Downhole activatable annular seal assembly

摘要

A system for providing an active pressure differential within a wellbore, the system comprising an active pressure differential device having an outer housing 702 and a fluid pump component and an annular seal assembly 718 for providing a fluid seal between the housing 702 of the active pressure differential device and a wellbore sidewall. The seal assembly 718 comprises a seal element 668 that is set against the wellbore sidewall to provide a fluid seal, and a fluid passage 714 that allows wellbore fluids to bypass the seal element 718 as the active pressure differential device and annular seal assembly 718 are run into the wellbore. The seal assembly also comprises a sleeve element that is shiftable to selectively preclude fluid flow through the fluid passage. The application also discloses a system for providing an active pressure differential comprising a seal element that is radially set against the wellbore sidewall by a spring.