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.