Abstract: A reciprocating drive apparatus (10) comprises a housing (12) and a mandrel (14), wherein the mandrel (14) and the housing (12) are configurable to be rotated relative to each other. The apparatus (10) further comprises a reciprocating piston (16) mounted within a piston housing (18) to define a piston chamber (20a), wherein the piston (16) is moveable in reverse first and second axial directions (A,B), and a rotary valve assembly (24) comprising a valve inlet (28) for communicating with a pressure region (P) and a valve exhaust (30) for communicating with an exhaust region (E). The rotary valve assembly (24) is operated by relative rotation between the mandrel (14) and the housing (12) to be cyclically reconfigured between a pressure configuration and an exhaust configuration.

Abstract: A downhole drag reducing apparatus 18 comprises a mandrel 20 and a bearing sleeve 24 mounted on the mandrel 20, such that the mandrel 20 and bearing sleeve 24 are rotatable relative to each other. The bearing sleeve 24 defines a bore wall engaging surface. The apparatus 18 comprises a reciprocating piston 23 mounted within a piston housing 25 to define a piston chamber 27. The apparatus 18 further comprises a rotary valve assembly 29 operated by relative rotation between the mandrel 20 and the bearing sleeve 24 to cyclically pressurise and depressurise the piston chamber 27 to provide reciprocating movement of the reciprocating piston 23 and the generation of vibration within the apparatus 18.

Abstract: A swivel (100) is described comprising a first swivel member (112) comprising a first load shoulder (116) and a second swivel member (115) comprising a second load shoulder (118). The first and second swivel members are rotatable relative to each other. A deformable bearing component (142) is provided within a cavity (140) defined between the first and second load shoulder (116, 118). The deformable bearing component (142) facilitates load transmission between the first and second load shoulders (116, 118) and is deformable to accommodate variations in alignment between the first and second load shoulders (116, 118).

Abstract: A thrust bearing is described comprising first and second bearing assemblies (15, 17) rotatable relative to each and a plurality of axially arranged bearing stages (14a, 14b) formed between the first and second bearing assemblies (15, 17). Each bearing stage comprises a first load shoulder (16) provided on the first bearing assembly (15), a second load shoulder (18) provided on the second bearing assembly (17), a bearing structure (30) defined between the first and second load shoulders; and an extrudable component (32) forming part of the bearing structure. Wherein axial load applied between the first and second bearing assemblies (15, 17) in a first relative axial direction is transmitted between respective pairs of first and second load shoulders via the extrudable components (32) of respective bearing structures (30). The extrudable components (30) provide for load balancing between each bearing stage (14a, 14b).

Abstract: A jarring apparatus includes first and second jarring assemblies which are axially moveable relative to each other between first and second axial configurations, and a thrust assembly interposed between the first and second jarring assemblies to limit relative axial movement therebetween at the second axial configuration and permit axial loading in one axial direction to be transferred between the first and second jarring assemblies via the thrust assembly. The apparatus further includes a jarring mass axially moveable within the jarring apparatus in reverse first and second directions upon relative rotation between the first and second jarring assemblies.

Abstract: A jarring apparatus includes first and second jarring assemblies rotatable relative to each other. A first impact surface is provided on the first jarring assembly and a second impact surface is provided on the second jarring assembly, wherein, in use, the first and second impact surfaces are biased together. A first lifting structure is rotatably fixed relative to the first jarring assembly and a second lifting structure is rotatably fixed relative to the second jarring assembly, the first and second lifting structures being configured to cooperate during relative rotation therebetween to cause cyclical relative displacement in one axial direction to define a lifting phase and relative displacement in a reverse axial direction to define a dropping phase.

Abstract: A jarring apparatus includes first and second jarring assemblies rotatable relative to each other. A first impact surface is provided on the first jarring assembly and a second impact surface is provided on the second jarring assembly, wherein, in use, the first and second impact surfaces are biased together. A first lifting structure is rotatably fixed relative to the first jarring assembly and a second lifting structure is rotatably fixed relative to the second jarring assembly, the first and second lifting structures being configured to cooperate during relative rotation therebetween to cause cyclical relative displacement in one axial direction to define a lifting phase and relative displacement in a reverse axial direction to define a dropping phase.

Abstract: A jarring apparatus includes first and second jarring assemblies which are axially moveable relative to each other between first and second axial configurations, and a thrust assembly interposed between the first and second jarring assemblies to limit relative axial movement therebetween at the second axial configuration and permit axial loading in one axial direction to be transferred between the first and second jarring assemblies via the thrust assembly. The apparatus further includes a jarring mass axially moveable within the jarring apparatus in reverse first and second directions upon relative rotation between the first and second jarring assemblies.

Abstract: A downhole jarring apparatus for use in jarring an object in a bore comprises a first jarring portion including a first impact surface and a second jarring portion including a second impact surface. The apparatus includes a rotatable jarring arrangement operable to translate a rotational drive movement to cause relative axial movement of the first and second impact surfaces to establish axial impact therebetween.