wireline RF heating system includes a heating system that runs continuously from the wellhead to the end of the wireline. Thus, such systems, when operated, may heat, at a constant heating rate, all resource bearing zones in the formation. Accordingly, the industry would welcome an RF heating system that would be easier to construct, less expensive and which could tailor heat input to different zones in the formation.

SUMMARY

Disclosed is a subterranean radio frequency (RF) heating system including a first tubular member having a first end, a second end, an outer surface, and an inner surface. The first tubular member is made from a first electrically conductive material. A second tubular member is arranged radially inwardly of the inner surface of the first tubular member. The second tubular member includes a first end portion, a second end portion, an outer surface portion and an inner surface portion. The first end portion includes a first connector portion and the second end portion includes a second connector portion. The second tubular member is formed from a second electrically conductive material. A first electrically insulated spacer is arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the first end and first end portion. A second electrically insulated spacer is arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the second end and the second end portion.

Also disclosed is a resource exploration and recovery system including a first system having a control system, and a second system including a subterranean radio frequency (RF) heating system. The RF heating system includes a first tubular member having a first end, a second end, an outer surface, and an inner surface. The first tubular member is made from a first electrically conductive material. A second tubular member is arranged radially inwardly of the inner surface of the first tubular member. The second tubular member includes a first end portion, a second end portion, an outer surface portion and an inner surface portion. The first end portion includes a first connector portion and the second end portion includes a second connector portion. The second tubular member is formed from a second electrically conductive material. A first electrically insulated spacer is arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the first end and first end portion. A second electrically insulated spacer is arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the second end and the second end portion.

Still further disclosed is a method of heating a formation includes introducing a radio frequency (RF) heating system including a first tubular member and a second tubular member arranged radially inwardly of and electrically insulated from the first tubular member into a formation, and electrically stimulating the one of the first tubular member and the second tubular member to produce an RF heating zone about the other of the first tubular member and the second tubular member.

DETAILED DESCRIPTION

A resource exploration and recovery system, in accordance with an exemplary embodiment, is indicated generally at10, inFIG. 1. Resource exploration and recovery system10should be understood to include well drilling operations, resource extraction and recovery, CO2sequestration, and the like. Resource exploration and recovery system10may include a first system14which, in some environments, may take the form of a surface system16operatively and fluidically connected to a second system18which, in some environments, may take the form of a subterranean system. First system14may include a control system23that may provide power to, monitor, communicate with, and/or activate one or more downhole operations as will be discussed herein. Surface system16may include additional systems such as pumps, fluid storage systems, cranes and the like (not shown).

Second system18may include a tubular string30, formed from a plurality of interconnected, jointed tubular members, one of which is indicated at32, which extends into a wellbore34formed in a formation36. Wellbore34includes an annular wall38which may be defined by a casing tubular40or by a surface (not separately labeled) of formation36. Plurality of the jointed tubulars32include a subterranean radio frequency (RF) heating system50operatively connected to control system23and which is selectively activated to heat formation36and/or formation fluids in order to promote fluid flow.

In accordance with an exemplary embodiment depicted inFIGS. 2 and 3, RF heating system50includes a first tubular member56and a second tubular member60arranged radially inwardly of first tubular member56. First tubular member56includes a first end64and a second end65. An intermediate portion66defining a continuous outer surface68and a continuous inner surface70extends between first end64and second end65. Continuous inner surface70defines a conduit72that receives second tubular member60. In an embodiment, second end65defines a pin end connector76and first end64defines a box end connector78. First tubular member56is formed from a first electrically conductive material.

Second tubular member60includes a first end portion86and a second end portion87. An intermediate portion88defining a continuous outer surface portion90and a continuous inner surface portion92extends between first end portion86and second end portion87. Continuous inner surface portion92defines a conduit portion94. Conduit portion94and conduit72extend along a central longitudinal axis “L”. Second end portion87includes a first connector portion that defines a pin end connector96and first end portion86includes a second connector portion that defines a box end connector98. Second tubular member60is formed from a second electrically conductive material First and second electrically conductive materials may be similar or, depending upon a desired heat output may be distinct.

