低渗气藏带节流器水平井积液预测模型

近年来,水平井技术已在低渗气藏的开发过程中得到广泛运用,但水平井在生产状态下准确预测井筒积液的问题,目前仍没有得到较好地解决。通过对低渗气藏水平井单相渗管耦合的理论研究,考虑了气液两相流动及井筒摩擦损失,建立了新的低渗气藏水平井气液两相渗管耦合模型,并以此推导出了水平井井筒积液量的计算公式。然后,以井口套压为约束,结合几何转换建立了环空积液量计算方法。最后,以环空算出的井底压力约束,联立各模型,建立了水平井积液预测模型。同时,通过程序编译和流体软件模拟分别对苏里格气田某井区单井的直井段和水平段的积液量进行了计算,与实际积液情况符合较好。结果显示,该预测模型不仅可在气井正常生产时较为准确地预测井筒积液量,且该方法也能为其他类似气藏的水平井积液研究工作提供新的思路。

A method for calculate liquid volume of horizontal well which installed control choke of low permeability gas reservoirs

In the latest years, horizontal well technology had been widely used in developing low permeability gas reservoir. But the problem that the liquid volume prediction of horizontal wells which on startup state still has not been solved satisfactorily. Aiming at the problem, this paper analyzed the theory of single phase coupling flow of horizontal wells in low permeability gas reservoir, and considering the air-water two phase flow and the friction loss of wellbore, built a new air-water two phase coupling flow of horizontal wells, and deduced an equation which can calculate the liquid volume of horizontal well. Then with casing pressure as the constraint condition, combine with geometric transformations, the method for calculating the liquid volume of annular was established. And finally, with the bottom hole pressure which calculated by annular liquid predicting model as the constraint condition, a method for calculating the liquid volume of horizontal wells was established. At the same time, using the program compilation and the software simulation validated the liquid volume of vertical section and horizontal section of gas wells in Sulige, respectively. And the results correspond with the actual situation, it shows that the method has a good ability to predict fluid volume of horizontal wells, and this study can also offer a new idea for other similar gas reservoirs to research the liquid prediction of horizontal wells.