Variable outside diameter tool for use in pikewells

摘要: An apparatus for use in energy exploration is disclosed which used where a radially expanding device required, example stabilizer, retriever or an underreamer. The comprises support tubular member connection to drilling string, the supporting movable axially along member. A further may either be fixedly secured also spaced from and, optionally, have tapered outer surfaces cooperate with taper on arrangement such that movement of axial direction cooperating tapers cause expand contact radial direction. Various means securing and performing are disclosed.