Alex Dufrene

US Patent:

39603997, Jun 1, 1976

Filed:

Dec 16, 1974

Appl. No.:

5/532996

Inventors:

Alex Dufrene - Des Allemands LA

International Classification:

E21B 3102

US Classification:

294 8625

Abstract:

A setting and retrieval device for down-hole equipment which includes a solid mandrel tapered at its bottom to a larger diameter which cooperates with a set of surrounding collet fingers which have a shoulder and gripping threads thereon to engage a fish or a tool to be set down hole. The apparatus is used as a running tool and a retrieval tool. The collet fingers slide relative to the taper at the urging of a compressible spring arranged between a slidable thimble which supports the collet fingers. It is locked in the up position by serrations which face one another.

US Patent:

40444708, Aug 30, 1977

Filed:

Jan 15, 1976

Appl. No.:

5/649440

Inventors:

Alex Dufrene - Des Allemands LA

International Classification:

E21B 4704
G01B 518

US Classification:

33125R

Abstract:

A collar locating apparatus is disclosed. It is a wire line tool adapted to be run in a tubing string to count the number of collars and thereby determine depth. It incorporates an elongate body. It has a pair of caliper arms which are spring loaded to flare outwardly. The device is run to the bottom of the tubing string and is jar operated to sever a shear pin whereupon the caliper arms are released to deflect outwardly. The extent of deflection of the arms is determined by an adjustable nut below the arms which slides downwardly on the body and releases the arms for controlled outward deflection. The arms are pivoted and clamped at a common collar above the arms to enable them to pivot.

US Patent:

41272978, Nov 28, 1978

Filed:

Dec 6, 1976

Appl. No.:

5/748109

Inventors:

Alex Dufrene - Des Allemands LA

International Classification:

E21B 3100

US Classification:

294 862

Abstract:

A wireline operated overshot is disclosed. In the illustrated embodiment, the overshot includes a grapple which is located internally of a sleeve telescoped about it having a tapered internal shoulder. The grapple engages and disengages a fish. In the event the overshot becomes stuck on a fish, it can be released by downwardly jarring movement which shears a pin. The pin is located to permit a limited range of telescoping movement between the grapple and telescoped external sleeve. A spring is incorporated which forces the grapple downwardly against the tapered sleeve. The apparatus includes a latching mechanism which overcomes the spring to move the parts to a released position.