Jar tool

Patent · Tue Oct 23 04:00:00 EDT 1984

OSTI ID:6396247

Tomm, W R; Ring, C

A jar tool for use in a drill string for use in dislodging a drill bit or well-tools trapped in well bores. The tool comprises an outer housing adapted to move longitudinally with respect to an inner spline mandrell. A piston assembly is acted on by a piston actuator and hydraulic fluid restricts the movement of the piston assembly and, therefore, the movement of the mandrell relative to the housing, while the piston assembly is within a narrower portion of a hydraulic cylinder. When the piston assembly reaches a larger diameter portion of the cylinder, the hydraulic fluid rushes past the piston assembly which allows a knocker connected to the spline mandrell to collide with the outer housing. A compression spring returns the piston assembly to its rest position abutting a shoulder on the outer housing. Provision is made for pressure release valves to be inserted in the piston assembly so that the tool can be operated within minimum and maximum operating limits.

• Assignee: Bralorne Resources Limited (Canada)
• Patent Number(s): US 4478284
• OSTI ID: 6396247
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
ACTUATORS
CONTROL EQUIPMENT
COVERINGS
CYLINDERS
DESIGN
DRILL BITS
DRILL PIPES
DRILLING EQUIPMENT
EQUIPMENT
FLOW REGULATORS
HYDRAULIC EQUIPMENT
MACHINE PARTS
NATURAL GAS WELLS
OIL WELLS
PIPES
PISTONS
RELIEF VALVES
REMOVAL
SPRINGS
VALVES
WELLS