Jerry Mack Griffith

US Patent:

51390868, Aug 18, 1992

Filed:

Jun 19, 1990

Appl. No.:

7/541046

Inventors:

Jerry M. Griffith - Scott LA

Assignee:

Grifco, Inc. - Scott LA

International Classification:

E21B 31107

US Classification:

166178

Abstract:

A combined accelerator, for accumulating energy, and jar, for sudden release of accumulated energy, for delivering up or down jarring impacts to objects stuck downhole in a wellbore, includes upper and lower tubular members which are telescopically connected within an integral outer tubular housing. The upper tubular member is connected to a pipe or tubing string inserted into the wellbore and cooperates with the outer tubular housing through mechanical spring means so as to accumulate a selected amount of energy to be released as a jarring impact. The lower tubular member is connected to the stuck object and cooperates with the outer housing through spring biased, tapered latch bars, so as to provide a sudden energy releasing means. A threaded adjusting bushing is provided within the outer housing so as to allow selection of a desired amount of spring bias, imposed on the latch bars, thereby providing a convenient field means for controlling the amount of jarring impact imparted to the stuck object.

US Patent:

53300181, Jul 19, 1994

Filed:

May 6, 1993

Appl. No.:

8/058870

Inventors:

Jerry Griffith - Scott LA

International Classification:

E21B 31107

US Classification:

175299

Abstract:

An automatic set bi-directional apparatus for jarring an object in a well bore is disclosed. The apparatus comprises a tubular member having a portion defining an upper and lower striking shoulder, said tubular member having one end connected to a work string capable of creating a longitudinal force. A mandrel is connected to the object and the mandrel is concentrically disposed within said tubular member. The apparatus further includes a plurality of elongated members and an upper and lower ring members which serve as latch means. The mandrel further comprises a first and second grooved portion which are used for releasing the tubular member in order to deliver either an upward or downward jarring impact upon a stationary anvil.

Author:

Jerry Griffith

ISBN #:

0252013263

Author:

Jerry Griffith

ISBN #:

0136653987

Author:

Jerry Griffith

ISBN #:

0817305505

Author:

Jerry Griffith

ISBN #:

0817305513

Author:

Jerry Griffith

ISBN #:

0850133173

Author:

Jerry Griffith

ISBN #:

0879851023

Author:

Jerry Griffith

ISBN #:

0897747267

Author:

Jerry Griffith

ISBN #:

0960639209