Patent Application
20240287876
This disclosure relates to wellbore equipment, and more particularly to equipment for wellbore drilling and completion.
Wells can be used for hydrocarbon production or other purposes such as for well stimulation or fluid injection. In the case of production wells, a wellbore can be drilled into a hydrocarbon-rich geological formation to extract hydrocarbons from the formation. Before beginning production, a completion system is installed to prepare the wellbore for production or injection. The completion system can include one or more casings or liners cemented in the wellbore to help control the well and maintain well integrity. Methods and equipment for operating and maintaining cased wellbores are sought.
Implementations of the present disclosure include a wellbore completion system having a tieback string and a seal system. The tieback string includes a receptacle end defining an inner diameter larger than an outer diameter of a liner. The liner is configured to be disposed within a wellbore. The liner is configured to define an annulus between an external surface of the liner and a wall of the wellbore. The receptacle end is configured to be disposed within the annulus to receive a portion of the liner. The seal system is coupled to an internal surface of the receptacle end. The seal system includes an annular seal configured to swell inwardly upon contact to a wellbore fluid having an oil-based fluid to form, with the portion of the liner inserted within the receptacle end, a seal with the external surface of the liner. The tieback string is fluidly coupled, with the seal formed, to the liner to receive production fluid from the liner.
In some implementations, the wellbore extends from a terranean surface to a geological formation having a hydrocarbon reservoir. The tieback string includes a tubular body extending from the terranean surface through the wellbore to the receptacle end. The tubular body defines an inner diameter substantially equal to or greater than an inner diameter of the liner.
In some implementations, the annular seal includes at least one swellable seal which swells upon contact to the wellbore fluid having the oil-based fluid to form the seal. In some cases, the one swellable seal swells responsive to the wellbore fluid at a temperature of between 150 and 350 degrees Fahrenheit touching the at least one swellable seal. In some cases, an elastomer of the at least one swellable seal swells over a time period of 3 to 5 days to form the seal responsive to absorbing the wellbore fluid. In some cases, the at least one swellable seal swells absent mechanical movements of the tieback string and absent fluid pumped downhole through the tieback string.
In some implementations, the liner is partially cemented in the wellbore, the annulus extending from an uphole inlet of the liner to a liner hanger or cement disposed between the liner and a wall of the wellbore.
In some implementations, the liner includes a monobore completion liner, and the portion of the liner has an uphole fluid inlet formed upon cutting the liner and retrieving a second portion of the liner uphole of the portion of the liner.
In some implementations, the wellbore fluid includes the oil-based fluid having at least one of a diesel fluid, an oil-based drilling mud, a diesel-based drilling mud, a production fluid extracted from a hydrocarbon reservoir into the wellbore, an oil-based emulsion mixture, or an oil-based completion fluid.
In another aspect, a wellbore assembly includes a casing pipe and a wellbore string. The casing pipe has an external surface. The casing pipe is configured to be disposed within a wellbore having a wall. The external surface of the casing pipe and the wall of the wellbore define an annulus. The wellbore string has a downhole end defining an inner diameter larger than an outer diameter of an uphole end of the casing pipe. The downhole end includes an internal annular seal which expands upon contact to a wellbore fluid having an oil-based fluid to form, with the uphole end of the casing pipe inserted within the downhole end of the wellbore string, a seal with the external surface of the casing pipe. The wellbore string is fluidly coupled, with the seal formed, to the casing pipe to flow fluid between the wellbore string and the casing pipe.
In some implementations, the wellbore string includes a tubular body extending from a terranean surface of the wellbore to the downhole end. The tubular body defines an inner diameter equal to or greater than an inner diameter of the casing pipe.
In some implementations, the internal annular seal includes at least one swellable seal which swells upon contact to the wellbore fluid having an oil-based fluid to form the seal. In some cases, the at least one swellable seal swells responsive to the wellbore fluid at a temperature of between 150 and 350 degrees Fahrenheit when the wellbore fluid touching the at least one swellable seal. In some cases, an elastomer of the at least one swellable seal swells responsive to absorbing the wellbore fluid over a period of time to form a seal with an unpolished or uneven surface of the casing pipe. In some cases, the wellbore string further includes internal grooves positioned at the downhole end of the wellbore string. Each swellable seal is disposed within a respective internal groove. Each swellable seal includes a compliant external surface which swells from the respective internal groove toward the external surface of the casing pipe.
