延安气田延长东地区盒8段致密气藏储层特征研究  

Study on reservoir characteristics of He8 tight gas reservoir in Yanchang east area of Yan’an Gasfield

作　　者：李成 魏虎[1] 吴金桥[1] 李涛 杜锦 郭雨嘉 高泽 王波 LI Cheng;WEI Hu;WU Jinqiao;LI Tao;DU Jin;GUO Yujia;GAO Ze;WANG Bo(Natural Gas Research Institute of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,Xi’an 710065,China)

机构地区：[1]陕西延长石油(集团)有限责任公司天然气研究院,西安710065

出　　处：《非常规油气》2024年第4期49-61,共13页Unconventional Oil & Gas

基　　金：国家科技重大专项“陆相页岩气水平井高效低成本钻完井技术”(2017ZX05039003);延长石油科研项目“延长东致密气藏水平井开发技术优化研究”(ycsy2022jctsB23)。

摘　　要：为深化延安气田延长东地区致密气藏地质认识,对研究区盒8段储层开展了岩石学、物性和孔隙结构特征研究,并对物性主控因素进行了分析。结果表明:1)砂岩类型以岩屑石英砂岩为主,碎屑组分以石英为主,黏土矿物以绿泥石和伊利石为主,脆性指数和成分成熟度较高,孔渗呈强指数正相关和不对称双峰状分布,平均孔隙度为5.3%,平均渗透率为0.101×10^(-3)μm^(2),有效物性下限孔隙度为2.3%、下限渗透率为0.035×10^(-3)μm^(2),渗透率主要受宏孔隙控制;2)平均喉道半径为0.41μm,平均孔隙半径为135.38μm,原生孔隙空间损失较大,孔隙半径、有效孔隙体积和孔喉比为储集空间的主控因素,有效喉道体积为渗流能力的主控因素,储层孔隙结构分为Ⅰ类优质储层、Ⅱ类一般储层和Ⅲ类较差储层;3)储层物性主要受强压实作用、弱胶结作用和弱溶蚀作用控制,初始孔隙度为36.81%,视压实率为71.83%,压实作用减孔量为26.44%,视胶结率为24.50%,胶结作用减孔量为9.02%,视溶蚀率为9.48%,溶蚀作用增孔量为3.49%。该研究成果可为研究区乃至延安气田致密气藏高效勘探开发提供一定的地质依据。In order to deepen the geological understanding of the tight gas reservoir in Yanchang East Area,Yan’an Gas field,the petrology,physical properties and pore structure characteristics of the He8 reservoir in the study area were studied,and the main controlling factors of physical properties were analyzed.The results show that:1)The type of sandstone is mainly lithic quartz sandstone,the clastic component is mainly quartz,and the clay minerals are mainly chlorite and illite.The brittleness index and composition maturity are higher,the porosity and permeability show a strong exponential positive correlation and asymmetric bimodal distribution,and the permeability was mainly controlled by macro pores.The mean porosity and permeability were 5.3%and 0.101×10^(-3)μm^(2) respectively,and the lower limit of effective physical property was 2.3%porosity and 0.035×10^(-3)μm^(2) permeability,the permeability was mainly controlled by macro pores.2)The average throat radius was 0.41μm,and the average pore radius was 135.38μm.The loss of primary pore space is large,and pore radius,effective pore volume and pore-throat ratio are the main controlling factors of reservoir space,and effective throat volume was the main controlling factor of seepage capacity.The pore structure of reservoir can be divided intoⅠhigh quality reservoir,Ⅱgeneral reservoir andⅢpoor reservoir.3)Reservoir physical properties were mainly controlled by strong compaction,weak cementation and weak dissolution.The initial porosity is 38.61%,the apparent compaction rate is 71.83%,the porosity reduced by compaction is 26.44%,the apparent cementation rate is 24.50%,the porosity reduced by cementation is 9.02%,the apparent dissolution rate is 9.48%,and the porosity increased by dissolution is 3.49%.The research results can provide some geological basis for efficient exploration and development of tight gas reservoirs in the study area and even Yan’an Gasfield.

关 键 词：储层特征 盒8段 致密气藏 延安气田 鄂尔多斯盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]