Downhole tool string braking

摘要

A braking apparatus for a tool string positionable in a wellbore and a method of braking a tool string in a wellbore is disclosed. The braking apparatus includes: a tubular housing having at least one radial arm-bay opening; an actuating mechanism including: a wedge member mounted in an internal cavity of the housing; an axial guide rod coupled at one end to the wedge member; and a push-pull device. The push pull device includes: a biasing member casing through which the guide rod extends to contact the wedge member, a biasing member; and at least one braking arm pivotably mounted to a lower portion of the biasing member casing, wherein when the biasing member casing of the push-pull device in in a lowered position, the braking arm bears on a sloped surface of the wedge member to project the braking arm into contact with a wellbore wall.

主权项

1. A braking apparatus for a tool string positionable in a wellbore, the braking apparatus comprising:
a tubular housing having a cylindrical side wall defining at least one radial arm-bay opening; an actuating mechanism including:
a wedge member mounted in an internal cavity of the housing;an axial guide rod coupled at one end to the wedge member; anda push-pull device including:
a biasing member casing having an upper axial opening and a lower axial opening through which the guide rod extends to contact the wedge member, the biasing member casing slidably positioned on the guide rod;a biasing member located within an internal cavity of the of the biasing member casing, the biasing member biasing the biasing member casing toward a lowered position in the tubular housing; and a linkage member attached to the biasing member casing and connectable directly to a suspension line or indirectly via other tool string elements to the suspension line; and at least one braking arm pivotably mounted to a lower portion of the biasing member casing, and wherein when the biasing member casing of the push-pull device is in the lowered position, the braking arm bears on a sloped surface of the wedge member to project the braking arm through the radial arm-bay opening of the tubular housing.