Development of a cornering water jet drill
Sandia National Laboratories is developing a drilling system which uses high velocity water jets to make horizontal holes in a coal seam accessed through a vertical borehole. For underground coal gasification (UCG), these horizontal holes can be drilled to create linking paths between vertical process wells. During shake-down tests in Albuquerque, five holes were drilled in a simulated coal seam. The 8 to 12 inch (20 to 30 cm) diameter holes deviated from their intended trajectories by less than 12 inches in 20 ft (6.1 m). Similar results have been produced during more recent field tests in an open pit coal mine. An exposed coal seam with undisturbed overburden was penetrated to a depth of 72 ft (21.9 m) with maximum deviations of less than four inches (10.2 cm) vertically and six degrees horizontally. A final proof-of-concept test, in which the seam was accessed from the surface through a vertical borehole, yielded a horizontal hole 50 ft (15.2 m) long with a maximum vertical deviation of +-5 inches (12.7 cm). For all tests to date, the on board logging instrumentation has provided accurate guidance and hole location data. Test results indicate that the drilling system is capable of producing horizontal holes for UCG applications. 11 references, 14 figures.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 6945787
- Report Number(s):
- SAND-83-1837C; CONF-840835-3; ON: DE84015646
- Country of Publication:
- United States
- Language:
- English
Similar Records
Cornering water jet drill for creating horizontal holes in coal seams
Development testing of a cornering water-jet drill
Related Subjects
010404* -- Coal
Lignite
& Peat-- Gasification
42 ENGINEERING
420206 -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
BOREHOLE LINKING
COAL DEPOSITS
COAL GASIFICATION
COAL SEAMS
DATA
DIRECTIONAL DRILLING
DRILLING
DRILLING EQUIPMENT
DRILLS
EQUIPMENT
EXPERIMENTAL DATA
FIELD TESTS
GASIFICATION
GEOLOGIC DEPOSITS
IN-SITU GASIFICATION
IN-SITU PROCESSING
INFORMATION
JET DRILLS
MINERAL RESOURCES
MINING
NUMERICAL DATA
PROCESSING
RESOURCES
SURFACE MINING
TESTING
THERMOCHEMICAL PROCESSES