Second tubular member60is maintained a fixed distance from continuous inner surface70by a first electrically insulating spacer102and a second electrically insulating spacer104. While shown as including two electrically insulating spacers, the number of electrically insulating spacers may vary. As each spacer102,104is substantially similarly formed, a description will follow with respect to spacer102with an understanding that electrically insulating spacer104includes similar structure. First electrically insulating spacer102includes an outer circumferential edge106that engages continuous inner surface70and a central opening108that receives second tubular member60. In an embodiment, spacers102and104ensure that first and second tubular members56and60only touch at select locations. For example, first and second tubular members56and60only be connected at terminal end portions (not separately labeled) of tubular string30.

In an embodiment, control system23may apply an electrical current to, for example, second tubular member60. The electrical current may induce a radio frequency (RF) response in first tubular member56causing in RF heating system50to generate heat that is passed radially outwardly and into formation36. The heat generated by RF heating system50may be uniform along an entire length of tubular string30. Alternatively, by varying the type of electrically conductive materials used to form first tubular member56and/or second tubular member60, different portions of tubular string30may generate different heat outputs. Further, select portions of tubular string30may not generate heat at all.

Reference will now follow toFIGS. 4 and 5in describing an RF heating system114in accordance with another exemplary embodiment. RF heating system114includes a first tubular member116and a second tubular member120arranged radially inwardly of first tubular member116. First tubular member116defines a first electrical conductor and includes a first end124and a second end125. An intermediate portion126defining a continuous outer surface128and a continuous inner surface130extends between first end124and second end125. Continuous inner surface130defines a conduit132that extends along a central longitudinal axis “L” and which receives second tubular member120. In an embodiment, second end125defines a pin end connector134and first end124defines a box end connector136. First tubular member116is formed from a first electrically conductive material.

Second tubular member120defines a second electrical conductor that extends along longitudinal axis “L” and includes a first end portion142and a second end portion143. An intermediate portion144defining a continuous outer surface portion146extends between first end portion142and second end portion143. First end portion142includes a first connector portion that defines a female electrical connector149and second end portion143includes a second connector portion that defines a male electrical connector151. Second tubular member120may include a substantially solid cross-section and be formed from a second electrically conductive material First and second electrically conductive materials may be similar or, depending upon a desired heat output may be distinct.

Second tubular member120is maintained a fixed distance from continuous inner surface130by a first electrically insulating spacer156, a second electrically insulating spacer157, and a third electrically insulating spacer159. While shown as including three electrically insulating spacers, the number of spacers may vary. As each spacer156,157, and159is substantially similarly formed, a detailed description will follow with respect to spacer156with an understanding that electrically insulating spacers157and159include similar structure.

First electrically insulating spacer156includes an outer circumferential edge162that engages continuous inner surface130of first tubular member116and a central opening164that receives second tubular member120. In an embodiment, spacers156,157, and159ensure that first and second tubular members116and120only touch at select locations. For example, first and second tubular members116and120only connect at terminal end portions (not separately labeled) of tubular string30.

In an embodiment, control system23may apply an electrical current to, for example, second tubular member120. The electrical current may induce a radio frequency (RF) response in first tubular member116causing in RF heating system114to generate heat that is passed radially outwardly and into formation36. The heat generated by RF heating system114may be uniform along an entire length of tubular string30. Alternatively, by varying the type of electrically conductive materials used to form first tubular member116and/or second tubular member120, different zones or portions of tubular string30may generate different heat outputs.

