SOLID STATE PIPE DOPE

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority of U.S. Provisional Patent Application No. 62/570419 entitled "SOLID STATE PIPE DOPE," filed October 10, 2017, the contents of which are hereby incorporated by reference. FIELD OF THE INVENTION

The present disclosure relates to a method and composition for lubricating pipe joints. More particularly, the invention relates to a dry pipe dope formed into a cone or other receptacle shape for locating on a pipe end.

BACKGROUND OF THE INVENTION

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described 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 disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

Pipe dope is a term used to refer to thread lubricant, thread sealing compound, and sealants for application to a pipe thread joint. Treating pipe threads with pipe dope is for making a pipe thread joint leak proof and pressure tight. Untreated threaded joints that are mechanically tightened tend to seize over a period of time. Additionally, untreated or uncoated threaded joints have poor sealing properties in vacuum applications or in high pressure applications. Although common pipe threads are tapered to achieve an interference fit during proper assembly, machining and finishing variances may cause a fit that does not achieve complete contact between the mating components. The application of pipe dope prior to assembly fills voids between the threads, thus making the joint pressure tight. Pipe dope also acts as a lubricant and helps prevent seizing of the mating parts, which can later cause difficulty during disassembly. Typical pipe doping techniques include applying pipe dope manually with a brush, or using an automated pipe bucket to spray pipe dope on a pipe using high pressure air.

Pipe dope may be applied to drill pipe j oints. The enlarged and threaded ends of j oints of drill pipe are typically fabricated separately from the pipe body and welded onto the pipe at a manufacturing facility. The tool joints provide high-strength, high -pressure threaded connections that are sufficiently robust to survive the rigors of drilling and numerous cycles of tightening and loosening at threads. Tool joints are usually made of steel that has been heat treated to a higher strength than the steel of the tube body. The large-diameter section of the tool j oints provides a low stress area where pipe tongs are used to grip the pipe.

Spraying or brushing finely powdered graphite or other solid lubricants upon joints prior to threading them together has been generally successful in preventing seizing. Attempts have been made to obtain advantages of both finely powdered solid lubricants and liquid or semisolid oils or nondrying polymers by combining the finely powdered solid lubricants and oils, greases, or nondrying polymers. A disadvantage of typical prior art pipe lubricants is that they are messy to use and readily soil hands, clothing and the like. Additionally, the application of pipe lubricants may be time consuming, requiring the oils and greases to be applied on the threads, with the possibility of incomplete coverage of the threads. Example patents related to drill pipe lubricant includes the following: USPN 3,007,866 for, "Drill pipe lubricant containing graphite" by Francis E Chamberlin, filed date June 23, 1959; USPN 3,751,363 for "Pipe thread lubricant stabilized with organic sulfides" by M. Johnson, R. Rohde, filed date February 9, 1971 ; USPN 3,114,709 for, "Pipe thread lubricant" by Francis E Chamberlin, filed February 1, 1961; USPN 3,423,315 for, "Pipe thread lubricant" by Paul R. McCarthy and Thomas R. Orem, filed May 4, 1967; USPN 5,885,941 for, "Thread compound developed from solid grease base and the relevant preparation procedure" by Milka Sateva, Marija Koren-Markovic, Ljerka Kondres, Sajma Zajcic, and Nikola Janusic, filed November 4, 1997; USPN 3,869,393 for, "Solid lubricant adhesive film" by Aylwin Reed Booker, filed April 7, 1972. An example device for cleaning and lubricating the external/internal threads of pipe end couplings is WO 1999/060245 for, "Cleaning and lubricating device for threads, especially for drill pipes" by Jon Ame Gjeseth, filed April 27, 1999.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining or limiting the scope of the claimed subject matter as set forth in the claims.

A solid lubricant is provided for lubricating a threaded connection such as a drill pipe connection. A dry lubricant or solid lubricant is formed into a shaped structure adapted for being received at a connecting end of a tubular, such as a drill pipe. In one embodiment, the shaped structure is adapted to be located within a box end of a drilling tubular and/or on a pin end of a drilling tubular. The shaped structure may be frustum shaped, cone shaped, or bucket shaped.

In use, a threaded connection, such as a drill pipe connection, may be lubricated by forming a dry lubricant or solid lubricant into a shaped structure adapted for being received on an end of a tubular, such as a drilling tubular. The shaped structure may be located in a box end or on a pin end of the drilling tubular by a manual placement of the shaped structure or may be positioned by a locating device fitted with a dispenser, such as an iron roughneck or pipe handling system.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject disclosure is further described in the following detailed description, and the accompanying drawing and schematic of non-limiting embodiment of the subject disclosure. The features depicted in the figure are not necessarily shown to scale. Certain features of the embodiments may be shown exaggerated in scale or in somewhat schematic form, and some details of elements may not be shown in the interest of clarity and conciseness.

