Gearhart Tesel Limited

Computalog USA Inc.

Frank B Bardsley

David E Stoddart

Michael Yuratich

Alec B Sycha

Timothy G Boxell

In an apparatus and method for actuating arms used on a borehole data-logging tool to deploy measuring instruments against a borehole wall, a mandrel is provided. At least one arm carried by the mandrel is mounted to the mandrel to move between an expanded position, in which a part of the arm projects from the mandrel, and a retracted position. A resilient biassing compression spring provides a resilient biassing force on each arm for biassing the arm towards its expanded position. A hydraulic piston and cylinder assembly associated with each arm restrains the arm against movement towards its expanded position. A drive piston and cylinder assembly acts upon the resilient biassing compression springs for adjusting the resilient biassing force acting upon each arm.

Apparatus and method for actuating arms

A tool for use downhole has an elongate body, arms movably mounted on the body and means for controlling movement of the arms between an operational position and a retracted position. Movement of the arms is controlled by a motor and a transmission, according to one aspect of the invention the arms being suspended independently of one another and in a second aspect of the invention, movement of the arms being controllable remotely from the tool.

Downhole tools

A connector is provided for making electrical connection between electrical conductors in a first connector casing and electrical conductors in a second connector casing. The first and second connector casings are mutually engageale in one orientation only by relative axial movement. The connector has a first connector assembly (10) at one end thereof and a second connector assembly at the other end thereof, the connector assemblies being engageable with corresponding connector assemblies in other tool bodies. The connector assemblies each have a connector body (11) and a support ring (15) and pins (22, 23, 25) for preventing relative axial and rotational movement between the ring (15) and the connector casing (20), the pins (22, 23 and 25) making no direct engagement with the connector assemblies.

Connector apparatus

A tool for use downhole has means (18, 19, 20, 44) for engaging materials surrounding the hole. The engagement means (18, 19, 20, 44) are operated by hydraulic pressure controlled by a hydraulic circuit (10). A hydraulic power module (11) is provided for varying hydraulic pressure in the hydraulic circuit (10) to effect movement of the engagement means (18, 19, 20, 44). In case of failure, a dumping assembly (17) is provided to allow relief of hydraulic pressure in the circuit (10). The dumping assembly (17) includes a dump chamber (62) of variable volume, a dump valve (60) and a non-return valve (61); the hydraulic circuit being capable of being re-set downhole after dumping, there being no need to bring the tool to the surface.

Growing community of inventors

Andover, United Kingdom

Frank B Bardsley