地质约束条件下的致密储层地质建模研究——以七里村油田柴上塬区长6油层组为例

Study on Geological Modeling of Tight Reservoirs under Geological Constraints:A Case Study of Chang 6 Reservoir in Chaishangyuan Area of Qilicun Oilfield

为了提高三维地质模型与地质认识耦合程度,提出一种基于地质约束的致密储层地质建模思路:结合区域构造背景,精细研究构造特征,建立地层格架;确定砂岩、泥岩、夹层的地球物理响应特征;建立地质知识库;优选建模方法与分析变差函数特征值;建立精细地质模型。以七里村油田柴上塬区为例,综合利用录井、测井、产量等实测资料及压汞等实验测试资料,对密井网砂体连井剖面进行精细研究,明确砂体、隔层空间分布规律及储层物性特征,基于地质认识建立地质知识库,针对研究区储层非均质性强的特征,提出变差函数选取、特征值分析方法。基于地质约束的建模结果显示,建模地质储量与油田容积法计算的地质储量仅相差1.2%,孔隙度、渗透率、含油饱和度分布特征建模前后一致。

In order to improve the consistency between 3D geological model and geological understanding,a geological modeling idea for tight reservoirs based on geological constraints is proposed:Studying carefully the structural characteristics and establishing the stratigraphic framework based on the regional tectonic background;Determining the geophysical response characteristics of sandstone,mudstone and interlayer;Establishing geological knowledge base;Optimizing modeling methods and analyzing eigenvalues of variogram;Establishing fine geological model.Taking Chaishangyuan area of Qilicun oilfield as an example,the well connection profile of sand bodied in dense well pattern is carefully studied by comprehensively using the measured data such as mud logging,logging and production data and the experimental data such as mercury injection,so as to clarify the spatial distribution law of sand bodies and interlayers and the physical property characteristics of reservoir.The geological knowledge base is established based on geological knowledge.The methods for variation function selection and eigenvalue analysis are proposed according to the characteristics of strong reservoir heterogeneity in the study area.The modeling results based on geological constraints show that the difference between the geological reserves obtained by modeling and the geological reserves calculated by oilfield volume method is only 1.2%,and the distribution characteristics of porosity,permeability and oil saturation are consistent before and after modeling.