摘要
通过高压压汞、扫描电镜、铸体薄片、荧光观察、含油饱和度测试等实验方法,并结合分形理论,对延8~延10层位典型样品的孔喉结构及其复杂特征开展定量分析,探讨孔喉结构对含油性的控制作用。研究结果表明,铁边城地区延8~延10储层主要由岩屑砂岩构成,孔隙类型以粒间孔和长石溶孔为主,广泛发育微纳米级孔隙,平均孔隙度为14.54%,平均渗透率为0.24×10^(-3)μm^(2),属于中孔-超低渗储层。低渗储层孔喉结构复杂,多为大孔-细喉的组合,样品储集空间越大,孔喉结构复杂程度越高。孔喉结构具有三段式分形特征,依次对应大、中、小孔喉段,各段平均分形维数分别为2.8535、2.4358、2.4491。大孔喉段虽储集能力高,但并不能决定低渗储层整体的含油饱和度,而中孔喉段对含油饱和度起主导作用。大孔-粗喉组合越发育,中孔喉段分布越均质,越有利于石油在低渗储层中的富集。最有利于油气富集的孔喉半径范围为0.02~1μm。该研究成果为进一步优化铁边城地区的油气开发策略提供了关键的科学依据。
In order to further guide the exploration and development of oil reservoirs in Tiebiancheng area,the pore throat structure and its complex characteristics of typical samples in Yan 8-Yan 10 layers were quantitatively analyzed by using experimental methods such as high-pressure mercury injection,scanning electron microscopy,cast thin section,fluorescence observation,oil saturation test and fractal theory,and the control effect of pore throat structure on oil content was discussed.The results show that the Yan 8-yan 10 reservoirs in Tiebiancheng area is mainly composed of lithic sandstone,and the pore types are mainly intergranular pores and feldspar dissolved pores,with micron sized pores widely developed.The average porosity is 14.54%and the average permeability is 0.24×10^(-3)μm^(2),belonging to medium porosity ultra-low permeability reservoir.The pore throat structure of low permeability reservoir is complex.The larger the sample storage space in this area,the higher the complexity of pore throat structure,which is mostly a combination of large pore and fine throat.The pore throat structure has three fractal segments,which corresponds to the large,medium and small pore throat segments in turn.The average fractal dimensions of each segment are 2.8535,2.4358 and 2.4491,respectively.Although the reservoir capacity of the large pore throat section is high,it does not determine the overall oil saturation of the low-permeability reservoir.The more developed the macropore coarse throat combination,the more homogeneous the distribution of the mesopore throat,which is more conducive to the enrichment of oil in low-permeability reservoirs.The radius range of pore throat which is most conducive to oil and gas enrichment is 0.02~1μm.The research results provide a key scientific basis for further optimizing the oil and gas development strategy in the Tiebiancheng area.
作者
武景岳
屈怡倩
程鑫
左学谦
程钰婷
吴汉宁
孙卫
WU Jingyue;QU Yiqian;CHENG Xin;ZUO Xueqian;CHENG Yuting;WU Hanning;SUN Wei(Department of Geology,Northwest University,Xi’an 710069,China;School of Mechanical Engineering,Hubei University of Technology,Wuhan 430068,China)
出处
《西北大学学报(自然科学版)》
北大核心
2026年第1期187-201,共15页
Journal of Northwest University(Natural Science Edition)
基金
国家自然科学青年基金(42202143)。
关键词
分形维数
孔喉结构
储层含油性
鄂尔多斯盆地
fractal dimension
pore throat structure
reservoir oil saturation
Ordos Basin
