Abstract: A rotating blowout preventor is comprised of a rotating head assembly which is removably received at the upper end of a main housing. The rotating parts of the head assembly are held fastened together by the provision of a unique locking plate arrangement. An internal bearing chamber is formed within the head assembly and is protected from contamination by an unobvious arrangement of the coacting parts which form the rotating head. The head assembly can rapidly be disassembled without the use of special tools, thereby making field repair of the apparatus possible. The main housing has a replaceable washpipe and seat that likewise is easily field replaceable.

Abstract: Improvements in the operation of a rotating blowout preventor. The rotating head assembly of a rotating blowout preventor includes a stripper rubber which has an upper annular member attached to the lower annular end of a metal support member. The support member extends upwardly into fixed relationship respective to part of the rotating head. The stripper rubber is in the form of an annular body which has an axial passageway formed therethrough for telescopingly receiving a rotating member in sealed relationship therewith. The outer circumferentially extending lower wall surface of the rubber rotatably engages the lower marginal inside wall surface of a fixed washpipe. The present invention provides a positive pressure of drilling media, or drilling media admixed with lubricant, at the interface formed between the outer rubber surface and the inner surface of the washpipe.

Abstract: A rotating blowout preventor having only one moving part which cooperates with an upper bushing to provide resistance to upthrust and downthrust. The apparatus includes provisions for interaction to occur between the rubber of the stripper and the inside peripheral wall surface of the main body in a manner to provide a radial bearing member which resists lateral movement of a driving member received axially through the rotating stripper rubber. The stripper rubber rotates in low friction relationship respective to the remainder of the rotating blowout preventor. The apparatus includes a minimum of moving parts, and therefore is much easier to manufacture, maintain, and operate.

Abstract: Improvements in the rotating head assembly of a rotating blowout preventor. The rotating head assembly includes a stripper rubber which has an upper annular area attached to the lower annular end of a metal support member. The support member extends upwardly into fixed relationship respective to part of the rotating head. The stripper rubber downwardly depends into concentrically arranged, spaced annular body members. The inner annular body has an axial passageway formed therethrough for telescopingly receiving a rotating member in sealed relationship therewith. The outer annular member has an outer circumferentially extending wall surface which rotatably engages the lower marginal end of a fixed washpipe. The inner and outer annular members are made integral respective to the upper annular area of the stripper rubber, and are separated from one another by a downwardly opening annular recess.

Abstract: A rotating blowout preventor having a rotating head to which a stripper assembly is attached. The stripper rubber of the stripper assembly has an axial passageway through which a rotating member is telescopingly received. The stripper rubber has an upper, conical face which downwardly slopes inwardly towards the axial passageway. The stripper assembly is mounted to an annular metal doughnut member having an axial passageway formed therethrough which is slightly larger in inside diameter as compared to the outside diameter of the rotating member extending along the axial centerline of the RBOP. The doughnut has a lower conical face which downwardly slopes inwardly towards the axial centerline of the RBOP, and which is placed closely adjacent to the upper conical face of the stripper rubber.

Abstract: A rotating blowout preventor having a special stripper rubber with reinforcement means incorporated therein in indexed relationship with a kelly drive bushing so that when the kelly is telescopingly received through the rotating blowout preventor, the corners of the kelly drivingly engage both the kelly drive bushing and stripper rubber in indexed relationship therewith. The stripper rubber is provided with spaced-apart reinforcing fingers which sealingly engage the sidewalls of the kelly in an improved manner. The reinforcing fingers are arranged respective to one another to receive the corners of the kelly midway therebetween, so that the kelly outwardly deforms the resilient stripper rubber substantially more at the area which receives the kelly corners as compared to the location of the reinforcing fingers.

Abstract: A rotating blowout preventor of simplified construction which requires no kelly drive bushing, and which has a rotating external housing formed at the upper marginal end thereof within which the main bearings and seals are isolated. The external housing rotates about a fixed washpipe and supports a stripper seal doughnut to which a stripper seal is mounted in underlying relationship thereto. A removal clamp enables the doughnut and stripper rubber to be lifted free of the assembly for service or replacement. The bearing housing is fabricated in a manner to enable servicing the seals and bearings thereof without removing the blowout preventor from the top of a tool string. The bearing housing and seals therefore are arranged respective to the rotating stripper rubber such that should leakage across the stripper rubber and seal occur, the isolated bearing housing will be maintained free of contamination therefrom.

Abstract: Method of going into and coming out of a cased borehole with a toolstring of varying outside diameter wherein the annulus formed between the toolstring and the borehole wall near the casing head must be sealed against fluid flow.The method is carried out by locating a rotatable stripper rubber to the casing head and arranging a second rotatable stripper rubber in spaced superimposed relationship above the first rubber, with the first rubber being larger than the second so as to enable different size tubular goods associated with a drill string to be withdrawn from the borehole, with one of the strippers always sealingly engaging a marginal length of the drill string. Accordingly, the apparatus provides a method of controlling the well pressure during borehole forming operations.Each of the strippers are removably affixed to a rotating sleeve by a quick disconnect means in the form of a circumferentially extending hinged clamp means.

Abstract: A rotary drilling head assembly having a main body through which an axial bore is formed for sealingly receiving, in an axially rotatable and longitudinally slidable manner, a driving member therethrough, thereby enabling the driving member to be moved longitudinally respective to the head while it is being axially rotated by the turntable.An outflow passageway conducts fluid flow away from the head, while a second seal means controls fluid flow between the relative rotating parts of the assembly.