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:
Nov. 22, 2011
Filed:
Dec. 21, 2007
Tong Zhou, Quincy, MA (US);
Felix Chen, Newtown, CT (US);
Charles R. Case, West Redding, CT (US);
Darwin V. Ellis, Ridgefield, CT (US);
Bradley Albert Roscoe, Ridgefield, CT (US);
Tong Zhou, Quincy, MA (US);
Felix Chen, Newtown, CT (US);
Charles R. Case, West Redding, CT (US);
Darwin V. Ellis, Ridgefield, CT (US);
Bradley Albert Roscoe, Ridgefield, CT (US);
Schlumberger Technology Corporation, Cambridge, MA (US);
Abstract
A more precise determination of bulk formation density is attainable using a pulsed γ-γ density tool and simultaneously compensating for interactions due to photoelectric effect and density variations caused by standoff. A source directs energetic particles at a formation having a known photoelectric factor and electron density. One or more photons either emitted or deflected from the formation are captured at a first or second detector, respectively spaced at first and second distances from the source, and separated from each other by a third distance. First and second total energies of the photons respectively striking the first and second detectors are measured during a time interval. A first filter is disposed between the first detector and formation effective to cause Pe response to match standoff influence, thereby compensating for both effects simultaneously. In some embodiments, a second filter is provided between the second detector and formation.