Downhole apparatus with a swellable centraliser

摘要

A downhole apparatus, for example a centralizer, comprises a swellable material which expands upon contact with at least one predetermined fluid. In a first aspect of the invention, a centralizer comprises a body and a plurality of formations upstanding from the body. In another aspect, a downhole apparatus comprises a throughbore configured to receive a tubular, a swellable member, and a rigid assembly integrally formed with the swellable member. The rigid assembly provides stand off to the apparatus in use. In a further aspect, the downhole apparatus has a first condition before expansion of the swellable member in which a rigid assembly defines a maximum outer diameter of the apparatus. In a second condition after expansion of the swellable member, the swellable member defines a maximum outer diameter of the apparatus. In a preferred embodiment, the rigid assembly is designed to flex or deform under an axial or radial load.

主权项

1. A centraliser for a downhole tubular, the centraliser comprising:
a body; a plurality of formations upstanding from the body and circumferentially spaced apart around the body; and a swellable member, comprising a swellable material selected to expand on exposure to at least one predetermined fluid, disposed on an outer surface of the body and between the plurality of formations and the tubular.