Abstract: The apparatus includes a pump for circulating pressurized fluid in a wellbore. A control device controls the pump which a conduit interconnects to the wellbore. A downhole transducer detects changes in fluid pressure at a downhole location and generates signals accordingly. A processor generates actuator commands based on the signals. Actuators activate a downhole tool based on the actuator command. A modulating valve modulates the fluid pressure. A remote transducer detects the pressure remotely from the downhole transducer. The control device causes the pump to generate acoustic signals in the fluid via wave forms which the downhole transducer detects. The modulating valve generates wave forms in the fluid. The control device sends control signals via the fluid to the downhole transducer. Consequently the processor actuates the tools. Following correct actuation the modulating valve generates signals via pressure changes which the remote transducer receives to indicate successful tool deployment.

Abstract: A drillpipe sub (30) comprises a shaft (32), a first frustoconical member (34) encircling, and fixedly mounted on, the shaft (32), and a second, opposed frustoconical member (36) encircling, and slidably mounted on, the shaft (32). The first frustoconical member (34) is bonded at its base (38) to the base (40) of the second frustoconical member (36).

Abstract: An apparatus and method for deploying a so-called compact battery/memory logging tool, for acquiring data in deviated or horizontal wells in the oil and gas well data logging industry. A drillpipe assembly (10) includes a drillpipe (11) having secured at a downhole end thereof a delatching latching sub (12) containing an extendable running sub (13) supporting a battery/memory logging tool (14). The running sub (13) occupies an initial, retracted position during deployment of the drillpipe (11), whereby the logging tool (14) is protected within one or more drillpipe stands. The running sub is movable by a messenger (26) to a second, extended position in which its logging tool (14) protruding from the drillpipe (11). The drillpipe assembly may therefore be used to protect the logging tool (14) during running in operations; and then to extend the logging tool permit commencement of logging operations.

Abstract: In the field of tools for use in boreholes, an apparatus (10) includes a pump (11) for circulating fluid under pressure in a wellbore (12).

Abstract: A method of well logging in which the logging tool is delivered to the bottom of the well within a drill pipe and then the well is logged by withdrawing the drill pipe with the sensor portion of the logging tool protruding from the drill pipe. Following the logging operation, the logging tool is returned to the surface by reverse circulation.

Abstract: A self contained logging tool comprising electronic apparatus for logging a well is disclosed. This tool includes a normally open fluid flow valve structure being activated to operation by differential movement of drill pipe in which the logging tool resides. The valve structure operates to gradually close and thereby restrict the flow of fluid through the valve, which in turn restricts the flow of fluid within the drill pipe. This flow restriction results in increasing the back pressure within drill pipe to provide an indication at the surface that the logging tool is struck.

Abstract: A drillpipe sub (30) comprises a shaft (32), a first frustoconical member (34) encircling, and fixedly mounted on, the shaft (32), and a second, opposed frustoconical member (36) encircling, and slidably mounted on, the shaft (32). The first frustoconical member (34) is bonded at its base (38) to the base (40) of the second frustoconical member (36).

Abstract: A well logging method and apparatus is described, which enables well logging to be conducted while still allowing passage of fluid mud within the well to maintain well control.

Abstract: A method of well logging in which the logging tool is delivered to the bottom of the well within a drill pipe and then the well is logged by withdrawing the drill pipe with the sensor portion of the logging tool protruding from the drill pipe. Following the logging operation the logging tool is returned to the surface by reverse circulation.

Abstract: In the oil and gas well data logging industry there is a need for an improved apparatus and method for deploying a so-called compact battery/memory logging tool, for acquiring data in deviated or horizontal wells.

Abstract: A method of well logging in which the logging tool is delivered to the bottom of the well within a drill pipe and then the well is logged by withdrawing the drill pipe with the sensor portion of the logging tool protruding from the drill pipe. Following the logging operation, the logging tool is returned to the surface by reverse circulation.

Abstract: The well logging tool comprises differential valve means allowing passage of fluid through said tool during logging operations on when the tool becomes jammed inside a drillpipe.

Abstract: The pumping sub comprises first and second inflatable bladders which are pressurized to inflate to accommodate various pipe diameters. Pressure relief value means is provided to assist in clearing obstructions within the pipe. The pumping sub acts as a parachute to slow the fall of a logging tool and enables the logging tool to be pumped up and down a drill pipe. FIG.