Patent Application
20130032348
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
As will be appreciated, oil and natural gas have a profound effect on modern economies and societies. Indeed, devices and systems that depend on oil and natural gas are ubiquitous. For instance, oil and natural gas are used for fuel in a wide variety of vehicles, such as cars, airplanes, boats, and the like. Further, oil and natural gas are frequently used to heat homes during winter, to generate electricity, and to manufacture an astonishing array of everyday products.
In order to meet the demand for such natural resources, companies often invest significant amounts of time and money in searching for and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired resource is discovered below the surface of the earth, drilling and production systems are often employed to access and extract the resource. These systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a wellhead assembly through which the resource is extracted. These wellhead assemblies may include a wide variety of components, such as various casings, valves, fluid conduits, and the like, that control drilling and/or extraction operations.
To extract the resources from a well, a drilling riser may extend from the well to a rig. For example, in a subsea well, the drilling riser may extend from the seafloor up to a rig on the surface of the sea. A typical drilling riser may include a flanged assembly formed from steel, and the drilling riser may perform multiple functions. In addition to transporting drilling fluid into the well, the riser may provide pipes to allow drilling fluids, mud, and cuttings to flow up from the well. A drill pipe may be disposed inside the riser and connected to a drillbit or other tool at the end of the well. The riser may be coupled to a blowout preventer (BOP) that can seal off the well in certain situations.
During the drilling operation, operators may lose control of the well if unexpected or excess pressure occurs. Additionally, other events, such as weather, may cause operators to seal off the well in an emergency. During such events, the BOP may seal off the well, such as through the activation of rams in the BOP. These rams may bend, cut, shear, or otherwise deform the drill pipe or other components in the wellhead. The drill pipe, tools, or other equipment left in the well are referred to as “fish.” Retrieval of the fish may be challenging, time-consuming, and expensive.
Various features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying figures in which like characters represent like parts throughout the figures, wherein:
One or more specific embodiments of the present invention will be described below. These described embodiments are only exemplary of the present invention. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
Embodiments of the present invention include a fishing tool to enable retrieval of fish from components of a mineral extraction system. The retrieval tool may include an upper frustoconical member, an outer tubular member, and an inner tubular member concentrically disposed around an axis. The fishing tool may be moved between an “unlocked position” and a “locked position,” such that in the “locked position” the fishing tool is engaged with the fish to enable removal of the tool and the fish. The inner tubular member may include receptacles configured to receive a plurality of jaws having teeth on an inward facing surface. The outer tubular member may also include recesses to retain the jaws. The outer tubular member may be hydraulically actuated to translate, relative to the frustoconical member and inner tubular member, in an axial direction. The movement of the outer tubular member causes an angled surface of the recesses to exert an inward radial force on the jaws, causing the jaws to move radially inward and engage, e.g., “bite,” into the fish. After engagement with the fish, the fishing tool and the fist may be removed.
The wellhead assembly 12 typically includes multiple components that control and regulate activities and conditions associated with the well 16. For example, the wellhead assembly 12 generally includes pipes, bodies, valves and seals that enable drilling of the well 16, route produced minerals from the mineral deposit 14, provide for regulating pressure in the well 16, and provide for the injection of chemicals into the well-bore 18 (down-hole). For example,
The BOP 26 may consist of a variety of valves, fittings and controls to prevent oil, gas, or other fluid from exiting the well in the event of an unintentional release of pressure or an unanticipated overpressure condition. As used herein the term “BOP” may also refer to a “BOP stack” having multiple preventers. The BOP 26 may be hydraulically operated and may close the wellhead assembly 12 or seal off various components of the wellhead assembly 12. During operation of the system 10, a BOP 26 may be installed during removal or installation of additional components, changes in operation of the system 10, or for other safety reasons. The BOP 26 may be any suitable BOP, such as a ram BOP, an annular BOP, or any combination thereof. The BOP 26 shown in
A drilling riser 28 may extend from the BOP 26 to a rig 30, such as a platform or floating vessel. The rig 30 may be positioned above the well 16. The rig 30 may include the components suitable for operation of the mineral extraction system 10, such as pumps, tanks, power equipment, and any other components. The rig 30 may include a derrick 32 to support the drilling riser 28 during running and retrieval, a tension control mechanism, and any other components.
The drilling riser 28 may carry drilling fluid (e.g., “mud) from the rig 30 to the well 16, and may carry the drilling fluid (“returns”), cuttings, or any other substance, from the well 16 to the rig 30. The drilling riser 28 may include a drill pipe 34. The drill pipe 34 may be connected centrally over the bore (such as coaxially) of the well 16, and may provide a passage from the rig 30 to the well 16.
During operation of the mineral extraction system 10, different events may result in closing and sealing of the well 16. For example, a loss of control of the well 16 and/or a sudden increase in pressure may result in activation of the BOP 26 to seal off the well. Additionally, in some events, such as bad weather, the rig 30 may stop any operation in the well 16 and relocate to avoid or minimize exposure to the weather. Such events may include or be described as an Emergency Disconnect Sequence (“EDS”).