Reference will now follow toFIGS. 6 and 7in describing an RF heating system178in accordance with yet another exemplary aspect. RF heating system178includes a first tubular member180, a second tubular member182, and a third tubular member184. Second and third tubular members182and184are arranged radially inwardly of first tubular member180. First tubular member180includes a first end188and a second end189. An intermediate portion190defining a continuous outer surface192and a continuous inner surface194extends between first end188and second end189. Continuous inner surface194defines a conduit195that extends along a central longitudinal axis “L” and which receives second tubular member182and third tubular member184. In an embodiment, second and third tubular member182and184are equally spaced from central longitudinal axis “L”. Of course, it should be understood that the spacing of second and third tubular members relative to longitudinal axis “L” may vary. In an embodiment, second end189defines a pin end connector198and first end188defines a box end connector200. First tubular member180is formed from a first electrically conductive material.

Second tubular member182includes a first end portion204and a second end portion205. An intermediate portion206defining a continuous outer surface portion208that extends between first end portion204and second end portion205. Second end portion205includes a first connector portion that defines a male electrical connector210and first end portion204includes a second connector portion that defines a female electrical connector212. Second tubular member182may include a substantially solid cross-section and be formed from a second electrically conductive material First and second electrically conductive materials may be similar or, depending upon a desired heat output may be distinct.

Third tubular member184includes a first end section215and a second end section216. An intermediate portion217extends between first end section215and second end section216defining a substantially continuous outer surface portion219. First end section214defines a female electrical connector222and second end section216defines a male electrical connector223. Third tubular member184may include a substantially solid cross-section and be formed from a third electrically conductive material Third electrically conductive material may be similar or identical to first and second electrically conductive materials or, depending upon a desired heat output may be distinct.

Second tubular member and third tubular members182and184are maintained a fixed distance from continuous inner surface194by a first electrically insulating spacer226, a second electrically insulating spacer227, and a third electrically insulating spacer228. While shown as including three electrically insulating spacers, the number of spacers may vary. As each spacer226,227, and228is substantially similarly formed, a detailed description will follow with respect to spacer226with an understanding that electrically insulating spacers227and228include similar structure.

First electrically insulating spacer226includes an outer circumferential edge231that engages continuous inner surface194of first tubular member180, a first opening233and a second opening234. First opening223is receptive of second tubular member182and second opening234is receptive of third tubular member184. In an embodiment, spacers226,227, and228ensure that second and third tubular members184and186only touch first tubular member180at select locations. For example, second and third tubular members184and186only touch first tubular member180at terminal end portions (not separately labeled) of tubular string30.

In an embodiment, control system23may apply an electrical current to, for example, second and third tubular members184and186. The electrical current may induce a radio frequency (RF) response in first tubular member180causing RF heating system178to generate heat that is passed into formation36. The heat generated by RF heating system178may be uniform along an entire length of tubular string30. Alternatively, by varying the type of electrically conductive materials used to form first tubular member180, second tubular member182, and/or third tubular member184, different zones or portions of tubular string30may generate different heat outputs.

Reference will now follow toFIG. 8, wherein like reference numbers represent corresponding parts in the respective views in describing another exemplary aspect of RF heating system178. In an embodiment, conduit portion94may define a flow path250for fluid passing from surface system16. The fluid may be heated by RF heating system50to produce steam which may then be introduced into formation36. Thus, instead of expending energy at surface system16to produce steam, introduce the steam into tubular string30, and flow the steam to a point of injection; the fluid may be heated to a selected temperature by, for example, RF heating system50just prior to injection. In this manner, the exemplary embodiments reduce losses associated with steam flow along tubular string30and reduces an amount of energy needed at surface system16to produce and deliver steam to a point of injection.

In accordance with another exemplary aspect, first electrically insulating spacer102may include one or more passages such as shown at260and second electrically insulating spacer104may include one or more passages such as shown at264. As such, another flow268may be arranged radially outwardly of flow path250, with fluid flowing through passages260and264. Another flow path268may deliver fluid, which may be heated to produce steam, into formation36. In accordance with yet another exemplary aspect, a first fluid may pass along flow path250and a second fluid may pass along another flow path268. The first and second fluids may be heated by RF heating system178and combined to initiate a chemical reaction, such as an exothermic reaction, that produces additional heat. The combined heated fluid may be injected into formation36as part of a treatment operation.

