Method and system for displacing drilling fluid from a drill string in a well drilling system

Patent · Tue Mar 25 04:00:00 EST 1986

OSTI ID:5782074

Dellinger, T B; Boston, W G; Sexton, J H; Strong, R T

This patent describes a method of rotary drilling of a wellbore with a drill string, formed with sections of drill pipe, and having a drill bit at the lower end thereof, the method of disconnecting and breaking out at least one section of drill pipe from the drill string at a select drill string joint with minimized drilling fluid spillage, it consists of the steps of (a) pulling the drill string out of the wellbore, (b) continuously rotating the drill string with a top drive drilling motor and circulating drilling fluid through the drill string while the drill string is being pulled from the wellbore, (c) stopping the drill string rotation and the drilling fluid circulation when a select drill string joint is above the drilling rig floor, (d) injecting compressed gas into the drill string to displace the drilling fluid in that portion of the drill string above the select drill string joint, (e) stopping the injection of compressed gas into the drill string when the drilling fluid level has fallen below the select drill string joint, and (f) breaking out that portion of the drill string above the selected drill string joint.

• Assignee: Mobil Oil Corp., New York, NY
• Patent Number(s): US 4577700
• OSTI ID: 5782074
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
CABLES
COMPRESSED GASES
CONTROL EQUIPMENT
DRILL BITS
DRILL PIPES
DRILLING
DRILLING EQUIPMENT
DRILLING FLUIDS
EQUIPMENT
FLOW REGULATORS
FLOWMETERS
FLUIDS
GASES
MEASURING INSTRUMENTS
METERS
MOTION
MOTORS
OIL WELLS
PIPES
ROTARY DRILLING
ROTATION
TORQUE
VALVES
WELL DRILLING
WELLS