摘要
砂岩的孔隙微观结构决定着储层的渗流能力,极大程度影响油气产能及其分布,是当前油气储层的研究重心.以郝滩地区延安组下段延8—延10储集砂岩为研究对象,通过铸体薄片、扫描电镜及高压压汞等实验数据,对其孔隙结构特征进行定性和定量表征,并结合成岩序列讨论其孔隙演化过程.研究表明:郝滩地区延安组延8—延10储集砂岩主要发育残余粒间孔和长石溶孔发育,多见大-中孔、中-小喉道型孔隙结构,整体表现中孔、中低渗储层特征.强压实作用和强胶结作用是储集砂岩致密化的主要因素,分别致使孔隙度下降了13.81%~14.28%和1.14%~3.18%;铁方解石的胶结作用和交代作用、绿泥石薄膜保护残余粒间孔以及溶蚀作用形成的次生溶孔是主要的致密油储集空间,溶蚀作用使孔隙度平均增加了1.34%~3.84%.
The pore microstructure of tight sandstone reservoirs is crucial in determining their seepage capacity,significantly impacting oil and gas production and distribution,and is a primary research focus in oil and gas reservoir studies.Using the Yan 8 to Yan 10 storage sandstone in the Haotan region,this study characterizes the pore structure of the storage sandstone through experimental data from casting sheets,scanning electron microscopy,and high-pressure mercury intrusion.The pore evolution process is also discussed concerning the diagenetic sequence.The study reveals that the high-quality reservoir lithology in the Yan 8 to Yan 10 reservoirs predominantly features intergranular and feldspathic pores,with a pore structure mainly comprising large to medium pores and medium to small throat-like pores.These reservoirs exhibit mid-range porosity and medium to low permeability characteristics.Compaction and cementation are identified as the primary factors for reservoir densification,leading to porosity decreases of 13.81%-14.28%and 1.14%-3.18%,respectively.The residual interpore,preserved by cementation involving iron calcite and chlorite films,along with secondary dissolution pores formed by dissolution processes,constitute the main storage spaces for tight oil.Dissolution processes increased the porosity by an average of 1.34%-3.84%.
作者
汪洋
黄延明
张希
胡晓雪
葛政廷
肖飞
吴雨风
WANG Yang;HUANG Yanming;ZHANG Xi;HU Xiaoxue;GE Zhengting;XIAO Fei;WU Yufeng(No.6 Oil Production Plant of Changqing Oilfield Company,Xi’an 710200,China;Oilfield Development Division of Changqing Oilfield Company,Xi’an 710000,China;School of Earth Science and Resources,Chang’an University,Xi’an 710054,China)
出处
《河南科学》
2024年第1期79-88,共10页
Henan Science
基金
国家自然科学青年基金资助项目(41502137)。
关键词
郝滩新区
延安组
孔隙演化
成岩作用
成岩序列
Haotan area
Yan’an Formation
pore evolution
diagenesis
diagenetic order
