Patent ID: 7059415
Filing Date: 2006-06-13
Classification: E21B

Abstract:
1. A wellbore system, comprising: a borehole extending into an earth formation; a tubular element extending into the borehole whereby a cylindrical wall surrounds the tubular element in a manner that an annular space is formed between the tubular element and the cylindrical wall; and at least one seal member arranged in said annular space, each seal member being movable between a retracted mode in which the seal member has a first volume and an expanded mode in which the seal member has a second volume larger than the first volume, wherein the seal member in the expanded mode thereof seals the annular space, and wherein the seal member includes a material, which swells upon contact with hydrocarbon fluid and a material, which swells upon contact with water so as to move the seal member from the retracted mode to the expanded mode thereof.