Claims
- 1. An insulating drill collar joint, including:
- a first metallic drill collar segment having a first threaded section with a coating of electrically insulating ceramic material thereon;
- said insulating coating being in the range of from 0.002 to 0.006 inch thick; and
- a second metallic drill collar segment connected to said first drill collar segment, said second drill collar segment having a second threaded section threadably engaged with the insulation coated threaded section of said first drill collar section whereby an electrically insulated drill collar joint is formed.
- 2. The insulated drill collar joint of claim 1 wherein:
- said coating of ceramic material is applied by a detonation gun process.
- 3. The insulated drill collar joint of claim 1 wherein:
- said first threaded section is reduced in thickness from its normal dimension by an amount equal to the thickness of said ceramic coating.
- 4. The insulated drill collar joint of claim 1 wherein:
- said ceramic coating is aluminum oxide.
- 5. The insulated drill collar joint of claim 1 including:
- a coating of sealer on said ceramic material wherein said sealer coating is effective to reduce porosity.
- 6. The insulated drill collar joint of claim 5 wherein:
- said coating of ceramic material is applied by a detonation gun process.
- 7. The insulated drill collar joint of claim 5 wherein:
- said first threaded section is reduced in thickness from its normal dimension by an amount equal to the thickness of said ceramic coating.
- 8. The insulated drill collar joint of claim 5 wherein:
- said ceramic coating is aluminum oxide.
Parent Case Info
This application is a division of application Ser. No. 572,801, filed Jan. 23, 1984.
US Referenced Citations (16)
Foreign Referenced Citations (2)
Number |
Date |
Country |
2706624 |
Aug 1978 |
DEX |
1437587 |
May 1976 |
GBX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
572801 |
Jan 1984 |
|