As described above, the BOP 26 may seal off the well 16 through operation of the rams 27, such as by the rams closing and sealing the well-bore 18. In some embodiments, the rams 27 may shear, cut, bend, or otherwise deform the drill pipe 34 to allow extraction of the upper portion 35 of the drill pipe 34 from the well. However, the lower portion 36 of the drill pipe 34 may remain in the well 16. The drill pipe 34 or other material left in the well 16 may be referred to as “fish”. Before restarting an operation on the well 16, the fish may be removed from the well 16. However, the deformed portion of the drill pipe 34 presents an unusual shape to retrieve, as well as preventing or increasing the difficulty of attaching retrieval tool to the drill pipe 34.
The upper frustoconical member 42 of the fishing tool 40 may be secured to the outer tubular member 44 by one or more fasteners 52, such as screws, bolts, welds, rivets, etc. The upper frustoconical member 42 includes one or more holes 54 to enable release of any fluid in the well as the tool is inserted (“run”) into the well. The upper frustoconical member 42 also includes a tubular protrusion 56 having a reduced diameter. The tubular protrusion 56 provides a secure attachment point for any tool or pipe used to insert the fishing tool 40 into components of the mineral extraction system 10. For example, in one embodiment, the fishing tool 40 may be secured to the bottom portion of another drill pipe inserted into the BOP 26. The outer tubular member 44 may be coupled to the inner tubular member 46 through engagement of a plurality of tabs 45 of the inner tubular member 46 and corresponding holes 47 configured to receive the tabs.
The inner tubular member 46 includes receptacles 60 configured to receive the jaws 50. The receptacles 60 may include upper angled surfaces 62 and lower angled surfaces 64 that secure the jaws. As explained further below, the jaws 50 may move radially towards the central axis 48 when the tool 40 is actuated. The inner tubular member 46 also includes holes 63 to enable release of any fluid in the well as the tool is inserted (“run”) into the well. The outer tubular member 44 may include angled interior surfaces that engage and move the jaws 50 when the outer tubular member 44 is translated. The jaws 50 may be secured in the receptacle 60 and disposal of the outer tubular member 44 over the inner tubular member 46 may further secure the jaws 50 in the receptacles 60. The outer tubular member 44 may also include holes 65 to enable release of any fluid in the well as the tool is inserted (“run”) into the well 16.
As further shown in
As described above, the inner tubular member 46 may include holes 63 disposed around the circumference of the inner tubular member 46. When inserting the fishing tool 40 into the components of the mineral extraction system 10, the holes 63 may allow the fishing tool 40 to displace mud or other fluid so that the fishing tool 40 can be inserted to the desired position. Further, the holes 65 of the outer tubular member 44 may also allow mud or other fluid to be displaced as the fishing tool 40 is inserted.
As noted above, the upper member 42 of the fishing tool 40 may include one or more hydraulic lines 70 that are in hydraulic communication with chamber 68. The chamber 68 may be an annular space defined by the interface of the upper member 42 and the outer tubular member 44 and seals 67 and 69. As mentioned above, the jaws 50 may be captured by receptacles 60 of the inner tubular member 46 and the recesses 71 of the outer tubular member 44. The recesses 71 may include upper angled surfaces 72 and lower angled surfaces 74. As explained below, when the fishing tool 40 is moved from an unlocked position to a locked position, the translation of the outer tubular member 44 in the axial direction indicated by arrow 90 may cause the lower angled surface 74 of the recess to move the jaw 50 into engagement with the fish, e.g., to e.g., “bite” the wall of the drill pipe 34.
As mentioned above, in the position shown in
After the fishing tool 40 is lowered into a desired position, the fishing tool 40 may be set in a “locked position.” To set the fishing tool to the “locked position,” hydraulic fluid may be applied to the chamber 68 through hydraulic lines 70. The hydraulic fluid causes the chamber 68 to expand, translating the outer tubular member 44 relative to the upper member 42 in the axial direction indicated by arrow 90. The movement of the outer tubular member 44 causes the lower angled surfaces 74 of the recesses 71 to exert an inward radial force on the jaws 50, as illustrated by arrow 92. The jaws 50 may move inward in the radial direction indicated by arrow 92, engaging the teeth 64 of the jaws 50 with the drill pipe 34. In some embodiments, the hydraulic fluid may be contained in the pipe used to suspend and manipulate the tool 40, e.g., the pipe coupled to the protrusion 56.
After the tool 40 is positioned, hydraulic pressure may be applied to the hydraulic chamber 68 to move the fishing tool 40 to the locked position (block 110). As described above, application of hydraulic pressure to the chamber 68, causes the outer tubular member 44 to translate in the axial direction to an upper position toward the upper member 40 (block 112). The movement of the outer tubular member 44 causes the lower angled surfaces 74 to apply a radially inward force to the jaws 50, moving the jaws 50 in a radially inward direction to engage (e.g., “bite”) the fish (block 114). After locking the tool 40 and engaging the jaws 50 with the fish, the fishing tool 40 and the fish may be removed from the BOP 26 and out of the well 16 (block 116).
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
