05355967 is referenced by 180 patents and cites 12 patents.

A method for rotary drilling and removing cuttings provides a underbalanced drilling fluid pressure at the drilling face but overbalanced pressure in the wellbore. The preferred method uses a rotary drill within a housing which also encloses a jet pump which draws and pressurizes the cuttings and drilling fluid, a separator of the cuttings and a portion of the pressurized drilling fluid, and a nozzles to supply separated and reduced pressure drilling fluid back to drilling face while the cuttings and remaining pressurized drilling fluid flows up towards the surface. The method avoids overpressure strengthening of the drill face and underpressure damage to the wellbore.

Title
Underbalance jet pump drilling method
Application Number
7/969018
Publication Number
5355967
Application Date
October 30, 1992
Publication Date
October 18, 1994
Inventor
William O Jacobson
San Diego
CA, US
Mark D Mueller
Bakersfield
CA, US
Agent
William O Jacobson
Gregory F Wirzbicki
Assignee
Union Oil Company of California
CA, US
IPC
E21B 10/60
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