| 摘要 |
A swellable apparatus for filling a space in oil or gas tool such as a wellbore packer is described. The swellable apparatus comprise a hydrocarbon swellable body which swells on exposure to a hydrocarbon fluid, and at least one water swellable body which swells on exposure to a second fluid comprising water. The hydrocarbon swellable body is interposed between the aqueous fluid and the water swellable body and comprises at least one access pathway configured to permit the passage of water to the water swellable body. The pathway may be formed by perforation, or by incorporating an additive into the hydrocarbon material, such as a foaming agent or polyoctenamer. Embodiments of the invention comprise variations in cross-linking in the hydrocarbon swellable body. |
