文昌油田水驱砂岩油藏驱油效率评价方法探讨

The Discussion Of The Displacement Efficiency Evaluation Methodology Of The Water Drive Sandstone Reservoir In the Wenchang Oilfield

文昌A油田高渗油藏目前实际采出程度67.9%,远大于早期岩心水驱油效率测定值57.21%,因此传统的驱油效率认识存在不合理性。而利用开发后期强水洗段岩心开展水驱油实验结果表明,文昌海相砂岩油藏水驱油效率可达81.73%。通过开展水驱油微观研究表明,水驱过程是对储层的改造过程,随着润湿性、孔喉结构、物性等性质的变化,水驱油效率是变化的。此文将驱油效率划分为静态驱油效率和动态驱油效率,提出用动态驱油效率来描述水驱砂岩油藏在不同阶段的水驱油效率,创新建立了以物理模拟与油藏工程方法相结合的动态驱油效率评价技术,研究成果表明动态水驱油效率是随着油藏水驱倍数的增加而逐渐增加。并将动态驱油效率应用于油藏数值模拟研究中,创新建立了两相渗流动态模型,在数值模拟中实现了非均匀驱替模式,更符合油藏的开发规律,实现了精细化数值模拟研究,提高了油田剩余油认识精度。

The actual recovery degree of the high permeability reservoirs in Wenchang A oilfield is 67.9% now, which is much larger than the measured value of early core water displacement efficiency of 57.21%. Therefore, the traditional water displacement efficiency is unreasonable, on the other hand, the core water displacement efficiency is 81.73% recently. The microscopic study of water flooding shows that, the water drive is a process of rebuilding the reservoir. With the changes of wettability, pore structure and property about reservoirs, the water displacement efficiency is changing. In this text, water displacement efficiency is divided into static state and dynamic state. The dynamic oil displacement efficiency is used to describe the water displacement efficiency in same stage of water drive sandstone reservoirs, and the artificial simulation and reservoir engineering methods are established combined with the dynamic oil displacement efficiency evaluation technology. The research results show that dynamic water displacement efficiency is gradually increased with water drive multiple increased. Finally, the dynamic water displacement efficiency is applied to the numerical reservoir simulation, and the two-phase fluid flow dynamic model is established.The non-uniformed displacement pattern is realized in the numerical simulation, which is more in line with the law of reservoir development, and the refinement numerical simulation research is realized to improve the understanding accuracy of oilfield residual oil.