Method and apparatus for controlling hydrostatic pressure gradient in offshore drilling operations

Patent · Tue Jun 11 04:00:00 EDT 1974

OSTI ID:5006025

Bruce, G H; Ilfrey, W T

A system for offshore drilling is described which is useful in those operations where a floating vessel is situated at the surface of a body of water and circulation of drilling fluid is accomplished by introducing drilling fluid into a drill string extending from the vessel into a borehole in the floor of the body of water and returning it through a separate conduit to the vessel. A surface detectable signal is generated which is proportional to the hydrostatic head exerted by the drilling fluid within the return conduit. Hydrostatic head of the drilling fluid within the return conduit is controlled in response to the signal, by injecting gas into the conduit near its lower end, to regulate the hydrostatic head of the fluid in the borehole. (2 claims)

• Assignee: Esso Production Res. Co.
• Patent Number(s): US 3815673
• OSTI ID: 5006025
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
42 ENGINEERING
423000 -- Engineering-- Marine Engineering-- (1980-)
BOREHOLES
CAVITIES
CONTROL
DESIGN
DRILLING
DRILLING EQUIPMENT
DRILLING FLUIDS
EQUIPMENT
FLUIDS
HYDROSTATICS
NATURAL GAS WELLS
OFFSHORE DRILLING
OIL WELLS
PRESSURE GRADIENTS
RECYCLING
WELLS