Downhole apparatus and method

摘要

A downhole apparatus (410) is described comprising a body (412) and a sealing arrangement located on the body. The body has a longitudinal axis and the sealing arrangement comprises at least one elongated sealing member (330) with an axis of elongation extending around the longitudinal axis. The sealing member (330) comprises a material selected to expand on exposure to at least one predetermined fluid, such as a hydrocarbon or aqueous fluid encountered in a wellbore.