Casing stabbing and positioning apparatus

Claim 1

A casing stabbing apparatus for engaging swinging, suspended, vertically extending sections of well casing, and maneuvering them into a position to be lowered to the well head which apparatus comprises: a derrick bracket subassembly adapted for selective attachment to a horizontally extending structural member of a derrick adapted for use in the drilling and completion of oil and gas wells, said derrick bracket subassembly comprising: bracket plate means adapted for securement to said horizontally extending derrick structural member at a selected location therealong; a trunnion pedestal connected to said bracket plate means; a lower trunnion plate secured to said trunnion pedestal and having a lower side and an upper side; an upper trunnion plate mounted on the upper side of said lower trunnion plate, and rotatably mounted thereon for rotation about a first vertical axis; means for selectively fixedly securing said upper trunnion plate to said lower trunnion plate at a selected position; and support plate means secured to the upper side of said upper trunnion plate and moveable therewith relative to said lower trunnion plate; a boom housing subassembly detachably and pivotally connected to said upper trunnion plate for pivotation about a first horizontal axis; a boom and jaw subassembly connected to said boom housing subassembly to facilitate pivotation of said boom and jaw subassembly about said first horizontal axis, and to facilitate quick removal of said boom and jaw subassembly and said boom housing subassembly concurrently from said upper trunnion plate during disengagement of said casing stabbing apparatus from said horizontally extending derrick structural member, and to thereby facilitate lowering the disassembled stabbing apparatus downwardly through the interior of the derrick, said boom and jaw subassembly including: an elongated extensible boom having one end connected to said boom housing subassembly, said extensible boom comprising: a stationary hollow sleeve connected to said boom housing subassembly for pivotation about a second vertical axis and with said boom housing subassembly about said first horizontal axis; and an extensible sleeve slidingly and telescopingly engaged with said stationary sleeve for extension and retraction relative thereto of said boom to selectively increase the length thereof; means for selectively extending and retracting said boom comprising: a boom lengthening piston and cylinder subassembly located within the hollow interior of said stationary hollow sleeve and including: a piston rod connected to said extensible sleeve; and a cylinder having an end pivotally connected to said boom housing subassembly for pivotation about common first horizontal and second vertical axes concurrently with the pivotation of said boom about said first horizontal and second vertical axes; a yawing piston and cylinder subassembly for pivoting the boom about said second vertical axis, said yawing piston and cylinder subassembly having one end connected to said boom housing subassembly for pivotation about a third vertical axis; a pair of arcuate casing jaws pivotally mounted on the end of said elongated, extensible boom opposite its end connected to said boom housing subassembly; adjustable roller means carried on said casing jaws for selectively adjusting the diametric dimension defined inside said jaws to thereby facilitate stabbing casing sections of varying dimensions, said adjustable roller means including a plurality of spaced, radially moveable roller elements, easy of said roller elements comprising: a bar slidably mounted in one of said jaws for movement radially inwardly and radially outwardly in the respective jaw in which it is mounted; a roller rotatably mounted in the radially inner side of said bar for undergoing rotation when said roller is in contact with a tubular element passed through, and engaged, by said jaws; and means for adjustably fixing the bar at a selected radial position in the respective bar in which it is mounted; a jaw actuating piston and cylinder subassembly connected between said jaws for selectively pivoting said jaws in converging and diverging movements to facilitate the engagement and disengagement of a section of casing therebetween, said jaw actuating piston and cylinder subassembly connected between said jaws including a jaw actuating cylinder and a jaw actuating extensible piston rod reciprocable in said jaw actuating cylinder for extension in a direction normal to the direction of extension and retraction of said elongated boom, and normal to the longitudinal axis of said elongated extensible boom; and means for pivoting said boom to raise and to lower the end of said boom carrying said jaws, while pivoting the end of said boom connected to said boom housing subassembly about said first horizontal axis.