深层凝析气井临界携液模型优化研究

Study on Optimization of Critical Fluid Carrying Model for Deep Condensate Gas Well

以Turner模型为代表的临界携液流量模型在预测积液位置和表面张力方面均存在不足,导致积液预测结果与凝析气井实际情况偏差较大。为提高积液预测精度,考虑临界携液流量和表面张力沿井筒的差异分布,取井筒中临界携液流量的最大值作为积液判断标准,并根据不同温度、压力条件计算对应的表面张力。同时,考虑井筒中存在气体、凝析油和地层水三相,建立凝析气井井筒温压耦合计算模型。实例验证表明,改进后的4种临界携液流量模型与原始模型相比,均提高了积液预测精度,其中改进的李闽模型预测精度提高的幅度最大,预测精度最高,适合于雅克拉—大涝坝深层凝析气井的积液预测。该研究对现场开展积液判断和排液工艺优选具有指导意义。

The critical fluid carrying flow model represented by Turner model has some disadvantages in predicting the liquid loading location and superficial tension,resulting in great deviation of predicted liquid loading result from the actual condition of condensate gas well. For the sake of improving the liquid loading prediction precision,this paper considered the differential distribution of critical fluid carrying flow and superficial tension along the borehole,took the maximum value of critical fluid carrying flow in the borehole as the liquid loading judgment criterion,and calculated the corresponding superficial tension based on different temperature and pressure conditions. Simultaneously,in view of the existence of gas,condensate oil and formation water in the borehole,this paper built a temperature and pressure coupling computation model for the borehole of condensate gas well. Case verification showed that compared with the original model,all the 4 improved critical fluid carrying flow models had improved the liquid loading prediction precision,among which,the improved Li Min model not only had furthest improved the prediction precision,but also had the highest prediction precision,and it was suitable for predicting the liquid loading in deep condensate gas wells of the Yakela- Dalaoba area. It has guidance significance to the field judgment of liquid loading and the optimization of liquid unloading process.