Abstract: A drill string orienting tool for insertion into a well bore includes a housing that has a plurality of inwardly projecting splines. A mandrel is disposed within the housing. The orienting tool has two operating positions, a running position, and an orienting position. The housing is longitudinally moveable relative to the mandrel between the running position and the orienting position. The mandrel and the housing define an annular chamber that is vented to the exterior of the housing. A flexible metallic coiled tube is disposed within the annular chamber and contains hydraulic fluid. The upper end of the coiled tube is coupled to the housing and is in fluid communication with the first fluid chamber. The lower end of the coiled tube is coupled to the mandrel. The mandrel has outwardly projecting splines that are engageable with a corresponding set of inwardly projecting splines on the housing when the orienting tool is in the running position. A piston is movably disposed within the housing.

Abstract: A mechanical-hydraulic double-acting drilling jar includes an inner tubular mandrel telescopingly supported inside an outer tubular housing. The mandrel and the housing each consist of a plurality of tubular segments joined together, preferably by threaded inner connections. Upper and lower pressure pistons are slidably disposed within the housing, respectively closing upper and lower substantially sealed hydraulic chambers. Longitudinal movement of the mandrel engages the collet, which in turn, translates either the upper piston or the lower piston, depending on the direction of mandrel movement. As one of the pistons is moved, fluid pressure builds in the associated hydraulic chamber, retarding further movement of the mandrel, enabling potential energy to build in the drill string.

Abstract: An apparatus is disclosed for use in a drill string 10 to prevent separation of a lower tubular member 16 from an upper tubular member 15 by a rotational force applied from a down-hole motor 22. The down-hole motor 22 is rotated by drilling fluid pumped from the surface, through a passage formed within the drill string 10, and into the down-hole motor 22. A valve 36 is positioned in the passage in the drill string 10 and has a first operating position adapted for passing the drilling fluid to the down-hole motor 22, and a second operating position adapted for substantially blocking the drilling fluid from being delivered through the down-hole motor 22. The value is of a two piece construction, having a first body 44 connected to an upper tubular section 14 and a second body 46 connected to the down-hole motor 22.

Abstract: A down-hole motor and bearing arrangement 22 includes a pair of longitudinally spaced apart bearings 26, 28 that each have multiple rows of ball bearings 36 positioned between a unitary inner race 34 and a two piece outer race 56. The race 34 includes a plurality of longitudinally spaced circumferential grooves 71-73 formed therein, while the outer race 56 includes a plurality of corresponding longitudinally spaced circumferential grooves 77-79 formed on an inner surface thereof. A series of openings 65-67 extend through the outer race 56 and intersect with the circumferential grooves 77-79. The openings 65-67 have a diameter slightly larger than the diameter of the ball bearings 36 but less than the longitudinal width of the grooves 77-79.

Abstract: An accelerator for a fishing jar is disclosed. The accelerator includes front, compression, rear, and air chambers. These chambers insure that the pressure of the fluid in the compression chamber is substantially independent of the temperature of the fluid and the hydrostatic pressure of the well. These chambers also insure that the high pressure seals of the compression chamber are lubricated on each side of each seal. The accelerator also insures that a threshold upward force which is proportional to the hydrostatic pressure must be applied to the drill string before the fluid in the compression chamber begins to be compressed, thereby providing an accelerator that has a higher maximum load in deep wells.

Abstract: The present invention includes a tubular body member with a central bore which has two spiralling or threaded interior surfaces, each interior surface having a leading edge at nearly right angles to the longitudinal axis of the body and a sloped or tapered trailing edge along the bore from an end portion toward the central portion of the bore. The upper portion of the body has a left-hand spiralling or threaded surface. The lower portion of the body has a right-hand spiralling or threaded surface. Inserted into the central portion of the body member from each end is a slip segment or member. The outer surface of the upper slip segment has a left-hand spiralling or threaded surface, whereas the outer surface of the lower slip segment has a right-hand spiralling or threaded surface. Each such spiralling or threaded surface conforms to the spiralling or threaded surface of the corresponding interior surface of the stabilizer body.

Abstract: A slip-on stabilizer is provided for adjustable positioning along a drill collar. The stabilizer includes a body positioned around the drill collar with a threaded section on each end and at least one tapered inner surface with the tapering surface beginning at the end of the interior threads and tapered to a generally narrower interior diameter; a plurality of slip segments with at least one tapered surface complementary matching the tapered surface of the stabilizer body; a locking pin and threaded end caps forcing the slip segment toward the center of the stabilizer body thereby wedging the slip segments against the drill collar by screwing the end cap into the body and thereby clamping the stabilizer body assembly onto the drill collar.

Abstract: An adjustable length drilling sub is disclosed for placing in a drill string between stabilizers to allow the distance between the stabilizers to be changed while the drill string is in the well bore to adjust the rate the angle of the well bore from the vertical is changing. The sub includes an outer member and an inner member that extends into the outer member with an annular space between the members. Protrusions in the form of drive pins mounted in the wall of the outer member extend into the annular space to move into and out of engagement with cavities formed on the outer surface of the inner member. When the pins are in engagement with the cavities, torque in one direction and weight can be transmitted to the bit. When the pins are rotated in the other direction out of the cavities, the members can be moved longitudinally relative to each other to change the distance between the stabilizers.

Abstract: A method of and apparatus for controlling the azimuthal drift of a drill bit in an inclined well bore is described. The method comprises prestressing a drill collar member in torsion to adjust the angle in the horizontal plant that the drill bit makes with the longitudinal axis of the well bore when the drill collar is subjected to the gravitational, axial, and torsional forces of the drilling operation. The drill collar includes an inner tubular member and an outer tubular member. The two are held against relative rotation at one end. The desired torque is placed in the members by rotating the other ends of the members relative to each other in the desired direction. A splined member engages grooves in the inner and outer surfaces of the members to hold the members in their prestressed state.

Abstract: For use in a well jar, a mounting apparatus for resilient elongate snubbers is described. In the preferred and illustrated embodiment, parallel elongate resilient snubbers are formed on metallic backing strips. They are profiled to define sloping elongate sides which slidably fit within undercut grooves. The undercut grooves extend from an encircling shoulder to enable easy insertion into the grooves. The shoulder is adjacent to an encircling narrow neck, thereby enabling an expandable lock ring to be positioned in the neck, securing the resilient snubbers in position.