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:
Jun. 22, 2010
Filed:
Dec. 28, 2007
John Edwards, Mediant Al Alam, OM;
Hemant K. J. Ladva, Missouri City, TX (US);
John Edwards, Mediant Al Alam, OM;
Hemant K. J. Ladva, Missouri City, TX (US);
Schlumberger Technology Corporation, Sugar Land, TX (US);
Abstract
The use of time-lapsed NMR diffusivity measurements in an observation well is disclosed. The observation well is cased in the zone of interest with non-magnetic and non-conductive casing that is invisible to the NMR tool. Second, because NMR measurements have a dead zone in front of the antenna depending on the spatial variation of the fixed magnet strength, for example about 2.7 inches, a distance between the casing and the formation is reduced to less than the dead zone length by drilling the observation well at small deviation of about 5° and running the casing without centralizers. Both the casing and the pad-type NMR tool will follow the low side of the borehole, ensuring the measurement volume of the NMR tool is inside the formation and beyond the annulus. With the appropriate observation well completion, time-lapse diffusivity measurements with pad-type NMR tools can address several shortcomings in the current practice of monitoring EOR processes that rely upon changes in density and hydrogen index (HI). Various uses of NMR imaging in wells cased with non-metallic casing are also disclosed.