Rotatable reciprocating collar for borehole casing

Patent · Tue Jul 07 04:00:00 EDT 1987

OSTI ID:6150106

Blandford, D M; Easter, J H

This patent describes a rotatable reciprocating collar for series connection into a borehole casing string between an upper segment and a lower segment of the casing string to assist in a multistage cementing operation. Means is provided for passing cement from the interior of the casing string to the annulus between the casing string and borehole proximate the collar, comprising: an open cylindrical barrel having a first barrel end, a second barrel end, and an inner surface; barrel splines project radially inward from the inner surface at the first barrel end; an open cylindrical mandrel has a first mandrel end, a second mandrel end, and an outer surface; mandrel splines project radially outward from the outer surface at the first mandrel end; the mandrel is slidably disposed within the barrel such that the second mandrel end is telescopically extendable from the first barrel end; the mandrel splines engage the barrel splines when the second mandrel end is telescopically extended from the first barrel end and the mandrel splines disengage the barrel splines when the mandrel is telescopically retracted into the barrel; and the second barrel end is connected to one of the segments of the casing string and the second mandrel end connected to the other of the segments to permit rotation and reciprocation of the upper segment relative to the lower segment during a multistage cementing operation. The collar remains permanently within the borehole after cementing to form a portion of the casing.

• Assignee: NOV; EDB-87-146508; NOV-87-072115
• Patent Number(s): US 4678031
• OSTI ID: 6150106
• 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
420206 -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
BOREHOLES
BUILDING MATERIALS
CAVITIES
CEMENTING
CEMENTS
CONDUCTOR DEVICES
CONNECTORS
DRILL BITS
DRILL PIPES
DRILLING
DRILLING EQUIPMENT
ELECTRICAL EQUIPMENT
EQUIPMENT
MATERIALS
MOTION
NATURAL GAS WELLS
OIL WELLS
PIPES
ROTATION
WELL CASINGS
WELL DRILLING
WELLS