Oil-gas well gas-seal stage collar and assembly method thereof

Abstract

The invention discloses an oil-gas well gas-seal stage collar and an assembly method thereof. The stage collar comprises a body, a closing sleeve, a circumferential anti-rotation mechanism, a first clamping lock mechanism, a second clamping lock mechanism, an unlocking mechanism, a stage mechanism and a lower connector, wherein an outer stage hole is radially formed in a tube wall; the closing sleeve is arranged in the body, the closing sleeve is in sliding seal with the body, and an inner stage hole is radially formed in the tube wall of the closing sleeve; the circumferential anti-rotation mechanism is used for limiting circumferential relative displacement between the closing sleeve and the body; the first clamping lock mechanism is used for fixing the closing sleeve in a first position of the body; the second clamping lock mechanism is used for fixing the closing sleeve in a second position of the body; the unlocking mechanism is used for unlocking the first clamping lock mechanism; the stage mechanism is arranged in the closing sleeve; the lower connector is in sealing connection with the lower connecting end of the body, and outer connecting threads are formed on the lower end of the lower connector. Before staging, the closing sleeve is fixed in the first position, the inner and outer stage holes are opposite, and the inner stage hole is sealed by the stage mechanism; during staging, the inner stage hole is opened; after staging, the first clamping lock mechanism is unlocked, the closing sleeve moves downward to the second position, so as to be fixed, and the inner and outer stage holes are staggered. The oil-gas well gas-seal stage collar is convenient to assemble.

Description

technical field [0001] The invention relates to the technical field of oil and gas well cementing equipment, in particular to an oil and gas well gas sealing grading hoop and an assembly method thereof. Background technique [0002] At present, deep wells, ultra-deep wells, deviated wells, and horizontal wells of oil and gas wells are often cemented with gas-tight casings. At the same time, there is also a demand for gas-tight seals for the corresponding graded cementing tools. The promotion and application of gas-tight graded hoops will become an inevitable trend. However, the existing grading hoops are non-air-tight grading hoops, which do not have air-tightness capability, and the overall air-tightness effect cannot be improved by adding a transition joint. Moreover, the edge of the lock groove needs to be polished in order to fit into the lock ring during assembly of the existing grading hoop, thereby weakening the self-locking function. And when the closing sleeve is p...

AI Technical Summary

Problems solved by technology

However, the existing grading hoops are non-airtight grading hoops, which do not have the ability of air sealing. If the method of adding transition joints is used, the overall air sealing effect cannot be improved.

Moreover, the edge of the lock groove needs to be polished in order to fit into the lock ring during assembly of the existing grading hoop, thereby weakening the self-locking function

When the closing sleeve is put into the body, the sealing ring of the closing sleeve is easily scratched and damaged under the action of the internal thread and the relief groove of the body, resulting in seal failure and reduced sealing quality.

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