分流方程在塔河缝洞型油藏的应用

Application of fractional flow equation in fracture—cave typed reservoir of Tahe oilfield

建立裂缝-溶洞型油藏的储层模型后,采用受重力影响的分流方程,对影响含水率变化的因素进行了讨论,并得出以下结论:地下油水两相渗流特征明显不同于常规的单一介质油藏,含水率变化受重力的影响比较显著;裂缝-溶洞型油田开采过程中,如果生产压差略大于临界生产压差,只要稍微降低单井的生产压差,就可以大幅度地降低单井含水率,从而在理论上解释了间断关井能够压制底水锥进、减缓油井含水率上升趋势的原因。

Based on the simplified double porous media of frac- ture-cave typed carbonate reservoir,the fractional flow equation of fracture system under effect of gravity is brought up to analyze the contributing factors of water cut.The result shows that the characteristics of under- ground oil and water seepage in fracture-cave reservoir is quite different from that in homogeneous pore system dur- ing production period because the water cut is under great effect of gravity in fracture-cave reservoir.When the production pressure difference is not larger than the criti- cal pressure difference too much,and the production pres- sure difference is decreased slightly,the water cut can be decreased much rapidly,which explains why the closure of well leads to mild increasing trend of water cut change.