基于交叉验证法探究砾岩储集层特征及对化学驱油剂损耗的影响

以克拉玛依油田七东1区克下组砾岩储集层为研究对象,通过X射线衍射、薄片鉴定、孔渗分析等实验,系统开展储集层纵向岩石学特征、孔隙结构特征及宏观物性变化的研究。结合驱油剂动态损耗实验,采用基于交叉验证的逐步回归法,探究储集层特征对驱油剂损耗规律的影响;并应用Petrel建模计算油藏范围内驱油剂损耗量。结果表明:研究区储集层矿物成分成熟度低,结构成熟度低,储集层呈现中-低孔隙度,渗透率纵向变化大,非均质性显著;驱油剂动态损耗量受储集层特征控制,与储集层渗透率、孔隙度、黏土矿物含量等地质特征有较好的相关关系;应用Petrel建模可以实现快速、准确、可视化的油藏范围内驱油剂损耗量计算。在地质条件复杂、驱油剂损耗机理未完全探究清楚的情况下,通过逐步回归法直接从数据中建立模型;并用交叉验证法对模型进行筛选和优化,是驱油剂损耗量计算领域的一个创新应用。

Study on Conglomerate Reservoir Characteristics and Their Influences on Oil Displacement Agent Loss Based on Cross Validation

Studying on conglomerate reservoir of Lower Karamay Formation in east district 7(1) of Karamay Oilfield, this paper systemically worked on the vertical distribution of mineralogy, pore structure and other petrophysical properties via X-ray diffraction, thin section analysis, porosity and permeability measurements. Combined with experiments of oil-displacing agents dynamic loss, this paper used stepwise regression method based on cross validation to quantify the influence of reservoir characteristics on oil-displacing agents dynamic loss, and calculated the oil-displacing agents dynamic loss within a reservoir by Petrel modeling. Results show that the conglomerate reservoir is characterized by low compositional maturity and low textural maturity. Medium-low porosity and heterogeneous vertical distributions of permeability are significant in the study area. The oil-displacing agents dynamic losses are controlled by reservoir characteristics. There are strong correlations between oil-displacing agents dynamic losses and permeability, porosity and clay minerals content. This paper also used Petrel model to efficiently and visually predict the oil-displacing agents losses within the whole reservoir. With the complex geological conditions and difficulty that the mechanism of oil displacement agents loss is not completely clear, modeling directly from the data using stepwise regression method, and models selection as well as optimization using cross validation are innovative applications in calculating oil-displacing agents losses.