Title: Method of assembling multiple wall drill pipe

Abstract: Multiple wall drill pipe adapted for use in a drill pipe string comprising an outer pipe member; an inner pipe member disposed within the outer pipe member; and means for releasably connecting the inner pipe member and the outer pipe member in fixed axial relationship under force loads applied in use during a drilling operation while enabling relative rotary movement between the inner pipe member and the outer pipe member during a rotary drilling operation to relieve torsional stress thereon, and for permitting the removal of the inner pipe member from the outer pipe member by relative axial displacement therebetween caused by application to the inner pipe member of only an axially directed force load in excess of the axially directed force loads applied to the inner pipe member in use during a normal drilling operation.

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Other info:

Inventors: Becker, Floyd W. (Calgary, CA)
Regimbal, Richard R. (Calgary, CA)

Application Number: 06/166143
Filing Date: 1980-07-07
Publication_date: 1982-07-06
Assignee: DRILL SYSTEMS INC

Primary Class(es): 29/451 29/455.100, 138/148, 175/215, 277/323
Other Classes: B23P11/02; E21B17/18; E21B17/00; B23P11/02
US Patent Ref:

1930285	October, 1933	Robinson	138/148
2738992	March, 1956	Heisler	29/451
2895512	July, 1959	Forsyth et al.	138/148
3332446	July, 1967	Mann	138/148
3487534	January, 1970	Schustack	285/18
3503636	March, 1970	Bower	285/305
3552778	January, 1971	Muller	285/276
3639972	February, 1972	Schelin et al.	29/451

Other Refs:
Primary Examiner: Moon, Charlie T.
Assistant Examiner:
Attorney: Klaas, Bruce G.

Parent Case Data:

This is a division of application Ser. No. 890,068, filed Mar. 27, 1978, now U.S. Pat. No. 4,274,663, is