遗传算法在致密砂岩储层渗透率计算公式优化中的应用—以鄂尔多斯盆地环县地区延长组长8段为例

Application of Genetic Algorithm to the Optimization of the Calculation Formula for Permeability of Tight Sandstone Reservoir:Taking the Number 8 of the Yanchang Formation of Huan County Oilfield in Ordos Basin as an Example

鄂尔多斯盆地环县地区延长组长8段为典型的低孔隙度低渗透率致密砂岩储层.由于其孔隙结构复杂、非均质性较强,因而对其渗透率的分析预测是该区储层研究的难点,结合环县地区长8储层的具体地质特征和测井曲线类型,利用遗传算法全局寻优的特点,建立了适合本地区致密砂岩储层渗透率计算的公式.研究表明,使用公式预测的渗透率与利用岩心分析的渗透率结果有较高的符合率.因此,遗传算法在致密砂岩储层渗透率计算公式的研究中具有很好的应用前景.

The number 8 in Huan county of Ordos Basin is a typical tight sandstone reservoir with low porosity and permeability.Due to the complexity of pore structure and heterogeneity of the reservoir,it is more difficult to analyze and predict its permeability compared with other studies concerning the reservoir in this area.The optimal calculation formula for the permeability of tight sandstone reservoir is found by utilizing the genetic algorithm,based on the geological features and logging curves of number 8 reservoir in Huan county.The results show that the data produced by the optimal calculation formula for permeability is highly consistent with that produced by well core analysis.Therefore,such method is of very good application value to study the calculation formula for permeability of tight sandstone reservoir.