In some implementations, the casing pipe is partially cemented in the wellbore. The annulus extends from an uphole inlet of the casing pipe to a casing pipe hanger, packer, or cement disposed between the casing pipe and a wall of the wellbore.
In some implementations, the seal fluidly isolates the annulus from a bore of the wellbore string and a bore of the casing pipe.
In some implementations, the casing pipe includes a monobore completion casing pipe, and a portion of the casing pipe has an uphole fluid inlet formed upon cutting the casing pipe and retrieving a second portion of the casing pipe uphole of the portion of the casing pipe.
In some implementations, the wellbore fluid having the oil-based fluid includes at least one of a diesel fluid, an oil-based drilling mud, a diesel-based drilling mud, a production fluid extracted from a hydrocarbon reservoir into the wellbore, an oil-based emulsion mixture, or an oil-based completion fluid.
In yet another implementation, a method includes running a tieback string within a wellbore to a liner positioned in the wellbore. The tieback string includes a receptacle end having an inner diameter larger than an outer diameter of the liner. The receptacle end includes an annular seal which swells inwardly upon contact to a wellbore fluid having an oil-based fluid to form, with a portion of the liner inserted within the receptacle end, a seal with an external surface of the liner. The method includes positioning the receptacle end around a portion of the liner about the external surface of the liner. The method includes, upon contact to the wellbore fluid having the oil-based fluid, activating the annular seal to form, with the external surface of the liner, a seal. The tieback string is fluidly coupled, with the seal formed, to the liner to receive production fluid from the liner.
In some implementations, before running the tieback string within the wellbore, the method includes cutting the liner and retrieving an upper portion of the liner to form the portion of the liner.
In some implementations, activating the annular seal includes flowing, from a terranean surface of the wellbore and through the tieback string, the wellbore fluid having an oil-based fluid. The annular seal swells responsive to contact with the wellbore fluid having the oil-based fluid at a temperature of between 150 and 350 degrees Fahrenheit.
In some implementations, the wellbore fluid includes the oil-based fluid having at least one of a diesel fluid, an oil-based drilling mud, a diesel-based drilling mud, a production fluid extracted from a hydrocarbon reservoir into the wellbore, an oil-based emulsion mixture, or an oil-based completion fluid.
The present disclosure relates to methods and equipment for providing a tieback string in a wellbore without reducing the internal diameter of the completion system and while reducing the complexity of installing a tieback string. A tieback string (e.g., a tie-back liner or a drilling tie-back) is a piping string that extends from a terranean surface of the wellbore to a liner to fluidly connect the liner to the surface. A tieback string can be used to provide the necessary pressure capacity during a flow-test period or for special treatments, and is typically not cemented in place. In some cases, a tieback string can be installed as a remedial solution when the integrity of the intermediate casing string is in doubt. For example, the wellbore casing (or other tubulars) can be exposed to extreme corrosive and abrasive conditions that adversely affect the casing and well integrity by reducing the wall thickness or otherwise damaging the casing. The tieback string can be installed to flow the wellbore fluids without exposing the damaged casing to the wellbore fluids.
The tieback string of the present disclosure includes a piping string and a receptacle end with internal seals. The internal seals expand or swell to form a seal with an external surface of the liner. The internal seals can be swellable seals that are expand upon coming into contact with a hot fluid flow from the surface or from the formation to the surface.
Particular implementations of the subject matter described in this specification can be implemented so as to realize one or more of the following advantages. For example, the tieback system of the present disclosure can provide a tieback string without reducing the internal diameter of the production (or injection) tubing, and thus maintaining or increasing the flow rate of the wellbore and providing full wellbore accessibility. The tieback system of the present disclosure can also reduce operational complexity by providing a seal with rough or uneven surfaces, and eliminate the need of additional scraper runs to clean casing surfaces especially during re-completion operations. Additionally, the tieback system of the present disclosure may not require any axial or rotational movement or force to set and expand the sealing elements. Additionally, the tieback system of the present disclosure may not require hydraulic pressure or pumping any fluids to activate the sealing elements. Such features can help minimize the number of trips needed for re-completion or otherwise attaching a tieback string to a liner.
