低渗透油藏水平井流入动态关系的建立

Establishment of inflow performance relationship of horizontal wells in low-permeability reservoir

采用等值渗流阻力法,推导出了低渗油藏水平井稳定渗流产量公式、溶解气驱油气两相流产能方程及无因次流入动态方程。流入动态方程简单明了,与Wiggins方程形式一致。产能影响因素分析结果表明:中高渗油藏的流动是启动压力梯度为零的低渗油藏流动的一个特例;随着启动压力梯度的增加,水平井产能明显递减;水平井长度越长,产量越大。

The productivity equations in steady fluid flow and off-gas two-phase flow with solution gas drive of horizontal wells in low-permeability reservoirs were established by equivalent flowing resistance method. And the dimensionless inflow performance relationship of horizontal wells was given. The equations of inflow performance relationship are simple and clear, and correspond with Wiggins equations. The results show that the flow in middle and high permeability reservoirs is only a special case of flow in low-permeability reservoirs when the starting pressure gradient equals to zero. The productivity for horizontal wells in low-permeability reservoirs decreases with the starting pressure gradient increasing. And the productivity for horizontal wells increases evidently with the length of horizontal well increasing.