高含硫湿气集输系统增压临界条件模拟

Simulation of the critical condition of pressurization for high sulfur wet gas gathering and transportation system

建立了高含硫湿气田增压集输模式的数值模型.采用热-力耦合计算方法,模拟分析了总站压力对段塞流风险、管段流速和管输能力的影响.研究结果表明:增压集输模式模型的可靠性误差均维持在9%以内;当气井配产不变时,总站压力越低,管道持液率越小.在后期开采中,管网运行压力的降低有利于避免段塞流的形成;当总站压力为5.0 MPa时,1^(#)、3^(#)、4^(#)均有部分管段流速过高,超过设计要求,需对相应管段进行增压集输,达到安全值;当集输管网满足90亿方/年的输送能力时,则总站运行压力不能低于6.9 MPa;确定了高含硫湿气集输系统增压运行的临界条件为不低于7.0 MPa.

A numerical model of pressurized gathering and transportation model for wet gas field with high sulfur content are established in this paper.The influence of terminal station pressure on slug flow risk,pipe flow velocity and pipe transportation capacity is simulated and analyzed in terms of the thermos-mechanical coupling method.All simulated results show:that the error for reliability of the pressurized gas gathering and transportation mode maintains within 9%.When the gas well distribution keeps unchanged,the lower the total station pressure is,the smaller the liquid holding rate of the pipe is.The decrease of the pipe network operating pressure is conducive to avoid the formation of slug flow in the later stage of exploitation.When the total station pressure is 5.0 MPa,some pipe sections,namely 1^(#),3^(#)and 4^(#),have flow rate of too high,which exceeds predetermined design requirements.Therefore,the corresponding pipe sections need to be pressurized for gathering and transportation to reach the safety value.When the gathering and transportation pipe network meets the transportation capacity of 9 billion square/year,the operation pressure of the main station shall not be lower than 6.9 MPa.It is determined that the critical condition for pressurized operation of high sulfur wet gas gathering and transportation system is not to be lower than 7.0 MPa.