烃源岩压实渗流排油模型

Compaction-filtration model for oil expulsion in source rocks

提出了烃源岩油水两相系统相对渗透率计算公式 ,与逐次沉积压实排液的原理相结合 ,建立了新的排油模型 (简称压实渗流模型 )。该模型与原有纯压实模型相比 ,主要优点是 :①取消了纯压实模型中基于排液前的油水之比与排液量中的油水之比相等的粗略假设 ,使排液量中的油水之比由油水两相的相对渗透率和粘度来确定 ,从本质上改善了地质模型的合理性 ;②克服了纯压实模型因前期排油过早、过大及后期偏小的缺点 ,大大提高了排油史的模拟精度 ,从而确保随后对油运、聚史的模拟真实性。两种模型在库车坳陷进行了对比应用 。

The formulas for calculating relative permeability of oil-water two-phase in source rocks were presented. In combining with the principle of successive sedimentary compactions new oil expulsion model known as the compaction-filtration model was established. Compared to the old pure compaction model, the compaction-filtration model has two major advantages. Firstly, it does not use the inaccurate assumption that the ratio of oil to water before liquid expulsion equals that in expelled liquid, and the ratio of oil to water in expelled liquid can be determined by the relative permeability and viscosity of oil and water. This model reasonably improved the geological model. Secondly, it overcomes the shortcoming of the pure compaction model whereby the oil expulsion started too early and the expelled amount of oil was too large in the early stages and too small in the late stage. This improvement greatly enhances the accuracy of oil expulsion simulation and ensures the reality of following oil migration-accumulation history simulation. The applied case comparison of the old and new models in Kuqa Depression proves the rationality and practicability of the compaction-filtration model.