Double-throttling-nozzle downhole throttling device

Abstract

The invention relates to a double-throttling-nozzle downhole throttling device used in the process of oil field gas well natural gas extraction. The problem that in the production process of a gas well, throttling nozzles need to be replaced under the well is solved. According to the technical scheme, an upper throttling nozzle is placed into a stepped hole in the lower portion of a central spindle, a pressing cap is connected with a stepped hole opening thread of the central spindle in a screwed mode, and a spring a is installed on a step in the middle of the outer circle of the central spindle. The central spindle, the upper throttling nozzle, the pressing cap and the spring a are integrally placed into an inner cavity of an upper center tube. An end cover is connected with the upper portion of the upper center tube in a screwed mode. The lower end of the end cover presses the spring a. A lower throttling nozzle is placed into a stepped hole in the upper portion of an inner hole of a lower center tube, the upper end of the lower center tube and the lower end of the upper center tube are connected in a screwed mode, and a spring d is installed on a step on the outer circle of the lower center tube. The upper end of a lower barrel and the lower end of an outer barrel are connected in a screwed mode. The upper portion of an upper conical tube and the middle of the lower barrel are connected in a screwed mode, and a seal rubber ring is installed on a step on the lower portion of the upper conical tube. When the yield of the gas well is changed, the size of a throttling hole is changed under the well through well-mouth pressure injection.

Description

technical field [0001] The invention relates to a downhole restrictor with double choke nozzles used in the natural gas exploitation process of oilfield gas wells. Background technique [0002] In the process of natural gas development, the pressure in the gas well is relatively high, and a throttling and pressure-reducing device must be installed to control the gas production of the gas well in order to achieve the goal of stable production. In the process of throttling and pressure reduction, the pressure of natural gas drops rapidly after passing through the throttle nozzle, and the volume expands rapidly, resulting in a decrease in the temperature of natural gas. However, natural gas usually contains a certain proportion of water. When the temperature of natural gas drops to the conditions for hydrate formation, hydrates will condense, and hydrates will block production strings and surface pipelines, seriously affecting the normal production of gas wells. [0003] The d...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a downhole choke with double choke nozzles in order to solve the problem of downhole replacement of choke nozzles in the gas well production process.

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