CPC E21B 33/143 (2013.01) [E21B 17/14 (2013.01); E21B 33/16 (2013.01); E21B 43/101 (2013.01)] | 20 Claims |
1. A method of locating bore-lining tubing in a drilled bore, the method comprising:
selecting a buoyant material having a density lower than the density of an ambient fluid filling a drilled bore;
locating the buoyant material in a bore-lining tubing;
locating an inner tubing within the bore-lining tubing, with the inner tubing extending from a distal end of the bore-lining tubing to a proximal end of the bore-lining tubing and defining an inner annulus between the inner tubing and the bore-lining tubing;
coupling and sealing a distal end of the inner tubing to the distal end of the bore-lining tubing by engaging a coupling on the inner tubing with a coupling on the bore-lining tubing;
sealing the inner tubing to a portion of the bore-lining tubing at a location spaced from the distal end thereof to isolate a portion of the inner annulus between the distal end and the sealing location;
retaining a volume of the buoyant material within the isolated portion of the inner annulus and running an assembly comprising the inner tubing and the bore-lining tubing and containing the volume of buoyant material retained within the isolated portion of the inner annulus into the ambient fluid-filled drilled bore;
flowing fluid through the inner tubing and into an outer annulus surrounding the bore-lining tubing while containing and retaining the volume of buoyant material within the isolated portion of the inner annulus; and
opening a port in the distal end of the inner tubing and flowing fluid between the inner tubing and the inner annulus via the port.
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