Pub. Number: US7185719
Appl. Data: 10 20040210
Applicant: Shell Oil Company
Inventor: van Riet, Egbert Jan
Title: Dynamic annular pressure control apparatus and method
A drilling system for drilling a bore hole into a subterranean earth formation, wherein at least a portion of the mud flow from the primary mud pump is diverted to the mud discharge outlet, thereby creating a backpressure system to readily increase annular pressure.