Abstract: Gas-liquid mixtures, such as produced from crude oil reservoirs, are separated in a separator system having a separator vessel with a spiral inlet duct for centrifuging the gas-liquid mixture and an active centrifuge for removing entrained gas after primary separation by the spiral inlet duct. Active centrifuging is carried out by a rotating member disposed in a second compartment in the separator vessel having a plurality of circumferentially-spaced, radially-extending chambers for imposing centrifugal force on a quantity of liquid in each chamber. The chambers may discharge liquid through a porous outer cylindrical wall or through axially disposed discharge ports. The plural chambers minimize remixing of gas and liquid during centrifuging. The centrifuge may be an external rotary-tube type centrifuge with plural separator chambers.

Abstract: Seismic signals are generated in an earth formation at a selected point in a wellbore by apparatus insertable in the wellbore at the distal end of a tubing string. The apparatus is adapted to receive hydraulic pressure fluid from the tubing string for deploying contactor pads in engagement with the wellbore wall and for transmitting seismic signals through the pads to the earth formation. In one embodiment a hydraulic piston is directly connected to linkage for the contactor pads and an oscillatory signal is imposed on the piston for generating vibratory seismic signals. In a second embodiment, a compressed gas-driven impactor is moved to and held in a cocked position by a hydraulically-actuated setting and latching mechanism. Hydraulic control valves and electrical operating circuits are disposed on the apparatus and may be controlled from the surface by way of a wireline cable extending through the tubing string.

Abstract: A weld detection system for a pipeline survey pig includes a plurality of weld sensor units mounted spaced apart circumferentially on fore and aft pig support members and arranged in close proximity to the pipe wall. The sensor units comprise permanent magnet members for generating a magnetic flux field around a wire coil which is modified upon passing a girth weld or other magnetic anomaly in the pipe to produce a voltage signal which is conditioned by an amplifier and filter circuit to a signal suitable for input to a digital activation circuit. The digital activation circuit receives conditioned signals from opposed pairs of sensor units on the support members to distinguish transverse girth welds from spiral or longitudinal welds. The digital activation circuit includes circuit elements for timing the sensor output signals of the fore and aft detector arrays for measuring the velocity of the survey pig through the pipe.

Abstract: A seismic array system for receiving seismic signals at spaced-apart points in a wellbore is deployable on coiled tubing from the surface through an isolator apparatus mounted on the wellhead. The array includes spaced-apart geophone sondes which have hydraulic actuators for extension of sonde support pads into engagement with the wellbore wall. Each sonde has a hydraulic control unit for controlling operation of the hydraulic actuator to extend or retract the pads and for preliminary processing of signals received through the geophones of each sonde. Hydraulic fluid and electrical control signals are communicated through the coiled tubing from the surface. A signal processing unit is deployed at the upper end of the array string for final or intermediate processing of the geophoen signals from each sonde.

Abstract: A displacement amplifier interconnects a piezoelectric actuator with a displacement member and comprises respective bellows members of differential diameter defining first and second expansible chambers which are liquid filled and respond to linear displacement of a stack of piezoelectric disks to provide an amplified linear displacement to the displacement member. The transducer is particularly useful as a signal transmitting or receiving transducer for acoustic wave generation or measurement for wellbore logging tools.

Abstract: A traveling seal system for blocking a predetermined section of fluid transmission pipeline for repair or modification or for pressure testing the pipeline includes two seal devices which are interconnected by a flexible cable and are supported for traversal through a pipeline by spaced apart resilient support members supporting respective body members. Each of the seal devices includes radially extensible brake pads which are actuated by annular pistons slidable on the body of the seal devices, respectively, and are disposed in annular pressure chambers formed by the body. Each of the seal devices includes an onboard hydraulic pump for actuating the brake pads between extended and retracted positions and at least one of the seal devices includes an onboard pump for pumping pressure fluid into the space between the seal devices.

