Patent ID: 11156043

Abstract:
A method of controlling a well in a geological structure, the well comprising: a first casing string (12a), and a second casing string (12b) at least partially inside the first casing string thus defining a first inter-casing annulus therebetween. A primary fluid flow control device (16a), such as a wirelessly controllable valve, is provided in the second casing string (12b) to provide fluid communication between the first inter-casing annulus (14a) and a bore (14b) of the second casing string (12b). In the event of well “blow-out”, a relief well (40) may be drilled and a fluid communication path formed between the relief well and the first casing string of the well rather than extend to lower and/or narrower sections of casing. A kill fluid can then be introduced via the relief well (40) and the primary fluid flow control device (16a) used to direct fluid to the second casing bore (14b). Further casing strings (12c) may be part of the well, and include corresponding flow control devices (16b), allowing the kill fluid to cascade down the well to control it. Accordingly, the time taken to drill a relief well to a shallower depth than is conventional can reduce the time and cost to control the well and can mitigate environmental impact of hydrocarbon loss caused by the blow-out.