Skirted hammer sub for dual tube drilling

Patent · Tue Jun 23 04:00:00 EDT 1981

OSTI ID:6161170

Ford, G A; Willis, C A

A skirted crossover sub for joining an air hammer to a string of dual concentric drill pipe is characterized by passageways for directing air from the pipe string annulus to operate the hammer and for directing exhaust air and cuttings from the hammer bit to the inner pipe of the string. A tubular skirt at the downhole end of the sub surrounds the hammer and channels the flow of exhaust air therebetween. A packer and uphole reamer may be included, as well as valves for air lift and for providing proper air flow direction in the borehole annulus.

• Assignee: Walker Neer Manufacturing Co Inc
• Patent Number(s): US 4274497
• OSTI ID: 6161170
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000 -- Coal
Lignite
& Peat-- Mining
02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
04 OIL SHALES AND TAR SANDS
040300 -- Oil Shales & Tar Sands-- Drilling
Fracturing & Mining
42 ENGINEERING
420206 -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
CONTROL EQUIPMENT
DESIGN
DRILL PIPES
DRILLING EQUIPMENT
EQUIPMENT
FLOW REGULATORS
MINING EQUIPMENT
OIL WELLS
PIPES
VALVES
WELLS