FIG. 1A is a perspective exploded view of a shaped structure in the form of a dope cone being located between a pin end and a box end of a drill pipe tool joint;

FIG. IB is a perspective view of the shaped structure in the form of a dope cone placed on the pin end of a drill pipe tool joint and inserted into the box end of the drill pipe tool joint;

FIG. 1C is a perspective view of the drill pipe tool joint of FIGS. 1A and IB after a connection has been completed, thereby encasing the shaped structure;

FIG. 2A is a perspective view of a first embodiment of the shaped structure of FIGS.

1A-1C;

FIG. 2B is a perspective view of a second embodiment of the shaped structure of FIGS. 1A-1C;

FIG. 2C is a perspective view of a third embodiment of the shaped structure of FIGS.

1A-1C;

FIG. 3 is a perspective view of a locating device for locating the shaped structure. Elements and Numbering Used in the Drawings

10 solid lubricant

12 connection shaped structure first tubular pin end

external threads lower mating surface second tubular box end

internal threads upper mating surface cone shape upper end lower end bucket shape upper end lower end small cone shape upper end lower end locating device DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

One or more specific embodiments of the present disclosure will be described below. These described embodiments are only exemplary of the present disclosure. 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.

Solid lubricant 10 is provided for lubricating connection 12, such as a drill pipe connection. Dry lubricants or solid lubricants are solid phase materials that are able to reduce friction between two surface sliding against each other without the need for a liquid oil medium. Referring to Figures 1A through 1C, shown is solid lubricant 10 formed into solid structure 14. Example solid lubricants include graphite, molybdenum disulfide (M0S2), hexagonal boron nitride, and tungsten disulfide. Shaped structure 14 is adapted for being received within connection 12.

Connection 12 is formed by first tubular 20, such as a drilling tubular, and a second tubular, such as second drilling tubular 30. First tubular 20 defines pin end 22. Pin end 22 defines external threads 24 and lower mating surface 26.

Second tubular 30 defines box end 32 that defines internal threads 34. Second tubular 32 defines upper mating surface 36 for engagement with lower mating surface 26. In one embodiment, shaped structure 14 is a frustrum shape 40 (FIGS. 1A, IB, 2 A). Frustum shape 40 includes upper end 42 and lower end 44. Upper end 42 is sized to receive external threads 24 of first tubular 20. Lower end 44 is sized to be received within internal threads 34 of box end 32 of second tubular 30. In one embodiment, cone shape 40 may be between one and thirty inches deep and have a lower end of between one and forty inches in diameter and an upper end of between one and forty inches in diameter. Walls of frustum shape 40 may have a thickness of between .0004 and 1.0 inches.

Referring now to Figure 2B, a second embodiment of solid structure is a more cylindrical frustum shape 50. Frustum shape 50 defines upper end 52 and lower end 54. In one embodiment, frustum shape 50 may be between one and thirty inches deep and have a lower end of between one and forty inches in diameter and an upper end of between one and forty inches in diameter. Walls of frustum shape 50 may have a thickness of between .0004 and 1.0 inches.

In one embodiment, shaped structure 14 is a small frustum shape 60 (FIG. 2C). Small frustum shape 60 has upper end 62 and lower end 64. In one embodiment, small cone shape 60 may be between one and thirty inches deep and have a lower end of between one and forty inches in diameter and an upper end of between one and forty inches in diameter. Walls of small frustum shape 60 may have a thickness of between .0004 and 1.0 inches.

In use, a solid lubricant 10 is formed into shaped structure 14 adapted for being received on pin end 22 of first tubular 20 and for locating in box end 32 of second tubular 30 so that solid lubricant 10 is trapped between pin end 22 and box end 32 for lubricating the threaded connection therebetween. Placement of shaped structure 14 may be a manual operation consisting of locating shaped structure 14 into box end 32 of second tubular 30 or placing shaped structure 14 on pin end 22 of first tubular 20. In one embodiment, placement of shaped structure 14 is an automated operation wherein shaped structure 14 is located proximate to pin end 22 of first tubular 20 and/or proximate to box end 32 of second tubular 30. In one example, automated operation is facilitated by locating device 70, such as a specially adapted iron roughneck as shown in Figure 3 or by other pipe handling system, such as large capacity self-locking wrenches, that are typically used to grip drill string components and to apply torque.

While the disclosure 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 disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the following appended claims.

The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as "means for" or "step for" performing a function, it is intended that such elements are to be interpreted under 35 U.S.C. 1 12(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 1 12(f).