Assignee
CHRISTENSEN INC
48 patents
Top patents by PatentIndex Score
US4373593AFeb 15, 1983
Drill bit
CHRISTENSEN INC212 citations99
US4351401ASep 28, 1982
Earth-boring drill bits
CHRISTENSEN INC216 citations99
US4429741AFeb 7, 1984
Self powered downhole tool anchor
CHRISTENSEN INC266 citations98
US4471845ASep 18, 1984
Rotary drill bit
CHRISTENSEN INC92 citations96
US4452324AJun 5, 1984
Rotary drill bit
CHRISTENSEN INC60 citations96
US4415823ANov 15, 1983
Generator for the production of electrical energy
CHRISTENSEN INC56 citations96
US4234048ANov 18, 1980
Drill bits embodying impregnated segments
CHRISTENSEN INC62 citations96
US4186569AFeb 5, 1980
Dual spring drill string shock absorber
CHRISTENSEN INC80 citations96
US4244432AJan 13, 1981
Earth-boring drill bits
CHRISTENSEN INC71 citations95
US4133516AJan 9, 1979
Shock absorber for well drilling pipe
CHRISTENSEN INC72 citations95
US4092881AJun 6, 1978
Apparatus for making-up and breaking threaded pipe connections
CHRISTENSEN INC66 citations95
US4515227AMay 7, 1985
Nozzle placement in a diamond rotating bit including a pilot bit
CHRISTENSEN INC63 citations94
US4073354AFeb 14, 1978
Earth-boring drill bits
CHRISTENSEN INC106 citations94
US4460053AJul 17, 1984
Drill tool for deep wells
CHRISTENSEN INC117 citations93
US4200159AApr 29, 1980
Cutter head, drill bit and similar drilling tools
CHRISTENSEN INC195 citations93
US4098363AJul 4, 1978
Diamond drilling bit for soft and medium hard formations
CHRISTENSEN INC71 citations93
US4512419AApr 23, 1985
Coring device with an improved core sleeve and anti-gripping collar
CHRISTENSEN INC27 citations92
US4468762AAug 28, 1984
Telemetry equipment in modules
CHRISTENSEN INC49 citations92
US4440246AApr 3, 1984
Cutting member for rotary drill bits
CHRISTENSEN INC44 citations92
US4415316ANov 15, 1983
Down hole motor
CHRISTENSEN INC50 citations92
US4391328AJul 5, 1983
Drill string safety valve
CHRISTENSEN INC53 citations92
US4356872ANov 2, 1982
Downhole core barrel flushing system
CHRISTENSEN INC35 citations92
US4352400AOct 5, 1982
Drill bit
CHRISTENSEN INC86 citations92
US4256192AMar 17, 1981
Pressure core barrel
CHRISTENSEN INC43 citations92
US4194582AMar 25, 1980
Double acting shock absorbers for drill strings
CHRISTENSEN INC50 citations92
US4187061AFeb 5, 1980
Rotary helical fluid motor with deformable sleeve for deep drilling tool
CHRISTENSEN INC48 citations92
US4011918AMar 15, 1977
Stabilizer for drill strings
CHRISTENSEN INC38 citations92
US4499959AFeb 19, 1985
Tooth configuration for an earth boring bit
CHRISTENSEN INC84 citations90
US4361194ANov 30, 1982
Bearing system for a downhole motor
CHRISTENSEN INC32 citations90
US4266621AMay 12, 1981
Well casing window mill
CHRISTENSEN INC112 citations90
US4278138AJul 14, 1981
Composite heavy metal drill collar
CHRISTENSEN INC36 citations89
US4512426AApr 23, 1985
Rotating bits including a plurality of types of preferential cutting elements
CHRISTENSEN INC90 citations86
US4512425AApr 23, 1985
Up-drill sub for use in rotary drilling
CHRISTENSEN INC41 citations86
US4310059AJan 12, 1982
Composite heavy metal drill collar
CHRISTENSEN INC35 citations86
US4499563AFeb 12, 1985
Apparatus for transmitting data from a borehole to the surface of the earth during the operation of a drilling device
CHRISTENSEN INC23 citations82
US4452322AJun 5, 1984
Drilling device for drilling a core in deep drill holes
CHRISTENSEN INC21 citations82
US4270569AJun 2, 1981
Valve assembly for the remote control of fluid flow having an automatic time delay
CHRISTENSEN INC56 citations82
US4265323AMay 5, 1981
Direct bit drive for deep drilling tools
CHRISTENSEN INC22 citations82
US4245709AJan 20, 1981
Removable drill string stabilizers
CHRISTENSEN INC50 citations82
US4231437ANov 4, 1980
Combined stabilizer and reamer for drilling well bores
CHRISTENSEN INC49 citations82
US4081043AMar 28, 1978
Hydraulic jars for bore hole drilling
CHRISTENSEN INC19 citations82
US4252102AFeb 24, 1981
Cutting element for processing rocks, metal or the like
CHRISTENSEN INC25 citations81
US4336850AJun 29, 1982
Internal fluid screen to prevent nozzle and port plugging
CHRISTENSEN INC17 citations74
US4537097AAug 27, 1985
Method and apparatus for manufacturing cutting elements particularly for deep drilling
CHRISTENSEN INC17 citations73
US4463815AAug 7, 1984
Mechanical jarring tool
CHRISTENSEN INC18 citations71
US4512423AApr 23, 1985
Coring device with an improved weighted core sleeve and anti-gripping collar
CHRISTENSEN INC17 citations70
US4272987AJun 16, 1981
Pressure core barrel flushing system
CHRISTENSEN INC15 citations66
US4275528AJun 30, 1981
Electroplated diamond milling cutter
CHRISTENSEN INC12 citations59