1.Xi'2.'3.an Shiyou University
National Science and Technology Major Special Projects(2016ZX05056-005);Xi'an University of Petroleum Postgraduate Innovation and Practical Skills Training Programme(YCS21112044)
储层孔隙结构对油气勘探开发至关重要，但孔隙几何形状、尺寸分布以及孔隙空间展布等特征难以利用单一手段进行描述。通过岩心资料、铸体薄片资料、扫描电镜资料分析、高压压汞及分形理论等多种方法对鄂尔多斯盆地城华地区长4+5储层微观孔隙结构进行精细表征。研究结果显示:城华地区长4+5储层孔隙度平均为9.93%，渗透率为0.41 mD,表现出典型的特低孔超低渗特征，储层孔喉结构复杂，储层非均质性强。储层中孔隙类型主要为粒间孔、粒内溶孔以及晶间孔和微裂缝；储层孔喉半径主要分布在0.06 μm-2 um；根据压汞曲线将研究区储层孔隙结构分为3类。汞饱和度法研究砂岩储层分形特征表明相对小孔呈现出较好的分形特征，分形维数平均值为2.31，相对大孔分形维数平均值为4.90，表明相对大孔不具分形特征，孔隙结构复杂，非均质性强；分析认为成岩作用、裂缝发育以及过度简化孔隙形态是导致研究区相对大孔分形维数偏大的主要原因。通过计算出的转折点半径与渗透率、中值半径有良好的相关性，表明转折点半径适用于表征孔隙结构非均质性。研究成果对科学勘探开发研究区油气资源具有借鉴意义。
Reservoir pore structure is crucial to oil and gas exploration and development, but the characteristics of pore geometry, size distribution, and pore space distribution are difficult to describe with a single method. The microscopic pore structure of the Long 4+5 reservoir in the Chenghua area of the Ordos Basin was finely characterized by various methods, including core data, cast thin section data, SEM data analysis, high pressure mercury pressure and fractal theory. The research results show that the Chang 4+5 reservoir in Chenghua area has an average porosity of 9.93% and a permeability of 0.41 mD, showing typical extra-low porosity and ultra-low permeability, complex pore throat structure, and strong inhomogeneity of the reservoir. The pore types in the reservoir are mainly intergranular pores, intra-grain solution pores, intergranular pores and microfractures; the pore throat radius of the reservoir is mainly distributed in the range of 0.06 μm-2 um; the pore structure of the reservoir in the study area is divided into three categories according to the mercury pressure curve. The study of the fractal characteristics of sandstone reservoirs by the mercury saturation method shows that the relatively small pores show good fractal characteristics with a mean fractal dimension of 2.31, while the mean fractal dimension of the relatively large pores is 4.90, indicating that the relatively large pores do not have fractal characteristics and have a complex pore structure with strong heterogeneity; the analysis suggests that diagenesis, fracture development and oversimplified pore morphology are the main reasons for the large fractal dimension of the relatively large pores in the study area The analysis suggests that diagenesis, fracture development and over-simplification of pore morphology are the main reasons for the large relative macropore fractal dimension in the study area. The calculated turning point radius has a good correlation with permeability and median radius, indicating that the turning point radius is suitable for characterizing the heterogeneity of pore structure, The results of the study have implications for the scientific exploration and development of hydrocarbon resources in the study area.
陈曦,肖玲. 鄂尔多斯盆地城华地区长4+5段储层孔隙结构及分形特征研究[J]. 科学技术与工程, , ():复制