SECTION OF HEAT-INSULATED STRING Russian patent published in 2013 - IPC E21B17/00 

FIELD: oil and gas industry.

SUBSTANCE: section contains inner tube with reinforcement at the ends, centring skids, insulation and gas absorbers. Also the section contains outer tube with male screw at ends and tubing collar. Outer tube is designed with air-tight valve ensuring creation of vacuum 10^-4-10^-3 mm hg in annular space. In annular space there are steel linings in the form of bushings. Lining are welded to inner and outer tubes by vacuum-tight welds. To outer tube linings are welded at the point of male screw placements at ends within area under the section from the first turn till base plane of thread. In annular space linings are located so that grove in the lining and outer tube form a cavity. Centring skids are made as clamps consisting of two parts interconnected rigidly. Inner surface of centring skids is designed with friction properties.

EFFECT: reduction of heat losses during heat carrier passage through the string and increase of operational efficiency for the string.

1 cl, 3 dwg