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:
Feb. 23, 2010
Filed:
Jul. 03, 2007
Terizhandur S. Ramakrishan, Boxborough, MA (US);
John Tombari, Spring, TX (US);
Terizhandur S. Ramakrishan, Boxborough, MA (US);
John Tombari, Spring, TX (US);
Schlumberger Technology Corporation, Cambridge, MA (US);
Abstract
A cased hole pressure test tool is used to determine the integrity of cement between two points in a borehole in terms of permeability or transmissibility. The test tool drills at least one probe hole through the casing up to the cement. In one embodiment, two probes are set and the dissipation of a pressure pulse through the cement initiated by the first probe is observed by the second probe. In another embodiment, one probe hole is in hydraulic communication with the borehole fluid and a single offset probe is set in another probe hole. Fluid (water) is then added to the borehole to cause a pressure increase in the borehole fluid. Detection of the pressure increase through the cement by the offset probe is indicative of a loss of hydraulic isolation. Packers may be used to isolate the portion of the borehole under test. A mechanism for generating a pressure pulse of known magnitude is also described.