|
US4637462A
|
|
Liquid mud ring control of underground liquids
|
|
US4585274A
|
|
Mineral and metal particle recovery apparatus and method
|
|
US4497519A
|
|
Metal particle recovery at sub-surface locations
|
|
US4071085A
|
|
Well head sealing system
|
|
US4024913A
|
|
Well installations employing non-metallic lines, tubing casing and machinery
|
|
US2891342A
|
|
Net type fishing apparatus
|
|
US2850264A
|
|
Dual passage concentric pipe drill string coupling
|
|
US2663545A
|
|
Method and apparatus for well drilling and testing
|
|
US2701122A
|
|
Method and apparatus employing compressed gas for drilling wells
|
|
US2641927A
|
|
Well pipe vibrating apparatus
|
|
US2657016A
|
|
Fluid circulation head for drill strings
|
|
US2479740A
|
|
Pipe-joint retainer
|
|
US2586939A
|
|
Directed well drilling
|
|
US2522444A
|
|
Well fluid control
|
|
US2509144A
|
|
Well plugging and whipstocking
|
|
US2453369A
|
|
Pipe tongs
|
|
US2311225A
|
|
Pipe rotating apparatus
|
|
US2257337A
|
|
Dental amalgamator
|
|
CA542067A
|
|
Method and apparatus employing compressed gas for drilling wells
|
