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:
Aug. 10, 1993
Filed:
Apr. 22, 1991
Robert Desbrandes, Baton Rouge, LA (US);
Gulf Research Institute, Chicago, IL (US);
Abstract
Test apparatus, and method for accurately and quickly measuring formation pressure, and permeability in oil and gas producing formations; especially low or high permeability formations. The test apparatus can be transported on a drill string, or cable. Preferably, it is employed as a component of a wireline test apparatus. The test apparatus includes, as part and parcel of the combination, an extended drawdown subassembly, or formation pressure test unit, directly associated with the tool flowline. By applying a very slow rate of pressure decrease in the tool flowline, the formation pressure and permeability can be quickly determined, generally during the first minute of testing. In high permeability and soft formations, the formation pressure is determined even if the seal is lost during the flowing period. In low permeability formations, corrections can be made for the supercharging effect using the data collected. A simple mathematical model can be used for determining formation pressure, formation permeability, supercharging, and mudcake characteristics from the data obtained.