水驱砂岩油藏水平井开发技术研究

Research on horizontal well development technology in waterflooding sandstone reservoir.

根据渗流阻力原理，采用保角变换和镜面反映方法，得到水驱砂岩油藏中水平井的产能公式，据此公式计算出在水平段长度为５０～６００ｍ之间时，水平井与直井的产量倍数关系在１．４～９．８之间。对不同断块的两口水平井开发指标进行了计算，计算结果与实际数据相符，可以应用于水平井的动态分析。研究表明在水平段长度相同的情况下，低渗油藏的增产倍数高于高渗油藏。还讨论了储层物性、注采方式、注采压差对水平井生产效果的影响，指出在优化注采井网条件下，水平井保持能量生产，开发效果较好。水平井的注水方式及注水压力对油藏最终采收率起着决定性影响，注采压力梯度应维持较低水平，一般小于０．０９ＭＰａ／ｍ为宜。

Based on the principle of percolation resistant and the method of conformal transformation and mirror image, this paper derived the horizontal oil productivity formula in waterflood sandstone reservoir.While the horizontal length is 50～600m, the production calculating by this formula in horizontal is 1 4～9.8 times over that in vertical well. Two horizontal wells development index in different fault blocks have been calculated and the values matched the field data, so they can be used to horizontal well performance analysis. In the case of same horizontal section, the oil production increase in low permeability reservoir is more than that in high permeability reservoir. This paper also discussed the reservoir petrophysics, injection production pattern and differential pressure effecting on the horizontal well production, the horizontal well development result is better as optimization injection production well pattern and pressure maintaining ; The injection pattern and pressure have effect definitely on the reservoir ultimate recovery, the pressure gradient should be maintained low, it had better be below 0.09 MPa/m in common.