Rotary drilling techniques used in the Beckley coalbed

Book · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7160936

Goodman, T W

Bureau of Mines used a contact drilling strategy with short-collared assemblies in order to rotary drill long horizontal methane drainage holes in the Beckley Coalbed near Glen Daniel, WV. By decreasing the thrust and increasing the rotation of the drill bit when in contact with the roof and floor rock, assemblies with 1-ft (0.3-m), 10-ft (3-m), and 14-f (4.3m) long collars were made to deflect and stay in the coalbed. Successful application of this procedure resulted in holes drilled full length in coal with the original assembly including bit. The test assemblies deflected away from the original bearings of the holes during drilling and arced. Four holes were drilled to depths ranging from 478 ft (145.7m) before the strategy was developed, to 4,034 ft (1,230m) when the strategy was applied. Total length of the holes in coal was 8,590 ft (2,618m). After 577 days the total methane captured by the holes was 221,600,000 ft{sup 3} (6,276,000 m{sup 3}). The methane flow rate peaked at 805,000 ft{sup 3}/d(2,798 m{sup 3}/d), then decreased to stabilize at 670,000 ft{sup 3}/d(18,974 m{sup 3}/d) after 6 months.

• OSTI ID: 7160936
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012033* -- Coal
Lignite
& Peat-- Underground Mining-- Mine Environment-- (1987-)
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
ALKANES
COAL DEPOSITS
COAL SEAMS
DEGASSING
DRILLING
DRILLING EQUIPMENT
DRILLS
EQUIPMENT
GEOLOGIC DEPOSITS
HYDROCARBONS
MECHANICS
METHANE
MINERAL RESOURCES
ORGANIC COMPOUNDS
REMOVAL
RESOURCES
ROCK DRILLING
ROCK MECHANICS
ROTARY DRILLING
ROTARY DRILLS