普光气田采气地面流程水合物形成预测与防止技术

Formation prediction of hydrate in surface throttling process in Puguang Gasfield and its prevention measures

普光气田为高含硫中等含二氧化碳干气气藏,在地面节流过程中容易形成水合物而堵塞集输管线.因此进行了水合物形成预测.基于渗流理论、产能方程和节流原理,通过Wellflo软件模拟计算了普光2井在不同产气量下井口的温度和压力值,并计算了不同节流级数和不同节流压力下节流后的温度,据此预测了节流阀后管线中能否生成水合物.结果表明:普光气田节流过程中容易形成水合物;地面流程为两级节流时,应重视一级节流参数的合理选择.在此基础上提出了地面流程的节流原则和相应的水合物防止措施.

The natural gas in Puguang Gasfield has high content of sulfur and mediate content of carbon-dioxide dry gas.Therefore,hydrate is easily formed in surface throttling process,and it will plug gas transmission pipeline.For this reason,the formation of hydrate is predicted.Based on seepage theory,productivity equation and throttling principle,the wellhead temperature and pressure of Puguang 2 well under different gas production rates is calculated by using WELLFLO software,and the temperatures after throttling under different throttling orders and different throttling pressures are also calculated.According to the calculation results,it is predicted whether hydrate can be formed in the pipeline after throttling valves.The results show that,the hydrate is very easily formed in the throttling process,and therefore the first-order throttling parameters should reasonably be selected when two-order throttling is adopted.Some prevention measures from the formation of the hydrate are proposed.