Thomas J Langston

US Patent:

52371360, Aug 17, 1993

Filed:

Oct 21, 1991

Appl. No.:

7/779650

Inventors:

Thomas J. Langston - New Iberia LA

International Classification:

H01H 3538
E21B 43116
F42C 1500

US Classification:

200 81R

Abstract:

In accordance with illustrative embodiments of the present invention, a safety bypass switch for use with explosive well tools includes a hollow conductive body having a copper conductor rod extending axially therethrough, a spring-loaded contact element movable transversely in the body between a first position where a surface of the element engages the rod to provide a solid short between the rod and the body, and a second position where such surface is out of engagement with the rod, and a diaphragm or piston for operating the contact element in a manner such that a predetermined hydrostatic pressure in the well bore will shift the contact element to the second position. The springs which bias the element toward the first position are mounted internally and externally of the body. In another embodiment of the invention a manually operated grounding switch is used in combination with the hydrostatic pressure operated switch to provide redundant assurance against accidental firing.

US Patent:

49670484, Oct 30, 1990

Filed:

Feb 22, 1990

Appl. No.:

7/483355

Inventors:

Thomas J. Langston - New Iberia LA

International Classification:

E21B 43116
F42C 1500
H01H 3538

US Classification:

200334

Abstract:

In accordance with illustrative embodiments of the present invention as disclosed herein, a safety switch for preventing accidental firing of an explosive well tool includes a tubular metal body connected between the cable head and the well tool, a conductor wire extending through such body for carrying current from the cable to the well tool, and a contact plug mounted in a slide opening in the body and arranged to be selectively advanced into shorting contact with the conductor wire.

US Patent:

51314657, Jul 21, 1992

Filed:

Nov 23, 1990

Appl. No.:

7/617211

Inventors:

Thomas L. Langston - New Iberia LA

Assignee:

Arrow Electric Line, Inc. - Lafayette LA

International Classification:

E21B 43117

US Classification:

166 551

Abstract:

In accordance with an illustrative embodiment of the present invention, a perforating gun apparatus for forming holes in a well casing through which cement can be circulated includes a mandrel, four arm-mounted, shaped charge carriers on the body, and bow springs on the body in the plane of each carrier for biasing the carriers outward into sliding contact with the well casing. The charges form evenly distributed series of vertically arranged holes the casing, without damage to an outer casing string, so that cement can be circulated through the holes and into the annulus without channeling.

US Patent:

51654890, Nov 24, 1992

Filed:

Feb 20, 1992

Appl. No.:

7/838035

Inventors:

Thomas J. Langston - New Iberia LA

International Classification:

E21B 43112

US Classification:

175 454

Abstract:

In accordance with illustrative embodiments of the present invention, a hydrostatic pressure-responsive safety sub that prevents firing of an explosive well tool until it has been lowered below a predetermined depth in a fluid-filled well bore includes a body having an upper chamber that houses a detonator and a lower chamber that houses a booster which is attached to a primercord. A passageway between these chambers normally is blocked by an inner portion of a spring-loaded, hydrostatic pressure-responsive piston which is shifted inward against the bias of a combination of springs. When the explosive tool has been lowered to a predetermined depth in the well, a bore in the piston becomes aligned with the passageway between the chambers so that explosive forces generated by explosion of the detonator can reach the booster.

Author:

Thomas J. Langston

ISBN #:

0805963677

Author:

Thomas S. Langston

ISBN #:

0801843618

Author:

Thomas S. Langston

ISBN #:

0801850169

Author:

Thomas S. Langston

ISBN #:

0801855101

Author:

Thomas S. Langston

ISBN #:

0801874211