摘要
致密油储层孔喉结构复杂,非均质性强,现有的单一实验技术无法将其全孔径进行有效表征。在分析目前表征方法的基础上,通过铸体薄片、扫描电子显微镜、高压压汞及恒速压汞等实验,综合研究了陕北定边地区延长组长7段致密油储层孔隙结构特征,通过联合压汞法,探讨了致密油联通孔隙的孔径大小及分布特征,细分了孔喉类型。结果表明,高压压汞表征的孔喉半径分布在0.0036~40μm,大于1μm的样品占比约12.5%;恒速压汞表征的孔隙半径分布在80~300μm,喉道半径分布范围为0.12~10μm。全孔径曲线表征孔径分布在0.0036~300μm,二者重叠区域分布在0.12~40μm,结合全孔径分布频率,探索性的将定边地区长7段的储集空间孔喉类型划分为8个区域,最终认为研究区目的层多集中发育中孔、大孔、纳米级孔喉及微—细喉道。这将为致密油储层孔喉大小及储集空间研究提供一种新思路和新手段,意义深远。
None of the existing single experimental methods can effectively characterize its full aperture,because tight oil reservoir has complex pore throat structure and strong heterogeneity.Based on the analysis of current characterization methods,the pore structure characteristics of Yanchangzu Chang 7 tight oil reservoir in Dingbian area of Shanbei are studied by casting thin sections,scanning electron microscopy,high pressure mercury injection and constant speed mercury injection,and so on.The pore size and distribution characteristics of the connected pores in tight oil were discussed by combined mercury injection method,and pore throat types were subdivided.It turns out,the pore-throat radii characterized by high-pressure mercury injection ranged from 0.0036μm to 40μm,samples that larger than 0.1μm accounted for about 25%.The pore radius of mercury injection is 80~300μm,the laryngeal radius ranged from 0.12 to 10μm,the overlapped region is 0.12 to 40μm.The full-aperture curve shows that the pore size distribution ranges from 0.0036μm to 300μm,the overlapped region of the two methods ranges from 0.12 to 40μm,combined with the full aperture distribution frequency,the reservoir space types of Yanchangzu Chang 7 in Dingbian area are tentatively divided into eight regions.Finally,it is concluded that the target layers in the study area mainly develop medium and large pores,nano-scale pores and micro-fine throats,which will provide a new idea and new means for the study of pore throat size and reservoir space of tight oil reservoir,which has far-reaching significance.
作者
吴春燕
展转盈
李文厚
王宁
吴琳
Wu Chunyan;Zhan Zhuanying;Li Wenhou;Wang Ning;Wu Lin(Research Institute of Yanchang Petroleum(Group)Co.,Ltd.,Shaanxi Provincial Key Laboratory of Continental Shale Gas Accumulation and Development,Xi'an 710065;School of Chemical Engineering,Xi'an Shiyou University,Xi'an 710065;Department of Geology,Stake Key Laboratory of Continental Dynamic,Northwest University,Xi'an 710069)
出处
《地质科学》
CAS
CSCD
北大核心
2023年第2期710-722,共13页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家自然科学基金青年项目(编号:41702117,41802187)
国家自然科学基金重点项目(编号:41330315)资助。
关键词
压汞法
致密油储层
孔喉特征
长7段
定边地区
Mercury injection method
Tight oil reservoir
Pore-throat characteristics
Chang 7 member
Dingbian area
