Abstract: A while-drilling tool comprising a motor, a transmission coupled to the motor, and a pump comprising a first piston disposed in a first chamber and a second piston disposed in a second chamber and coupled to the first piston. A planetary roller-screw is coupled between the pump and the transmission. A valve block is configured to fluidly communicate with the first and second pump chambers, a borehole in which the while-drilling tool is configured to be positioned, and a formation penetrated by the borehole.

Abstract: An apparatus comprising a fluid communication device configured to extend from a drill string and establish fluid communication with a subterranean formation penetrated by a wellbore in which the drill string is positioned, wherein the drill string comprises a passage configured to conduct drilling mud and an opening extending through an outer surface thereof and into a cavity. A sample chamber is coupled within the cavity and is in selectable fluid communication with the formation via the fluid communication device.

Abstract: An apparatus comprising a fluid communication device configured to extend from a drill string and establish fluid communication with a subterranean formation penetrated by a wellbore in which the drill string is positioned, wherein the drill string comprises a passage configured to conduct drilling mud and an opening extending through an outer surface thereof and into a cavity. A sample chamber is coupled within the cavity and is in selectable fluid communication with the formation via the fluid communication device. A retainer is configured to absorb axial loading of the sample chamber within the cavity.

Abstract: A downhole formation fluid pumping and a sampling apparatus are disclosed that may form part of a formation evaluation while drilling tool or part of a tool pipe string. The operation of the pump is optimized based upon parameters generated from formation pressure test data as well as tool system data thereby ensuring optimum performance of the pump at higher speeds and with greater dependability. New pump designs for fluid sampling apparatuses for use in MWD systems are also disclosed.

Abstract: A sample module for a sampling while drilling tool includes a sample fluid flowline operatively connectable between a sample chamber and an inlet, for passing a downhole fluid. A primary piston divides the sample chamber into a sample volume and a buffer volume and includes a first face in fluid communication with the sample volume and a second face in fluid communication with the buffer volume. An agitator is disposed in the sample volume for agitating the sample fluid. A secondary piston includes a first face in fluid communication with the buffer volume having buffer fluid disposed therein and a second face.

Abstract: A downhole formation fluid pumping and a sampling apparatus are disclosed that may form part of a formation evaluation while drilling tool or part of a tool pipe string. The operation of the pump is optimized based upon parameters generated from formation pressure test data as well as tool system data thereby ensuring optimum performance of the pump at higher speeds and with greater dependability. New pump designs for fluid sampling apparatuses for use in MWD systems are also disclosed.

Abstract: A sampling while drilling tool positionable in a wellbore penetrating a subterranean formation is provided. The tool includes a drill collar, at least one sample chamber, at least one flowline and at least one cover. The drill collar is operatively connectable to a drill string of the sampling while drilling tool. The drill collar has at least one opening extending through an outer surface thereof and into a cavity. The drill collar has a passage therein for conducting mud therethrough. The sample chamber is positionable in the cavity of the drill collar. The flowline in the drill collar, the at least one flowline operatively connectable to the sample chamber for passing a downhole fluid thereto. The cover is positionable about the at least one opening of the drill collar whereby the sample chamber is removably secured therein.