1
William N Schoeffler: Valved jet device for well drills. Pioneer Fishing and Rental Tools, John D Jeter, October 7, 1986: US04615399 (35 worldwide citation)

A column of drill collars have holes or jets extending radially from the collar bore through the collar wall. A wash pipe extends full length through the bore of the perforated collars, so sized as to leave an annular flow space between the wash pipe and the collar bore wall. A remote control select ...


2
Thomas E Falgout Sr, William N Schoeffler: Fluid Powered drilling jar. Pioneer Fishing and Rental Tools, John D Jeter, February 28, 1989: US04807709 (7 worldwide citation)

A hydraulic drill string jar is powered and actuated by drilling fluid pressure controlled from the earth surface. By selective manipulation of drilling fluid flow, the jar can be conditioned to operate in drilling mode to avoid activation of the jars while normal drilling and fluid flow activities ...