A downhole swirling gas-liquid separation production string and system analysis method

Abstract

The invention belongs to the technical field of oilfield exploitation, and discloses a downhole swirling flow gas-liquid separation string and a system analysis method. The gas-liquid lifting channel is established by using the suspended velocity oil pipe in the oil pipe, and the flow through the swirl is respectively calculated by setting the split ratio. The gas production rate and outlet pressure at the gas phase outlet after the flow gas-liquid separator, the liquid production rate, gas content rate and outlet pressure at the liquid phase outlet; through iterative calculation of the pressure loss and critical liquid-carrying gas volume after passing through the gas nozzle, it is judged whether the velocity column meets the requirements. Liquid-carrying requirements; by setting the characteristic parameters of the electric pump, iteratively calculate the pump outlet pressure and the annulus pressure loss of the tubing and velocity tubing along the way until the inlet pressure of the gas-liquid mixer is similar; finally iteratively calculate the pressure loss of the tubing along the way to the wellhead until The oil pressure is greater than the process back pressure to end. The process pipe string of the present invention has the characteristics of convenient operation and construction and high working stability. Its system analysis method has clear ideas, reliable calculation methods, and simple system coordination and control, and can be widely used in the lifting process of offshore high gas-liquid ratio oil wells.

Description

technical field [0001] The invention relates to the technical field of oilfield exploitation, in particular to a novel downhole swirling gas-liquid separate recovery pipe string and a system analysis method based on the pipe string. Background technique [0002] Offshore oilfields with high gas-liquid ratio oil wells (gas content > 60%) face problems such as low lifting efficiency of conventional electric pump wells, and in severe cases, "gas lock", which seriously affects the normal production of oil wells. At present, there are three commonly used lifting methods for oil wells with high gas-liquid ratio in offshore oilfields: 1) The conventional gas-liquid separator is suitable for well conditions where the gas content at the pump suction inlet is less than 30%; 2) The gas separation master can handle the pump suction inlet When the gas content is 30%-50%, the separation efficiency drops significantly when the gas content increases. 3) The gas processor compresses the ...

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Problems solved by technology

[0005] The present invention aims to solve technical problems such as low lifting efficiency of conventional electric pump wells in offshore oil fields with high gas-liquid ratio oil wells, "air lock" and low lifting efficiency in severe cases, and provides a downhole swirling gas-liquid separation The pipe string and system analysis method, the process string has the characteristics of convenient construction and high work stability, the system analysis method has clear thinking, reliable calculation method, simple system coordination and control, and can be widely used in offshore high gas-liquid ratio oil wells Lifting process

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