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.

Date of Patent:
Sep. 19, 2017

Filed:

Aug. 06, 2015
Applicant:

Schlumberger Technology Corporation, Sugar Land, TX (US);

Inventors:

John Rasmus, Richmond, TX (US);

William Lesso, Anderson, TX (US);

John James, Houston, TX (US);

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B 7/00 (2006.01); E21B 47/06 (2012.01); E21B 49/00 (2006.01); E21B 47/10 (2012.01); G01V 9/00 (2006.01); G06F 15/00 (2006.01); E21B 21/08 (2006.01);
U.S. Cl.
CPC ...
E21B 21/08 (2013.01); E21B 7/00 (2013.01); E21B 47/06 (2013.01); E21B 47/10 (2013.01); E21B 49/005 (2013.01); G01V 9/00 (2013.01); G06F 15/00 (2013.01);
Abstract

A method for estimating equivalent top of fluid level or a theoretical surface annular back pressure in a subterranean wellbore includes acquiring first and second axially spaced pressure measurements in the wellbore. The pressure measurements may then be processed to compute the equivalent top of fluid level and/or theoretical surface annular back pressure of drilling fluid between the measurement locations. A tool string including a large number of axially spaced pressure sensors (e.g., four or more or even six or more) electronically coupled with a surface processor via wired drill pipe may be used to obtain a plurality of values corresponding to various wellbore intervals. The equivalent top of fluid level and/or theoretical surface annular back pressures may be used in automated managed pressure drilling operations.


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