The wellbore 102 is shown as a vertical wellbore, however, the concepts of the present disclosure are applicable to other different configurations of wells, including horizontal wellbores, slanted wellbores (or otherwise deviated wellbores), wellbores with partially cemented monobore tubing, wellbores with long-string casing, or wellbores with partially cemented monobore casing. The wellbore 102 extends from surface equipment 112 such as a wellhead or a rig.
The liner 110 can be installed within the wellbore 102 during completion of the wellbore 102. The liner 110 is partially cemented with a cement layer “C.” For example, the liner 110 has an upper or uphole portion 115 exposed to form, with the wall 113 (e.g., the casing wall) of the wellbore 102, an empty annulus “A.” The liner 110 can be attached to the casing 107 and cemented below the casing, or (as shown in
The liner 110 can extend from the surface 111 to the production area to form a monobore completion (e.g., with the liner 110 arranged as a monobore completion with cemented liner). For example, the liner 110 extends from the surface 111 of the wellbore 102 to the target zone or reservoir 105 to flow the production fluid “F” to the surface. The liner 110 can have one or more defects 117 (e.g., corrosion, erosion, pinhole, micro-cracks, fractured pipe, tubular wall thickness reduction, over-torque joint, collapsed pipe, burst pipe, or any obstruction or internal diameter reduction) at the uphole portion. The defect can serve as a point of reference for the location of the cut (the cut being below the lowest defect) to remove the defective liner section that extends from the cut to the surface 111 of the wellbore.
Referring now to
The receptacle end 108 has a seal system 124 that is coupled to an internal surface of the receptacle end 108. As shown in
As shown in
Swellable sealing systems can be robust sealing systems that swell and establish proper sealing with rough surfaces. In some cases, swellable seals can seal open hole rough surfaces. The seals swell to adapt to the uneven or deformed cross-section of the liner and form a fluid-tight seal even when the liner is deformed. Additionally, the swellable seals do not require any slack off, compression, tension, slip mechanism, or thread systems to activate or form the seal. Additionally, the tieback system does not require hydraulic pressure or pumping any fluids to activate the sealing elements. Moreover, the swellable seals are robust and can establish proper sealing with rough surfaces of the pipe. In other words, the swellable seal system does not required polished surfaces for proper sealing. Such features can help minimize the number of trips needed for re-completion or for attaching a tieback string to a liner.
The seal system 124 can provide an immediate seal or a seal that is formed over time as the seals 206 swell slowly. The swellable seals 206 can be activated or reactivated after a shrinking or other deterioration of the swellable seal. The swellable seals 206 can swell in response to an activation fluid (wellbore fluids) containing one or more oil-based fluids by contacting the swellable seal or seals, for example, at any point during the life of a well. For example, the oil-based fluid can be one or more of a diesel fluid, an oil-based drilling mud, a diesel-based drilling mud, a production fluid extracted from a hydrocarbon reservoir into the wellbore, an oil-based emulsion mixture, or an oil-based completion fluid.
In some implementations, each swellable seal 206 is disposed within a respective internal groove “g” of the receptacle end 108. For example, the internal surface or bore of the receptacle end 108 has annular grooves “g” that house each annular seal 206. Each swellable seal 206 has a compliant external surface that swells or expands from the groove “g” toward the external surface of the liner 110 to form the seal.
The tubular body 132 of the tieback string 130 can extend from or near the surface of the wellbore 102 to the receptacle end 108. The tubular body 132 has an inner diameter “d1” substantially equal to or greater than an inner diameter “d2” of the liner 110. Thus, the tubular body 132 does not reduce the flow rate capacity of wellbore or of the liner 110.
Although the present implementations have been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereupon without departing from the principle and scope of the disclosure. Accordingly, the scope of the present disclosure should be determined by the following claims and their appropriate legal equivalents.
The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.
As used in the present disclosure and in the appended claims, the words “comprise,” “has,” and “include” and all grammatical variations thereof are each intended to have an open, non-limiting meaning that does not exclude additional elements or steps.
As used in the present disclosure, terms such as “first” and “second” are arbitrarily assigned and are merely intended to differentiate between two or more components of an apparatus. It is to be understood that the words “first” and “second” serve no other purpose and are not part of the name or description of the component, nor do they necessarily define a relative location or position of the component. Furthermore, it is to be understood that the mere use of the term “first” and “second” does not require that there be any “third” component, although that possibility is contemplated under the scope of the present disclosure.
