The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 05, 1988
Filed:
Feb. 19, 1986
Pedro F Lara, Dallas, TX (US);
Atlantic Richfield Company, Los Angeles, CA (US);
Abstract
A change in curvature or displacement of a section of submarine or subterranean fluid transmission pipeline is measured by traversing the pipeline with a pig having an onboard instrument package, including accelerometers and a longitudinal position measuring device comprising a magnetometer for counting the girth welds or other known magnetic anomalies along the section of pipeline to be measured. The accelerometers are mounted at the central longitudinal axis of the pig which is substantially coincident with the central longitudinal axis of the section of pipeline being measured so that the roll attitude of the pig does not influence the signals generated by the accelerometers. This arrangement precludes the requirement of mounting the accelerometers on a gyroscopic stabilized platform since the absolute position of the pig in space is not required, but primarily the change in curvature or displacement of the pipeline from a predetermined course is what is desired to be known. The pig weight is minimized and supporting structure is sufficiently stiff as to provide natural modes of vibration at frequencies higher than the frequencies of signals of interest as the pig traverses the pipe.