Earth boring drill
The described well drilling and coring apparatus uses dual passage drill pipe with a choke snugly embracing a core being cut to block fluid flow up the core tube and divert it to the hole annulus. Scavenging of cores and cuttings up through the core tube is accomplished by diverting a portion of the circulating fluid into the core tube through a series of ports above the bit. Gas drilling is facilitated by a series of normally open, diaphragm- operated valves between flow passages to that gas pumped down one passage will force fluid up the other. The fluid head in the other passage approximately balances the gas pressure, but when it falls below the level of the valve, the valve is closed by the higher pressure in the gas flow passage. (14 claims)
- Assignee:
- TUL; EDB-81-089790
- Patent Number(s):
- US 3338322
- OSTI ID:
- 6369041
- Country of Publication:
- United States
- Language:
- English
Similar Records
Method for drilling and coring
Method for lubricating an unsealed boring bit