Tractor Unit for a Wireline Logging Tool String
AssigneePetromac IP Limited
InventorStephen Peter McCormick
Life of this patent
Estimating the term…
Abstract
The disclosure relates to a carriage apparatus for carrying a tool string down a wellbore in a wireline logging, and an orientation apparatus and hole finder device for a wireline logging tool string. In some embodiments the carriage includes a protection structure which extends longitudinally around a wheel of the apparatus to thereby prevent a side of the wheel from contacting a wall of the wellbore. In some embodiments an orientation apparatus and hole finder are arranged so that the orientation apparatus orientates the hole finder device in the wellbore so that a tip of a nose section of the hole finder is elevated above a low side of the wellbore by a height and offset from and above a longitudinal axis of the tool string.
Claims18
A tractor unit for conveying an elongate sensor assembly through a wellbore, the tractor unit comprising:
- a main body comprising at least one engagement structure to connect the tractor unit to the sensor assembly, and
- one or more main wheels arranged to rotate about an axis of rotation substantially perpendicular to a longitudinal axis of the sensor assembly when the tractor unit is connected to the sensor assembly, and
- an orientation structure defining a form having a transverse outline which has a rotational centre, wherein the rotational centre is offset from a centre of mass of the elongate sensor assembly so that, in use, the tractor unit is oriented in a most stable position with the centre of mass of the elongate sensor assembly below the rotational centre.
A logging tool assembly comprising an elongate sensor assembly, a tractor unit for transporting said elongate sensor assembly through a wellbore, and an orientation structure, the orientation structure and the tractor unit separately connected to the elongate sensor assembly, wherein
- the tractor unit comprises a main body comprising a first engagement structure to connect the tractor unit to the sensor assembly and substantially prevent relative rotation between the tractor unit and the sensor assembly, and one or more main wheels arranged to rotate about an axis of rotation substantially perpendicular to a longitudinal axis of the sensor assembly when the tractor unit is connected to the sensor assembly, and
- wherein the orientation structure comprises a second engagement structure to connect the orientation structure to the elongate sensor assembly and substantially prevent relative rotation between the orientation structure and the sensor assembly about the longitudinal axis of the sensor assembly,
- wherein the orientation structure defines a form that has a transverse outline which has a rotational centre offset from a centre of mass of the elongate sensor assembly so that in use the logging tool assembly is orientated in a most stable position with the centre of mass of the elongate sensor assembly below the rotational centre.
Dependencies are inferred from the claim text.