塔河12区缝洞型油藏剩余油分布数值模拟研究

Numerical Simulation Study on Remaining Oil Distribution of Fractured Vuggy Reservoir in Block 12 of Tahe Oilfield

摘要: 塔河12区油藏是典型的缝洞型油藏，前期采速高，产量下降快，剩余油分布十分复杂。为研究剩余油分布情况，提炼了三种典型缝洞结构模型，分别是双溶洞左右排列组合模型、表层岩溶缝洞组合模型和双溶洞上下排列组合模型。采用Fluent软件模拟探究了缝洞结构差异性、生产压差、注采方式、注水速度和缝洞连接位置对剩余油分布的影响。结果表明，不同的缝洞结构模型在注水开发后，剩余油分布情况差异较大，且受其他开发参数的影响程度不同。生产压差对剩余油分布无明显影响；溶洞低注高采具有更好的开发效果，剩余油分布也更加集中；较高的注水速度下采收率更高；缝洞连接部位对剩余油分布有一定影响。此外，针对主要的剩余油分布类型给出了相应的挖潜建议。

Abstract: The reservoir in block 12 of Tahe oilfield is a typical fractured vuggy reservoir. The recovery rate is high in the early stage. The yield decreased rapidly. The distribution of remaining oil is very complex. In order to study the distribution of remaining oil, three typical fractured vuggy models are extracted. They are respectively double vugs model of left and right permutation and combination, fractured vuggy model of epikarst combination and double vugs model of up and down permutation and combination. Using FLUENT software, the influence of fractured vuggy structure difference, production pressure difference, injection and production method, water injection rate and fractured vuggy connection position on the remaining oil distribution was explored. The results show that the distribution of remaining oil varies greatly among different fractured vuggy structure models after water injection development, and the influence of other development parameters on the distribution of remaining oil varies. The production pressure difference has no obvious effect on the remaining oil distribution. Compared with water injection in high position and mining in low position, water injection in low position and mining in high position have better development effect. In that case, the distribution of remaining oil is more concentrated. Higher water injection rates lead to higher recovery. The location of the connection between the vug and the fracture has a certain influence on the distribution of the remaining oil. In addition, the corresponding suggestions for exploiting the remaining oil distribution types are given.