大宁-吉县地区山西段致密气储层孔隙结构分形特征及分级评价
Fractal Characteristics Andhierarchical Evaluation of the Tight Gas Reservoir'S Pore Structure in Shanxi Formation of Daning-Jixian Area
孙和美 1刘之的 1邢雪杰 2刘琦 2邓琳 2张正朝 2杨宏涛 2张雷曌1
作者信息
- 1. 西安石油大学地球科学与工程学院,西安 710065;西安石油大学陕西省油气成藏地质学重点实验室,西安 710065
- 2. 中石油煤层气有限公司,西安 715400
- 折叠
摘要
基于铸体薄片、场发射扫描电子显微镜、物性、核磁共振和高压压汞等实验测试资料,利用分形几何原理和方法,对鄂尔多斯盆地大宁-吉县区块山西段致密砂岩储层的孔隙结构进行分形维数计算,并研究其与储层物性、孔隙结构等参数的相关性,以进一步对致密储层孔隙结构进行分级评价研究.研究表明:山西段平均孔隙度、渗透率为5.05％、0.15mD,储集空间的类型主要有粒间溶孔、晶间溶孔以及剩余粒间孔.汞饱和度法计算的分形维数与孔渗、孔隙结构参数之间相关性较好,其范围在2.11至2.87之间,平均值为2.5.通过汞饱和度法将储层孔隙结构分为三类:Ⅰ类、Ⅱ类、Ⅲ类.研究区的孔隙结构类型主要为Ⅱ、Ⅲ类.通过孔隙结构分级评价定量反映致密砂岩储层微观非均质性的复杂程度,为有利储层、致密气的规模勘探开发提供有效地质依据.
Abstract
The fractal dimension of the pore structure of the tight sandstone reservoir in the Daning-Jixian block of the Ordos Basin's Shanxi formation was calculated using the ideas and techniques of fractal geometry,and its relationship to the reservoir's physical characteristics,pore structure,and other factors was examined based on the experimental data of cast thin sections,field emission scanning electron microscopy,physical properties,high-pressure mercury injection,nuclear magnetic resonance,etc.The tight reservoir's pore structure was then further investigated using a hierarchical evaluation.Based on the findings,it was discovered that the Shanxi formation has an average porosity and permeability of 5.05％and 0.15 mD,respectively,which shows that the reservoir space predominantly consists of intergranular dissolved holes,intercrystalline pores,and residual intergranular pores.With values ranging from 2.11 to 2.87 and an average of 2.5,the porosity,permeability,and pore structure characteristics show a good association with the fractal dimension determined using the mercury saturation technique.The reservoir's pore structure may be divided into Type Ⅰ,Type Ⅱ,and Type Ⅲ using the mercury saturation method.Type Ⅱ and Type Ⅲ pore structure types predominate in the Daning-Jixian block.The complexity of micro-heterogeneity of tight sandstone reservoirs is quantitatively reflected through the evaluation of pore structure classification,which provides an effective geological basis for searching for favorable reservoirs and large-scale exploration and development of tight gas.
关键词
孔隙结构/分形特征/致密储层/汞饱和度法/高压压汞Key words
pore structure/fractal characteristic/tight sandstone reservoir/mercury saturation method/high-pressure mercury injection引用本文复制引用
出版年
2024
NETL
NSTL
万方数据