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:
Apr. 30, 1991
Filed:
Aug. 25, 1989
Allen Duckworth, Middlefield, CT (US);
Derek Barnes, Wallingford, CT (US);
Thomas L Gennings, Anchorage, AK (US);
Teleco Oilfield Services Inc., Meriden, CT (US);
Abstract
Downhole measurements are made for accurately determining whether or not a core barrel contains an appropriate amount of core sample before retrieval of the coring tool is attempted. This is accomplished by using a known apparatus for measuring downhole weight on bit (WOB) at the beginning of a coring run to make a first measurement corresponding to the weight of all drillstring components suspended below the measurement point at a selected depth. Thereafter, the coring tool drills down the length of the core barrel. When sufficient drilling takes place to obtain a core, the drillstring is pulled up to the same depth as the measurement and a second measurement is taken. After correcting the data for temperature changes, the difference in between the first and second measurements is obtained and compared to a calculated weight for a full core. If the difference in measurements is less than the calculated full core weight, then it is known that a full core has not been obtained and the coring operation is continued. However, if the difference in the measurements does correspond to the calculated weight of a full core barrel, then the drillstring is retrieved and the acquired core sample is obtained.