Embodiments usable within the scope of the present disclosure relate, generally, to threaded couplings and methods, and more specifically to connections and methods usable during drilling-with-casing and/or other oilfield operations.
During drilling-with-casing operations, and/or other operations during which a string of connected tubular segments must be extended and/or retrieved, it is necessary to provide a torque to complementary threaded members sufficient to form a fluid-tight seal therebetween. Conduits that must withstand significant fluid pressures, such as drill pipe and other oilfield tubulars, require a significant torque (up to 50,000 foot-pounds, or more) to form such a seal, while conduits used during drilling-with-casing operations may require an even more robust seal and/or multiple seals. For example, “premium” threaded couplings, such as that disclosed in the United States application for patent having the application Ser. No. 12/925,430, filed Oct. 21, 2010, which is incorporated by reference in its entirety herein, can include multiple seals between connected components. In the industry, premium couplings are often formed using costly materials, such as tubular components having a wall thickness greater than that of standard components.
A need exists for threaded couplings and methods that are usable during drilling-with-casing and other oilfield operations that can be produced using less costly components than those used with existing premium connections, and in various embodiments, using standard (e.g., API) stock materials.
A need also exists for threaded couplings and methods that are usable during drilling-with-casing and other oilfield operations that include features for enabling accurate positioning of components while ensuring integrity of the connection.
Embodiments usable within the scope of the present disclosure meet these needs.
Embodiments usable within the scope of the present disclosure relate to threaded couplings and methods, usable during drilling-with-casing operations and/or other oilfield operations. A first male member (e.g., a pin member) having exterior threads, a first pin nose, and a first exterior shoulder associated with the first pin nose, and a second male member (e.g., a pin member) having exterior threads, a second pin nose, and a second exterior shoulder associated with the second pin nose, can be engaged with a female member (e.g., a box member) having a center, first interior threads engaged with the first exterior threads, and second interior threads engaged with the second exterior threads. A first internal shoulder of the female member can abut the first exterior shoulder of the first male member, and a second internal shoulder of the female member can about the second exterior shoulder of the second male member. Abutment between the internal and external shoulders can thereby position the first pin nose and the second pin nose at the center of the female member. In an embodiment, contact between the first and second pin noses can form a seal therebetween (e.g., when the connection between the male members and the female member is torqued). Such a seal can include a metal-to-metal seal, or in an embodiment, any manner of compressible member (e.g., an o-ring or gasket) could be present at or proximate to the center of the female member and/or one or both pin noses of the male members. In an embodiment, one or more of the internal and/or external shoulders can include a negative angle (e.g., −10 to −20 degrees, and in an embodiment approximately −15 degrees) to facilitate precise positioning of the pin noses and for preventing disengagement between the male and female members (e.g., due to bending moments applied to the coupling).
In a further embodiment, one or a plurality of the threads of the male and/or female members can include a straight thread configuration. Formation of a straight thread configuration on a threaded component typically requires the removal of less material from the component than the formation of other threaded configurations (e.g., tapered threads), such that a threaded coupling that includes a straight thread configuration has a larger maximum width (e.g., thickness) than a similar coupling with an alternate thread configuration. To facilitate the retention of the engagement between complementary threads, the thread form can include negative load flanks and/or a hook thread configuration.
In an embodiment, a bearing journal and/or guide, associated with the exterior threads of either or both male members, can be used to facilitate alignment and engagement between the sets of threads. For example, cylindrical bearing journals can be positioned between the male and female components at the mouth of the coupling e.g., to prevent bending and deflection of the connection when passing through curves, which can prevent “walking” and/or other undesired movement of the engaged threads relative to one another.
In a further embodiment, at least one of the male members can include a tapered external surface (e.g., having a taper angle ranging from 1 degree to 2 degrees, and in an embodiment, approximately 1.75 degrees), which abuts a tapered internal surface of the female member (e.g., having a similar or different taper angle as that of the corresponding male member) to form a metal-to-metal seal between the female member and the one or more male members, thereby enhancing the fluid-tight nature of the coupling in a manner that can be accomplished when the connection is torqued.
In the detailed description of various embodiments of the present invention presented below, reference is made to the accompanying drawings, in which:
Embodiments of the present disclosure are described below with reference to the listed Figures.
Before describing selected embodiments of the present invention in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein. The disclosure and description of the invention is illustrative and explanatory of one or more presently preferred embodiments of the invention and variations thereof, and it will be appreciated by those skilled in the art that various changes in the design, organization, order of operation, means of operation, equipment structures and location, methodology, and use of mechanical equivalents, as well as in the details of the illustrated construction or combinations of features of the various elements, may be made without departing from the spirit of the invention.
As well, the drawings are intended to describe the concepts of the invention so that the presently preferred embodiments of the invention will be plainly disclosed to one of skill in the art, but are not intended to be manufacturing level drawings or renditions of final products and may include simplified conceptual views as desired for easier and quicker understanding or explanation of the invention. As well, the relative size and arrangement of the components may differ from that shown and still operate within the spirit of the invention as described throughout the present application.
