[54] INSTRUMENT CHASSIS AND BODY
SUPPORTS FOR PIPELINE SURVEY PIG
[75] Inventors: Steven G. Petermann, Piano; Michel L. Cabiran, Allen; John D. Cooper,
Garland, all of Tex.
[73] Assignee: Atlantic Richfield Company, Los Angeles, Calif.
[21] Appl. No.: 67,511
[22] Filed: Jun. 26, 1987
[51] Int. CI.* E21B 47/022; G01C 9/06
[52] U.S. a 33/313; 33/178 F;
33/307; 33/304; 73/865.8; 73/866.5; 324/220
[58] Field of Search 33/302, 304, 306, 307,
33/312, 313, 178 F, 542, 544; 73/865.8, 866.5, 151, 154; 324/220, 221
[56] References Cited
U.S. PATENT DOCUMENTS
1,921,522 8/1933 Hamer 33/178 F
2,746,162 5/1956 Picard 33/312
4,098,126 7/1978 Howard 33/178 F
4,285,242 8/1981 Braithwaite 324/220
4,372,658 2/1983 O'Connor et al 324/220
4,468,863 9/1984 Van Steenwyk 33/304
4,524,324 6/1985 Dickinson 33/304
4,717,875 1/1988 Lara 33/313
4,747,317 5/1988 Lara 73/865.8
Primary Examiner—William A. Cuchlinski, Jr.
Assistant Examiner—Patrick R. Scanlon
Attorney, Agent, or Firm—Michael E. Martin
[57] ABSTRACT
A pipeline survey pig includes an elongated hollow pig body having an enclosure for supporting a generally cylindrical tubular instrument chassis which, in turn, supports an inertial reference unit and associated signal processing and recording devices. A plurality of resilient cup members support the pig body for traversal through a pipeline section under the urging of pressure fluid. The cup members are spaced apart and secured to the pig body by spacer members which may be selectively provided to predetermine the axial spacing of the cup members so that the center of stiffness of the pig is in a predetermined position. The instrument chassis is secured in the pig body by a cam mechanism which is actuatable from one end of the chassis after insertion into the pig body to wedge opposed chassis door members into engagement with the pig body to enhance heat transfer between the chassis and the pig body.
9 Claims, 5 Drawing Sheets
