Abstract: For use in a formation testing tool adapted to be lowered into a borehole on a logging cable, apparatus is set forth which conducts formation measurements including extension of a snorkel into a formation of interest, initiating a drawdown beginning at a first time and terminating at a second time. The flow rate in the drawdown is measured. The present apparatus and method further determine a Horner Plot for that particular formation, and measure the slope of the Horner Plot and also extend the Horner Plot to thereby obtain the intercept representative of final formation pressure after build-up. A relationship is evaluated, and computer circuitry for determining permeability responds to the slope of the Horner Plot, formation fluid viscosity, pretest flow rate and formation thickness to yield permeability.

Abstract: A formation tester is set forth. The device utilizes a snorkel extending from the formation tester to obtain a pressure test and collect samples from a formation of interest. The apparatus includes multiple sample storage containers. The sample line is connected to storage containers and also to pretest and post-test drawdown elements which alter the sample line back pressure, thereby cooperating with an equalizing valve to selectively isolate the snorkel from fluid and fluid pressures in the well.

Abstract: In a formation testing apparatus lowered into a well to conduct various tests, an internal hydraulic powered system operates various components. In the present disclosure, an improved valve having metal seats overlayed with an elastomeric material cooperates with valve elements to thereby enhance low power for valve operations. The valve element and mating valve seat cooperate on valve opening or closing to reduce valve power requirements and the forces needed for operation.

Abstract: In a formation tester having a snorkel extending laterally for penetration of a formation, differential sticking may occur. In the preferred embodiment, the snorkel is surrounded by a seal ring and a resilient pad around the snorkel. The present invention includes upper and lower, evenly spaced push-off pistons. They are extendable parallel to the snorkel to push the tool body away from the wall of the borehole. The pistons extend piston rods supporting end located pads to enable breaking of differential sticking on retraction of the snorkel.