Downhole reference device expanded by the insertion of a wedge into a slot

摘要

A tubular body 10 is expanded into contact with the borehole casing 15 by the insertion of a wedge 19 into a slot in the body. The body may serve as a location reference within the casing and may include an arrangement for orienting well tools. Preferably, the slot is tapered and complementary to the wedge and the outside of the body is roughened or has discrete teeth (figure 5) to engage the casing. A piston on a setting tool may actuate the wedge. Also disclosed is a method for setting a marker in a borehole involving orienting a reference member having a contoured upper surface 17, fixing the reference device by expanding it into engagement with the casing, and using the contoured surface to orient a locator device prior to performing an operation with a well tool.