Design considerations for a hard-rock PDC drill bit

Conference · Mon Aug 26 00:00:00 EDT 1985

OSTI ID:5747583

Glowka, D A

This paper discusses the potential for developing a polycrystalline diamond compact (PDC) drill bit for hard-rock applications such as geothermal drilling. It is concluded that in order to use the inherently efficient drag cutting process in such severe applications, measures must be taken to reduce cutter penetrating forces in order to prevent thermally-accelerated cutter wear and thereby improve bit life. A procedure is developed for determining the conditions under which waterjets can be effectively used for this purpose by directing them at the rock surface ahead of individual cutters. It is concluded that hard rocks with compressive strengths as high as 30 kpsi (200 MPa) may be drillable with a hybrid PDC/waterjet bit using pressures that conventional oil field pumping technology is capable of providing. Extremely hard rocks might be drilled with such a bit using nozzle pressures well below those required to effectively cut the rock with waterjets alone. 13 refs., 6 figs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5747583
• Report Number(s): SAND-85-0666C; CONF-850801-2; ON: DE85008313
• Resource Relation: Conference: International symposium on geothermal energy, Kailua Kona, HI, USA, 26 Aug 1985
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
DRILL BITS
DESIGN
CRACK PROPAGATION
DIAMONDS
GEOTHERMAL WELLS
JET DRILLS
ROTARY DRILLS
WELL DRILLING
CARBON
DRILLING
DRILLING EQUIPMENT
DRILLS
ELEMENTAL MINERALS
ELEMENTS
EQUIPMENT
MINERALS
NONMETALS
WELLS
Geothermal Legacy
150901* - Geothermal Engineering- Drilling Technology & Well Hardware