Abstract: A differential pressure actuating system for downhole tools provides endless operation by the use of the differential pressure between two isolated zones of a well as a power source for the tool. That differential pressure is applied across a power transfer element to operate the downhole tool.

Abstract: An electric coupling for two electric circuits in a well includes an electric contact and a contact receiver connected to respective ones of the circuits so that a contact/receiver pair is formed when the contact and receiver are moved together The receiver is sealed by a sealing member. The sealing member is disposed so that it is penetrated by the contact when the contact and receiver are moved together. A coupling including two such pairs is preferably used to connect two electric wires in the well to form a current conductive loop linking two electric coils. One of the coils is adapted to be moved in the well relative to the other coil which is adapted to be fixed in the well. In a preferred embodiment, one coil is on a wireline tool and the other coil is on a downhole tool.

Abstract: A downhole formation test pump includes a progressive cavity pump having a helical rotor received in a helical cavity of a stator. The pump may be disengaged by withdrawing the rotor from the stator to provide a bypass position so that the downhole formation being tested can be allowed to flow freely if it is capable.

Abstract: A bypass valve for bypassing well fluids, and method of use thereof. The valve comprises a tubular housing defining a bypass port therethrough with an inner sleeve mandrel defining a bypass port initially aligned with the bypass port in the housing. The valve also comprises a power mandrel slidably disposed within the housing such that, as weight is set down on the power mandrel, pressure is increased in a first oil chamber which has a rupture disc in communiction therewith. When the pressure reaches a predetermined level, the rupture disc ruptures so that the oil chamber is emptied into the well annulus. This allows the power mandrel to move and strike an operating mandrel which is also slidably disposed in the housing. The jarring force shears a shear pin which allows the operating mandrel to move a floating piston disposed in a second oil chamber. A metering cartridge restricts flow of fluid out of the second metering chamber, thereby providing a time delay for movement of the operating mandrel.

Abstract: Well tools are provided which although pressure responsive, may be maintained by a hydraulic lockout in a nonresponsive condition until a threshold actuation step is performed. This lockout may be achieved by a hydraulic mechanism which allows pressure to be stored in a fluid spring during periods of increased pressure at the pressure source, and which traps these pressures even when pressure at the pressure source is reduced. When the tool is desired to be responsive to pressure cycles, a valve may be opened communicating the pressure in the fluid spring to a movable member in the well tool. This differential may be established by a differential between the pressure in the fluid spring and the pressure source. Communication of pressure in the fluid spring to a movable mandrel will then allow operation of the well tool in response to pressure cycles at the pressure source in accordance with the established design of the well tool.

Abstract: An annulus pressure responsive well tool includes a selectively actuatable hydraulic bypass for bypassing a pressure differential across a power piston of the tool so that an operating element associated with the power piston will remain in a chosen position during a subsequent change in well annulus pressure.

Abstract: A downhole electrical power supply apparatus has a high fluid pressure source zone and a low fluid pressure discharge zone each defined at least partially within the apparatus. A fluid powered engine provides rotational mechanical output and is powered by fluid flowing from the source zone through the engine to the discharge zone. An electrical powered generator converts the rotational mechanical output of the engine into electrical output.

Abstract: A differential pressure actuating system for downhole tools provides endless operation by the use of the differential pressure between two isolated zones of a well as a power source for the tool. That differential pressure is applied across a power transfer element to operate the downhole tool.

Abstract: A well fluid sampling apparatus provides a time delay after actuation of the tool and before a sample is taken. The tool is operated by well pressure acting on a piston. The piston is initially hydraulically blocked so that it cannot move. The time delay is provided after the piston begins moving. Additional time delay devices can optionally be included.

Abstract: A well surging system having pressure actuated ball valves and a mechanical actuating backup for the upper of said ball valves. The apparatus comprises a valve assembly portion containing the upper and lower ball valves which may be independently pressure actuated. The valve assembly portion also includes an extension portion having an extension mandrel therein connected to an upper ball valve actuator. The lower ball valve is opened by increasing the pressure in the well annulus around the valve assembly portion with respect to a flow bore therethrough. The upper ball valve is similarly pressure actuated. In the event that the upper ball valve pressure actuation is fully or partially unsuccessful, a probe assembly portion may be lowered on a wireline into the extension portion adjacent to the valve assembly portion. The probe assembly portion is adapted for releasable engagement with a lug extending inwardly from the extension mandrel.

Abstract: An annulus pressure responsive downhole tool includes a housing having a power piston slidably disposed therein. First and second pressure conducting passages communicate a well annulus exterior of the housing with first and second sides of the power piston. A metering cartridge is disposed in the second pressure conducting passage for delaying communication of relatively rapid changes in well annulus pressure to a second side of the power piston to thereby operate the power piston, and for communicating relatively slow changes in well annulus pressure to the second side of the power piston so that hydrostatic well annulus pressure is substantially balanced across the power piston as the apparatus is run into a well. A gas energized compressible liquid spring is contained in a first portion of the second pressure conducting passage between the second side of the power piston and the metering cartridge.

Abstract: A downhole tool such as a tester valve originally constructed to operate with a compressible gas spring may be modified to operate with a compressible liquid spring. The volume of a spring chamber is increased. A differential area of a power piston is decreased. A flow restriction in a metering cartridge associated with the spring chamber is increased. Also, a relief valve is provided to allow fluid to be relieved from the tool into the well annulus upon expansion of the compressible liquid due to heating as the tool is lowered into a well if the expansion of liquid exceeds the available volume in the tool.

Abstract: An annulus pressure responsive tester valve has a housing with a flow passage disposed therethrough. A full opening ball valve is disposed in the housing. A differential pressure responsive power piston is slidably disposed in the housing and operatively connected to the ball valve. A resilient spring retaining assembly is operatively associated with the power piston ad the housing for releasably retaining the power piston in a position corresponding to an open position of the ball valve until a force urging the power piston toward a position corresponding to a closed position of the ball valve exceeds a retaining force provided by the resilient spring retaining assembly. This, combined with an appropriate selection of flow restrictors in a metering cartridge associated with a compressed nitrogen chamber located below the power piston, allows the tester valve to have its ball valve left in an open position by bleeding off well annulus pressure at a sufficiently low rate.

Abstract: An annulus pressure responsive tester valve which includes a pressure-assisted isolation valve including a pressure differential metering cartridge utilizes a sleeve-type valve section having a ported sleeve mandrel and a ported outer valve sleeve member and also having a choke associated therewith for controlling the flow of fluids through the sleeve-type valve.