FIG. 9depicts an RF heating system300in accordance with another exemplary aspect. RF heating system300includes a first tubular member304shown in the form of casing tubular40and a second tubular member310which may take the form of a wireline312. Wireline312supports a number of electrically insulating spacers320and322. Spacers320and322are run into wellbore34with wireline312and maintain a desired spacing between first tubular member304and second tubular member310. Each spacer320,322may include corresponding passages, two of which are shown at340and342. Of course, the number and orientation of the passages may vary.

In an embodiment, control system23may apply an electrical current to, for example, second tubular member310. The electrical current may induce a radio frequency (RF) response in first tubular member304resulting in RF heating system300generating heating zone having a selected intensity that acts on formation36. Alternatively, RF heating system300may generate heat that is passed into fluid passing along wellbore34. The heat generated by RF heating system300may be uniform along an entire length of casing tubular40. Alternatively, by varying the type of electrically conductive materials used to form first tubular member304and/or second tubular member310or portions of casing tubular40may generate different RF heating zones having various intensities.

In an embodiment, the RF heating system may extend continuously from surface system16to a toe (not shown) of wellbore34. RF heating system may deliver a uniform heat value or intensity to formation36and/or fluid passing through the first and/or second tubulars. In another exemplary aspect, the RF heating system may be designed to deliver different heat values or intensities depending on depth and/or desired heating characteristics. In yet another exemplary aspect, the RF heating system may be arranged in discrete zones along tubular string30. That is, the RF heating system need not be continuous. That is, the RF heating system may establish a first RF heating zone through a first plurality of tubulars having a first intensity and a second RF heating zone through a second plurality of tubular, spaced from the first RF heating zone, having a second intensity

As an example, the RF heating system may be employed to connect various jewelry components arranged along tubular string30. The RF heating system may establish connections between packers, valves, telescopic joints, screens, drills, mills, or other mechanisms, components or the like that may be run into a wellbore. Still further, it should be understood that the connections between adjoining first tubulars, adjoining second tubulars and, if present, adjoining third tubular may vary and should not be considered to be limited to the connections shown and described herein.

Embodiment 1. A subterranean radio frequency (RF) heating system comprising: a first tubular member having a first end, a second end, an outer surface, and an inner surface, the first tubular member being made from a first electrically conductive material; a second tubular member arranged radially inwardly of the inner surface of the first tubular member, the second tubular member including a first end portion, a second end portion, an outer surface portion and an inner surface portion, the first end portion including a first connector portion and the second end portion including a second connector portion, the second tubular member being formed from a second electrically conductive material; a first electrically insulated spacer arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the first end and first end portion; and a second electrically insulated spacer arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the second end and the second end portion.

Embodiment 2. The subterranean RF heating system according to any prior embodiment, wherein the first end of the first tubular member comprises a box end connector and the second end of the first tubular member comprises a pin end connector, and the first connector portion on the second tubular member comprises a box end connector and the second connector portion of the second tubular member comprises a pin end connector.

Embodiment 3. The subterranean RF heating system according to any prior embodiment, wherein the second tubular member comprises an electrical conductor.

Embodiment 4. The subterranean RF heating system according to any prior embodiment, wherein the first connector portion on the second tubular member is a female electrical connector arranged at the first end and the second connector portion on the second tubular member is a male electrical connector arranged at the second end.

Embodiment 5. The subterranean RF heating system according to any prior embodiment, wherein the subterranean radio frequency (RF) heating system includes a third tubular member, the second tubular member comprises a first electrical conductor and the third tubular member comprises a second electrical conductor, each of the first electrical conductor and the second electrical conductor being radially outwardly spaced from a central longitudinal axis of the first tubular member.

Embodiment 6. The subterranean RF heating system according to any prior embodiment, wherein the first tubular member comprises a casing tubular.

