低渗透油藏中多维定常渗流特征研究

Low-permeability reservoir studies of multi-dimensionally definite flow and percolation characteristics.

方法 应用达西定律 ,研究低渗透油藏中多维定常渗流特征。。目的 通过对低渗透油藏不定常渗流特征研究 ,提高利用垂直裂缝井和水平井开发低渗透油藏的能力。结果 对低渗透直井来说 ,生产压差与采油指数成正比 ,当生产压差较大时 ,采油指数变化趋于平稳 ,启动压力梯度越大 ,采油指数越小 ;对垂直裂缝井来说 ,启动压力梯度越大 ,产量越小 ,裂缝越长 ,产量及采油指数越大 ;对水平井来说 ,启动压力梯度越大 ,产量越小 ,水平井长度与产量成正比 ,采油指数与水平井长度及生产压差成正比 ,当生产压差较大时 ,采油指数变化趋于平缓。结论 酸化措施可有效地提高直井的产量 ;垂直裂缝井和水平井的采油指数远大于直井 ,说明垂直裂缝井和水平井开发低渗透油藏优于直井。

Method\ The multi-dimensionally definite flow and retention characteristics of low-permeability reservoirs is studied by using Darcy's law. Purpose\ To increase the capability of developing low-permeability reservoirs with vertically fractured and horizontal wells. Result\ Production pressure drop is proportional to oil production index for low-permeability vertical wells. When the production pressure drop is large, the index variation tends to be smooth. The larger the starting pressure gradient, the smaller the index is. For vertically fractured wells, the larger the starting pressure gradient, the smaller is the production; the longer the crack, the larger is the production and the index. For horizontal wells, the larger is the starting pressure gradient, the smaller is the production, the length of the horizontal well is proportional to the production, the index is proportional to the length and the production pressure drop. When the production pressure drop is larger, oil production index variations tend to be gentle. Conclusion\ Acidizing can effectively increase the production of vertical wells; the fact that the oil production index of vertically fractured wells and horizontal wells is much larger than that of vertical wells shows development of low-permeability reservoir by vertically fractured wells and horizontal wells is better than vertical wells.