Patent ID: 7500526
Filing Date: 2009-03-10
Classification: E21B

Abstract:
1. A downhole tool for use in isolating a formation from fluid pressure introduced into a well bore, the tool comprising a body member connectable in a work string with an axial bore providing passage for fluid between an axial inlet and an axial outlet through the work string, a permanent sealing element located around the body member for contact with a wall of the well bore, one or more first radial outlets through the body on a first side of the sealing element and one or more second radial outlets located through the body on an opposite side of the sealing element, a plurality of valve members actuable sequentially to a) provide a first circulation path around the sealing element via the radial outlets and independent of the axial bore; (b) obstruct an axial flow path between the axial inlet and axial outlet, and provide a second circulation path from the axial bore through the first radial outlet; and (c) re-establish the axial flow path while maintaining the second circulation path.