Underground spiral flow tubular column for separately exploiting gas and liquid and system analysis method

Abstract

The invention belongs to the technical field of oilfield exploitation and discloses an underground spiral flow tubular column for separately exploiting gas and liquid and a system analysis method. Byutilizing a suspended speed oil tube in an oil tube, a gas-liquid lifting channel is built; by setting a split ratio, after gas and liquid flow through a spiral flow gas-liquid separator, the gas production amount and exit pressure of a gas-phase outlet and the liquid production amount, gas content rate and exit pressure of a liquid-phase outlet are calculated separately; pressure loss and critical liquid-gas loading amount after the gas passes through a gas nozzle are figured out through iterative computation to judge whether or not the speed oil tube meets the requirements for loading liquid. By setting electric pump feature parameters, pump discharge pressure and the annulus pressure loss of an on-way oil tube and the speed oil tube are figured out through the iterative computation until the pressure of an inlet of a gas-liquid mixing device is approachable to the pump discharge pressure; finally, the pressure loss between the on-way oil tube and a wellhead is figured out through the iterative computation until oil pressure is higher than flow backpressure. The technological tubular column has the advantages that convenience is provided for operation and construction, and the working stability is high. The system analysis method of the tubular column is clear in thinking pattern, reliable in computing approach and simple in system coordination control and can be widely applied to hoisting processes for marine oil wells with a high gas-liquid ratio.

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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