摘要 |
<p>A system (10,100) for isolating a wellbore (12,112) having a fluid flow passage (18,118) extending from surface to a subterranean location has a first, downhole, valve (20,120) and a second, uphole, valve (22,122). The downhole valve (20,120) is located in the wellbore (12,112) at a first subterranean location and the uphole valve (22,122) is located in the wellbore (12,112) at a second subterranean location spaced from the first valve (20,120). Downhole valve (20,120) is operable between a first configuration which permits access through the flow passage (18,118) and a second, well isolation, configuration which isolates the flow passage (18,118) below the valve (20,120). Uphole valve (22,122) is operable between a first configuration which permits access therethrough and a second, isolation, configuration which provides an isolated or isolatable volume (24,124) between the first and second valves (20, 22,120,122). A pressure sensor (26,126) is disposed in the isolated volume (24,124) between the downhole valve (20,120) and the uphole valve (22,122) and, in use, the pressure sensor (26,126) permits a pressure P1 in the isolated volume (24,124) to be measured and/or communicated to a remote location (30).</p> |