Abstract: A mud saver valve comprising a tubular body connectable between a kelly and a drill string. A piston is mounted therein and includes a bore substantially coaxially aligned with the central opening. A plug is removably mounted in the piston and is movable between a first position wherein a spear sealingly engages the valve seat and a second position that allows fluid to flow upward between the spear and the valve seat. The piston is constructed with an elongate intermediate body section having a plurality of O-rings secured therein and disposed beneath angled ports for enhancing lateral stability of the piston within the body. The valve seat is furthermore secured within the body by a spanner ring with the valve seat being formed with a curved mating surface adapted for flushly engaging a curved valve seat surface of a valve seat disposed upon the piston. Both the upper and lower valve seats are removable for field repair while axially actuatable with lateral stability.

Abstract: Well bore tools configured as centralizers/stabilizers, well bore reamers, and keyseat wipers each of which includes an elongate tubular body having a generally cylindrical outer surface and a diameter approximately equal to the diameter of the borehole being drilled. Each tool affords an improved mode of drilling a borehole by increasing downhole directional control and stability, increasing tool wear reliability, and reducing return mud flow resistance. The outer surface of each tool has a plurality of longitudinal passages formed in pairs of upright intersecting right and left hand helicies or spirals about the exterior of said tool and extending from one end to the other end thereof. The intersecting right and left hand helical or spiral channels form raised pad areas therebetween to provide 360.degree. contiguous well bore contact by each tool for enhanced stability and efficiency.

Abstract: A shock absorber from an oil well drill string mounted therein adjacent its drill bit to cushion drill bit impacts in hard formations and having an elongate tubular mandrel, for connection with said bit, slidably mounted in and drivingly connected to an elongate tubular housing coupled in the drill string. Tubular housing is composed of upper, intermediate and lower tubular sections, preferably; the uppermost has a bore complementary to and slidably engaged by upper packing means on upper end of mandrel, intermediate section has a bore complementary to and in slidable engagement with the mandrel and the lowermost has an upper bore complementary to and slidably engaged by downwardly biased lower packing means slidably confined upon mandrel and a lower bore complementary to mandrel with slidable drive connection between mandrel and housing therein.

Abstract: A hydraulic junk retriever having a tubular mandrel for connection and communication with a drill pipe and rotatably suspending an elongate cylindrical housing within a well bore. A flow passage in the upper end of the housing communicates with bore of the mandrel and has one or more ports extending outwardly at a tangent to the cylindrical interior of the passage for discharging or jetting drilling fluid under pressure tangentially into the well bore so as to impart rotation to said housing and centrifugal force to the drilling fluid. Preferably, the tangential discharge ports are downwardly inclined whereby the circular motion of the fluid becomes helical so as to direct said fluid to the bottom of the well bore at which the lower end of the housing is disposed.