利用反向推理方法确定水驱特征曲线渗流方程

Determination of seepage equation of water drive characteristic curve by reverse derivation method

高文君 刘致远 薛龙龙1

中国石油吐哈油田分公司勘探开发研究院，新疆 哈密 839009 中国石油吐哈油田分公司监督中心，新疆 鄯善 838202

建立油水两相渗流特征与水驱特征曲线对应关系，揭示水驱特征曲线宏观规律中蕴含的微观渗流特征，一直是油藏工程长期性基础研究课题，目前已初步形成从油水相渗比值到水驱特征曲线的正向推理方法。但受现有油水相渗比值研究成果限制，已有水驱特征曲线的理论推导一直未能获得突破。为此，文中借鉴反向推理实现目标性较强的特点，提出了利用反向推理方法来确定水驱特征曲线渗流理论基础，并对推理过程中的关键数学逻辑式进行函数特征分析。结果表明，反向推理数学逻辑更加可行、严密，完全可实现油水渗流特征微分方程的求解，所得到的油水相渗比值关系式属超越方程，该结果也能完美地应用到正向数学逻辑推理中。将其应用于大庆南二、三开发区葡Ⅰ组油藏，从实际生产数据确定的油层油水渗流特征与实验测试得到的结果一致。这也为研究油藏水驱过程中实际油水渗流特征提供了新的思路与方法。

It has been a long-term basic research topic in the field of reservoir engineering to establish the corresponding relationship between oil-water two-phase seepage characteristics and water drive characteristic curves and reveal the micro seepage characteristics contained in the macro laws of water drive characteristic curves. At present, the forward derivation method from oil-water relative permeability ratio to water drive characteristic curve is initially formed. However, due to the limitations of existing research results on oil-water relative permeability ratio, there has been no breakthrough in the theoretical derivation of the existing water drive characteristic curves. For this reason, this paper uses the characteristics of reverse derivation to achieve a better goal, puts forward the use of reverse derivation method to confirm the seepage theory of water drive characteristic curve, and analyzes the function characteristics of key mathematical logic formula in the process of derivation. The results show that the reverse derivation mathematical logic is more feasible and rigorous, which can completely achieve the solution of the oil-water seepage characteristic differential equation. The formula of oil-water relative permeability ratio belongs to transcendental equation, which can be applied to forward mathematical logic derivation perfectly. By applying the result to PuⅠreservoir of the No. 2+3 southern region in Daqing oilfield, the oil-water seepage characteristics obtained from the actual production data are consistent with the experimental results, which also provides a new idea and method for the study on oil-water seepage characteristics in the process of reservoir water drive.

10.6056/dkyqt202004014