A tubular engagement interface for interfacing the coupling of two movably engaged tubulars is disclosed. The tubular engagement interface includes a body. The body includes a body engagement surface. A polycrystalline diamond element is coupled with the body, and includes a diamond engagement surface. The tubular engagement interface may be coupled with an inner wall of a first tubular, such that the body engagement surface, the diamond engagement surface, or combinations thereof are engaged with an opposing engagement surface of an outer wall of a second tubular. Alternatively, the tubular engagement interface may be coupled with the outer wall of the second tubular, such that the body engagement surface, the diamond engagement surface, or combinations thereof are engaged with an opposing engagement surface of the inner wall of the first tubular.

A coating architecture is disclosed that includes a substrate having a surface finish R.sub.a of 0.3μ or finer, an intermediate layer overlying and in contact with the substrate; and a solid lubricant layer overlying and in contact with the intermediate layer. The test results of applying the coating architecture to a reciprocating hammer drill utilizing the coating is also disclosed.

What is provided is a method and apparatus wherein a swivel can be detachably connected to an annular blowout preventer thereby separating the drilling fluid or mud into upper and lower sections and allowing the fluid to be displaced in two stages, such as while the drill string is being rotated and/or reciprocated. In one embodiment the sleeve or housing can be rotatably and sealably connected to a mandrel. The swivel can be incorporated into a drill or well string and enabling string sections both above and below the sleeve to be rotated in relation to the sleeve. In one embodiment the drill or well string does not move in a longitudinal direction relative to the swivel. In one embodiment, the drill or well string does move longitudinally relative to the sleeve or housing of the swivel.

A method for performing an acid stimulation operation using a downhole tool includes conveying the downhole tool in a borehole that is formed in a subsurface formation. The downhole tool includes a chamber to store stimulation fluid comprising a stimulation acid. The downhole tool includes a fluid injector that is fluidly coupled to an output of the chamber via a flow line of the downhole tool. The method includes coating the flow line with an acid resistant fluid. The method includes injecting, from the fluid injector via the flow line, the stimulation fluid into the subsurface formation that is released through the output of the chamber.

A method and system for servicing a well. Servicing a well often includes running a service string into a production string, which may include a rod string. A service portion is provided in the production string during completion. The service portion is located at or uphole of a large rod string feature. The service portion has a greater inside diameter than production tubing and other standard production string components. The service portion provides sufficient clearance for the service string alongside the large feature. The large feature may be, for example, a PCP stator, a centralizer, or a rod collar. The large feature may be pulled uphole into the service portion prior to running in the service string, allowing servicing downhole of the large feature without pulling the entire rod string. The service portion may also mitigate rod wear in deviated or other portions of the well.

A lineable tubular for use in subterranean exploration and production, such as oil, gas, and geothermal wells. The tubular may be part of a downhole tool string, including drill pipe and related downhole tools that may be found in the bottom hole assembly. The tubular may comprise a modified interior surface along its bore wall. The modified surface may comprise hard particles, rifling, threads, ridges and grooves, sand and ceramic grit, and knurling. The modified surface may aid in securing a liner within the tubular. The tubular may include connectable ends with box and pin end tool joints. The tool joints may be attached to an upset end of the tubular. The modified surface may run the length of the tubular or it may be restricted to the upset ends of the tubular and the respective tool joints. The tubular may comprise a seal gland within the tool joints.

Coating compositions for coating an oilfield operational component, and related methods, may include in some aspects a coating composition having a trifunctional silane, a silanol, and a filler. The coating composition may be applied to a surface of the oilfield operational component that is configured to be exposed to a fluid. The coating composition may be applied to at least partially cover or coat the surface. The coating composition may be configured to chemically bond with a cured primer composition that includes an epoxy.

Coating compositions for coating an oilfield operational component, and related methods, may include in some aspects a coating composition having a trifunctional silane, a silanol, and a filler. The coating composition may be applied to a surface of the oilfield operational component that is configured to be exposed to a fluid. The coating composition may be applied to at least partially cover or coat the surface. The coating composition may be configured to chemically bond with a cured primer composition that includes an epoxy.

Coating compositions for coating an oilfield operational component, and related methods, may include in some aspects a coating composition having a trifunctional silane, a silanol, and a filler. The coating composition may be applied to a surface of the oilfield operational component that is configured to be exposed to a fluid. The coating composition may be applied to at least partially cover or coat the surface. The coating composition may be configured to chemically bond with a cured primer composition that includes an epoxy.

Coating compositions for coating an oilfield operational component, and related methods, may include in some aspects a coating composition having a trifunctional silane, a silanol, and a filler. The coating composition may be applied to a surface of the oilfield operational component that is configured to be exposed to a fluid. The coating composition may be applied to at least partially cover or coat the surface. The coating composition may be configured to chemically bond with a cured primer composition that includes an epoxy.