Embodiment 7. A resource exploration and recovery system comprising: a first system including a control system; and a second system including a subterranean radio frequency (RF) heating system comprising: a first tubular member having a first end, a second end, an outer surface, and an inner surface, the first tubular member being made from a first electrically conductive material; a second tubular member arranged radially inwardly of the inner surface of the first tubular member, the second tubular member including a first end portion, a second end portion, an outer surface portion and an inner surface portion, the first end portion including a first connector portion and the second end portion including a second connector portion, the second tubular member being operably connected to the control system and formed from a second electrically conductive material; a first electrically insulated spacer arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the first end and first end portion; and a second electrically insulated spacer arranged between the inner surface of the first tubular member and the outer surface portion of the second tubular member adjacent the second end and the second end portion, wherein the control system selectively activates the first tubular member and the second tubular member to produce RF heating in the formation having a selected heat value.

Embodiment 8. The resource exploration and recovery system according to any prior embodiment, wherein the first end of the first tubular member comprises a box end connector and the second end of the first tubular member comprises a pin end connector and the first connector portion of the second tubular member comprises a box end connector and the second connector portion of the second tubular member comprises a pin end connector.

Embodiment 9. The resource exploration and recovery system according to any prior embodiment, wherein the second tubular member comprises an electrical conductor.

Embodiment 10. The resource exploration and recovery system according to any prior embodiment, wherein the first connector portion on the second tubular member is a female electrical connector arranged at the first end and the second connector portion on the second tubular member is a male electrical connector arranged at the second end.

Embodiment 11. The resource exploration and recovery system according to any prior embodiment, wherein the second tubular member comprises a first electrical conductor and a second electrical conductor, each of the first electrical conductor and the second electrical conductor being radially outwardly spaced from a central axis of the first tubular member.

Embodiment 12. The resource exploration and recovery system according to any prior embodiment, wherein the first tubular member comprises a casing tubular.

Embodiment 13. The resource exploration and recovery system according to any prior embodiment, wherein a first plurality of the plurality of interconnected tubulars includes the subterranean RF heating system having the selected heat value and a second plurality of the plurality of interconnected tubulars includes a subterranean RF heating system including a second heat value.

Embodiment 14. The resource exploration and recovery system according to any prior embodiment, wherein the second tubular member is formed from a first material and the second tubular member is formed from a second material that is distinct from the first material.

Embodiment 15. A method of heating a formation comprising: introducing a radio frequency (RF) heating system including a first tubular member and a second tubular member arranged radially inwardly of and electrically insulated from the first tubular member into a formation; and electrically stimulating the one of the first tubular member and the second tubular member to produce an RF heating zone about the other of the first tubular member and the second tubular member.

Embodiment 16. The method according to any prior embodiment, further comprising: running the RF heating system into the formation as part of a string of interconnected tubulars.

Embodiment 17. The method according to any prior embodiment, further comprising: electrically stimulating the first tubular member and the second tubular member of the RF heating system to produce the RF heating zone having a first intensity and electrically stimulating a first tubular member and a second tubular member of another RF heating system connected to the RF heating system to produce another RF heating zone having a second intensity that is distinct from the first intensity.

Embodiment 18. The method according to any prior embodiment, wherein the RF heating system is operated to create the RF heating zone in a first portion of the formation and the another RF heating system is operated to produce the another RF heating zone in a second portion of the formation that does not adjoin the first portion of the formation.

Embodiment 19. The method according to any prior embodiment, further comprising: introducing a fluid into one of the first tubular member and the second tubular member; heating the fluid with the RF heating system to produce a heated fluid; and injecting the heated fluid into a formation.

Embodiment 20. The method according to any prior embodiment, further comprising: introducing the first fluid into the first tubular member and a second fluid into the second tubular member.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

The terms “about” and “substantially” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and/or “substantially” can include a range of ±8% or 5%, or 2% of a given value.