Moreover, it will be understood that various directions such as “upper”, “lower”, “bottom”, “top”, “left”, “right”, and so forth are made only with respect to explanation in conjunction with the drawings, and that the components may be oriented differently, for instance, during transportation and manufacturing as well as operation. Because many varying and different embodiments may be made within the scope of the inventive concept(s) herein taught, and because many modifications may be made in the embodiments described herein, it is to be understood that the details herein are to be interpreted as illustrative and non-limiting.
Referring now to
A first pin nose (18), having a face (20), is positioned at a first (e.g., inner) end (24) of the first male component (10). A first external shoulder (22) is shown adjacent to the first pin nose (18) and is usable to position the first pin nose (18) at a desired position within a corresponding (e.g., female) component through abutment between the first external shoulder (22) and a complementary shoulder. While
Proximate to the external shoulder (22), a first tapered external surface (30) (e.g., a sealing surface) is shown, which, upon contact with a corresponding surface (e.g., in a female component) and torquing of the connection, can form a metal-to-metal seal to enhance the integrity of the coupling. While
A bearing journal (28) (e.g., a cylindrical journal and/or similar type of guide) is shown at the second (e.g., outer) end (26) of the first male component (10), such that when the male component (10) is engaged with a corresponding (e.g., female) member, the bearing journal (28) is positioned at the mouth of the coupling and can prevent bending and/or deflection of the connection, such as when passing through curves.
While the dimensions and/or material composition of the first male component (10) can vary depending on the nature of the connection, in an exemplary embodiment, the male component (10) can have an outer diameter of 5.480 inches, a wall thickness of 0.304 inches at its thickest point, and an overall length ranging from 5 to 6 inches. The threads (16) can include a major diameter of 5.460 inches, a minor diameter of 5.368 inches, a thread depth of 0.46 inches, and 6 turns per inch. The taper and/or seal angle of the tapered surface (30) can be 1.7756 degrees, while the shoulder (22) can extend at a negative angle of 15 degrees.
Referring now to
The second male component (32) is shown having a generally cylindrical body (34) with an interior surface (36) opposite exterior threads (38) having a straight thread configuration. A pin nose (40) with a face (42) is shown at a first end (46) of the component (32), adjacent to an associated external shoulder (44) usable to position the pin nose (40) through contact with a complementary shoulder, and in an embodiment, the shoulder (44) can include a negative angle to resist disengagement of the second male component (32) from a complementary (e.g., female) component. A bearing journal or guide (50) is shown at the second end (48) of the component (32), while a tapered external surface (52) is shown adjacent to the shoulder (44), and is usable to form a metal-to-metal seal through contact with a complementary tapered surface.
As described above with reference to
Referring now to
While the dimensions and/or material composition of the female component (54) can vary depending on the nature of the connection, in an exemplary embodiment, the female component (54) can have an overall length of 10.625 inches, and an outer diameter of about 6 inches. The taper and/or seal angle of the tapered surfaces (66, 68) can be 1.7756 degrees, while the shoulders (62, 64) can extend at an angle of about 15 degrees.
Referring now to
Similarly, the second set of exterior threads (38) is shown engaged with the second set of interior threads (60), the engagement and retention of which can be facilitated by the second bearing journal or guide (50). Abutment between the second external shoulder (44) and the second internal shoulder (64) can form a sealed and/or torque engagement, and can facilitate proper positioning of the second pin nose (40). Specifically, the end of the second pin nose (40) is positioned at the center (56) of the coupling, due to contact between the second external and internal shoulders (44, 64). When the connection is torqued, the end of the first pin nose (18) and the end of the second pin nose (40) can be urged into contact with one another, forming a torqued and/or sealed engagement (74), thereby providing the coupling with a generally smooth and/or continuous interior surface that is fluid-tight at the point of connection. Contact between the second tapered external surface and the first tapered internal surface forms a second metal-to-metal seal (78), enhancing the integrity and fluid-tight nature of the connection.
The embodied coupling can thereby incorporate pin nose to pin nose makeup, providing greater torque capacity, while providing the coupling with a generally smooth and/or continuous, fluid-tight interior surface, while using torque shoulders to enable precise positioning of the pin noses, which in an embodiment, can include negative angles to prevent disengagement. Incorporation of metal-to-metal seals between male and female components can further enhance the integrity and fluid-tight nature of the connection, while the use of straight thread forms can minimize the amount of material that must be removed from the tubular stock to form the components, thereby maximizing the thickness and strength of the coupling. Additionally, embodiments can include use of thread forms having negative load flanks, minimizing the possibility of unintentional disengagement of threads. Bearing journals or guides between the male and female components can facilitate engagement of the threads and prevent disengagement through prevention of bending and deflection of the coupling, e.g., through curves. The configurations described above can prevent concentration of high stresses in any point of the coupling, which could otherwise lead to shear failure. Additionally, the ability to engage the male and female components, without over-torquing the coupling, can be gauged both at the face of the coupling, and at the shoulders (e.g., of the male components).
While various embodiments of the present invention have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention might be practiced other than as specifically described herein.
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Number | Date | Country | |
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20150021046 A1 | Jan 2015 | US |