David E Nagel

US Patent:

44961740, Jan 29, 1985

Filed:

Jan 30, 1981

Appl. No.:

6/229800

Inventors:

William J. McDonald - Houston TX
William C. Maurer - Houston TX
David D. Nagel - Houston TX

Assignee:

Tele-Drill, Inc. - Richardson TX

International Classification:

F16L 1112

US Classification:

285 53

Abstract:

An insulated drill collar gap sub assembly for a toroidal coupled telemetry system including a first annular sub member (150) operable to be connected at one end to a drill collar and a second annular sub member (156) operable to form a part of a drill collar sub. The first and second annular sub members have interconnecting structural members (54, 58) operable to structurally interfere. The interconnecting structural members are dimensioned to form a continuous gap (160) between mutually opposing surfaces and a dielectric material (162) fills the gap to electrically isolate the first annular sub member with respect to the second annular sub member. A bearing member (164) is positioned between the first annular member and the second annular member and is coated with a dielectric insulation (166) to facilitate the formation of a drill collar gap sub assembly of structural and electrical integrity.