摘要 |
The present invention provides a tool and method for obtaining at least one parameter of interest such as pressure of a subterranean formation in-situ. The tool comprises a carrier member for conveying the tool into a borehole, at least one selectively extendable member mounted on the carrier member for separating the annulus into a first portion and a second portion, a first port exposable to formation fluid in the first portion, a second port exposable to a fluid containing drilling fluid in the second portion, a first sensor for determining a first value indicative of a first portion characteristic, a second sensor for determining a second value indicative of a second portion characteristic referenced to the first value. The method comprises conveying a tool into a borehole, separating the annulus into a first portion and a second portion by extending at least one selectively extendable member, exposing a first port to formation fluid in the first portion, exposing a second port to fluid in the second portion, determining a first value indicative of an absolute pressure in the first portion, determining a second value indicative of a differential pressure of the second portion referenced to the absolute pressure of the first portion, and combining the first and second values using a processor, the combination being indicative of formation pressure. |