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:
Oct. 18, 1994
Filed:
Nov. 22, 1991
Terence P O'Sullivan, East Kalimantan, ID;
William C Allen, Pasadena, CA (US);
Union Oil Company of California, Los Angeles, CA (US);
Abstract
A differential analysis method can be used to determine the presence or absence of a fluid in contact with a tubing string within a wellbore. The method uses a signal generator and detects tubing-perturbed signals, searches for an initial interfacial indicator within a window, axially aligns indicators within a data series as the detector traverses the tubing, discerns an adjacent interfacial indicator known to be incrementally changed by the presence of the fluid, and compares the adjacent indicators to the known incremental change. Even if the absolute location or condition of the interface is uncertain, the relative change indicates the presence or absence of fluid. A prior condition indicator can also be used to determine a second window for detecting an adjacent surface signal indicators. The arbitrary or prior condition baseline avoids the need to 'know' the actual properties of intervening materials currently required for analysis of casing conditions and some of the extrapolation limitations inherent in current analysis methods. The method can also achieve accurate results by iterating on the initial indicator.