Abstract: An acoustic wellbore logging tool transducer formed of a composite plate member having at least one plate of a magnetostrictive material which responds to a magnetic field to elongate or contract to effect displacement of said plate member within a cavity formed in a housing section of the logging tool. The logging tool cavity may be exposed to wellbore fluid in direct contact with the plate member whereby acoustic pressure pulses may be delivered directly to the wellbore fluid by the transducer element. Spaced apart electromagnets are disposed in the housing section on opposite sides of the cavity for effecting controlled displacement of the plate member to generate acoustic waves in a liquid-filled wellbore.

Abstract: An ultrasonic logging tool (borehole televiewer) which utilizes a rotating transducer which is exposed directly to the fluids in the borehole during logging operations.

Abstract: A pipeline survey pig includes an elongated hollow pig body having an enclosure for supporting a generally cylindrical tubular instrument chassis which, in turn, supports an inertial reference unit and associated signal processing and recording devices. A plurality of resilient cup members support the pig body for traversal through a pipeline section under the urging of pressure fluid. The cup members are spaced apart and secured to the pig body by spacer members which may be selectively provided to predetermine the axial spacing of the cup members so that the center of stiffness of the pig is in a predetermined position. The instrument chassis is secured in the pig body by a cam mechanism which is actuatable from one end of the chassis after insertion into the pig body to wedge opposed chassis door members into engagement with the pig body to enhance heat transfer between the chassis and the pig body.

Abstract: A borehole centralizer includes an elongated shank member on which opposed head members are slidable and are connected to articulated arms which are movable radially inwardly and outwardly to centralize a tubing string or apparatus in a borehole in which the centralizer is disposed. A tension coil spring is disposed around the shank and connected to the opposed head members for exerting an axially directed force which is converted to radially directed forces urging the articulated arms radially outwardly. The centralizer is operable to exert substantially constant outward biasing forces on the articulated arms for a relatively wide range of borehole diameters.

Abstract: A well tool having a locking arm that is rapidly deployed by a long strike of a hydraulic piston having a small area and is locked in the deployed position by a short stroke of a hydraulic piston having a larger area.

Abstract: A wellbore fluid sampling apparatus includes an elongated tubular housing having a floating piston disposed therein and dividing a bore in the housing into first and second chambers, one of the chambers being in communication with ports in the sidewall of the housing for receiving a sample of wellbore fluid in response to movement of the piston to enlarge the one chamber. The other chamber is charged with a liquid to prevent displacement of the piston until a control valve in the housing allows charging fluid to escape into a reservoir chamber whereby the piston moves to receive the fluid sample under wellbore pressure. The floating piston actuates a rod connected to a closure member to close off the bore in the fluid sampling chamber when a suitable fluid sample is obtained. A detent locks the actuating rod and the closure member in the closed position to capture the fluid sample for retrieval and analysis.

Abstract: A connector for attaching a downhole tool to the end of a tubing string insertable in a wellbore includes a frangible coupling portion having a pin with a predetermined cross sectional area which will fail in tension to separate the connector from the tool if the tool becomes stuck in the wellbore. The pin is disposed in a body member of the connector and interconnected therewith by spring washers to absorb transient shock or impact loads on the tool. The connector includes passages for extending electrical conductors through the coupling portion whereby electrical signals may be transmitted through the tubing string to the downhole tool.

Abstract: A downhole tool is supported by coilable tubing extending into the wellbore from a tubing injection and withdrawal apparatus and includes an elongated electrical signal transmitting cable extending through the tube between the tool and the injection apparatus. The tool is connected to one end of the tube by a connector assembly which provides for limited swiveling movement of the tool relative to the end of the tube to preclude excessive lateral loads from being exerted on the tool during positioning of the tool in the wellbore. The connector assembly includes a frangible coupling comprising coupling members which are interconnected by shearable pins whereby separation from the tool will occur at the connector assembly in the event the tool becomes stuck in the wellbore. One of the coupling members includes a fishing neck for engagement with a suitable fishing tool whereby the downhole tool may be retrieved if separated from the tubing.