Tubing centralizer

Abstract

The invention discloses a tubing centralizer which comprises a switch connection mechanism, a heat-insulation mechanism, a centering mechanism and a fixing mechanism. The heat-insulation mechanism comprises an inner center tube, an outer tube and a composite heat-insulation barrel, the outer tube is sleeved on the outside of the inner center tube, and the composite heat-insulation barrel is arranged in annular space formed by the inner center tube and the outer tube; the centering mechanism comprises a centering body, a centering block and an elastic centering plate spring, and the elastic centering plate spring is arranged in space formed by grooves of the centering body and grooves of the centering block; the maximum outer diameter of the centering block is larger than that of an insulated tubing on an injection string; a coupling of the switch connection mechanism is connected with the inner center tube of the heat-insulation mechanism in a threaded manner; and a fixing ring of the fixing mechanism is mounted at two ends of the outside of the outer tube and is connected to the outer tube in a threaded manner. The tubing centralizer has the advantages that the tubing centralizer is good in heat-insulation performance and has an excellent elastic centering function, a centralizing effect can be realized for the string, the heat-insulation performance of the integral injection string is improved, and requirements of production for injected high-temperature multi-element hot fluid or steam for offshore thick oil are effectively met.

Description

technical field [0001] The invention relates to heavy oil exploitation technology, in particular to a oil pipe centralizer used for high-inclination horizontal wells in offshore heavy oil thermal recovery. Background technique [0002] At present, horizontal wells are used for offshore heavy oil production, and due to the limited space of offshore platforms, the kickoff point basically starts at about 400 meters, the well inclination angle is relatively large, and the well structure is complex. In this way, during the injection of high-temperature multi-component thermal fluid (such as nitrogen + carbon dioxide + water vapor) or high-temperature steam production in thermal recovery horizontal wells, the entire injection string needs to take righting measures to ensure that the heat-insulated tubing collar does not contact the casing wall. Thereby reducing the heat loss caused by heat conduction due to the direct contact between the thermal insulation oil pipe collar and the ...

AI Technical Summary

Problems solved by technology

[0003] After the existing tubing centralizer is installed on the tubing string, although it plays the role of straightening the tubing string, because the steel body of the centralizing block of the tubing centralizer directly contacts the inner wall of the casing, the contact between the tubing centralizer and the casing is caused There is a high-temperature area, and the casing in this high-temperature area has the risk of high-temperature damage, and the conduction heat loss is much greater than the conduction heat loss caused by the contact between the insulated tubing collar and the casing wall

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