Polymer flooding is a well-established chemical method for enhancing oil recovery in sandstones; however, it has a limited application in carbonates. This is due to the harsh reservoir conditions in carbonates including high temperature, high salinity, and high heterogeneity with low permeability. This paper numerically investigates the effect of Schizophyllan biopolymer on oil recovery from carbonates. The effect of biopolymer on oil recovery was predicted by running several 1D simulations. Biopolymer flow behavior was modeled based on experimental data. The results showed that the effect of the investigated biopolymer on oil recovery was not much pronounced compared to conventional waterflooding. This is due to small-scale heterogeneity, which increased effective shear rate and hence, decreased in-situ polymer viscosity. Formation permeability, polymer viscosity, and oil saturation maps were consistent in justifying this observation. The findings of this study were supported by fractional flow and mobility ratio analyses. This work highlights the importance of small-scale heterogeneity of the core in modeling polymer flooding, particularly the shear effect on polymer viscosity.

中文翻译：

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小规模异质性对碳酸盐生物聚合物性能的影响

聚合物驱是一种完善的化学方法，可以提高砂岩中的石油采收率。但是，它在碳酸盐中的应用有限。这是由于碳酸盐岩中苛刻的储层条件，包括高温，高盐度和低渗透率的高非均质性。本文数值研究了裂褶多糖生物聚合物对从碳酸盐中采油的影响。通过运行几个一维模拟可以预测生物聚合物对采油量的影响。基于实验数据对生物聚合物的流动行为进行建模。结果表明，与常规注水相比，所研究的生物聚合物对石油采收率的影响并不明显。这是由于小规模的非均质性，提高了有效剪切速率，因此降低了原位聚合物的粘度。地层渗透率 聚合物粘度和油饱和度图在证明该观察结果方面是一致的。这项研究的结果得到了分数流率和迁移率比分析的支持。这项工作强调了在聚合物驱模型中岩心的小范围非均质性的重要性，特别是对聚合物粘度的剪切作用。