Patent ID: 6871713
Filing Date: 2005-03-29
Classification: E21B

Abstract:
1. A downhole formation test tool, comprising; a. a carrier member for conveying the formation test tool into a borehole; b. a retractably extendable pad for sealingly engaging a borehole wall adjacent a fluid bearing formation, the pad having a port therein for receiving fluid from said formation; c. a fluid transfer device operatively associated with the retractably extendable pad for selectively adjusting a fluid pressure; d. a sensor for detecting the fluid pressure proximate said port; and e. a downhole controller operatively coupled to the sensor and the fluid transfer device, said downhole controller acting according to programmed instructions to control said fluid transfer device in response to signals from said sensor thereby adjusting the fluid pressure at the port as the retractably extendable pad is extended and retracted.