油气地质与采收率2025，Vol.32Issue(5)：69-80,12.DOI:10.13673/j.pgre.202402009
川中广安须四段低孔渗砂岩有效储层物性下限厘定
Lower limit determination of effective reservoir physical properties of Xu4 Member sandstones with low porosity and permeability in Guang'an area,central Sichuan
摘要
Abstract
The 4th Member of Xujiahe Formation(Xu4 Member)in Guang'an area of central Sichuan has favorable conditions for natural gas accumulation and broad prospects for exploration and development.However,the reservoir exhibits poor physical properties,characterized by high water saturation and challenging reserves production.The gas reservoir is currently in the early stags of exploration and development.Clarifying the lower limit of reservoir physical properties is essential to understanding the sweet spot characteristics and its genesis,as well as comprehensively evaluating gas reservoirs.Therefore,this study utilized experimental analysis and production test data from Xu4 Member reservoir in Guang'an area.Three methods were employed:porosity-permeability statistical analysis,minimum flow pore-throat radius method,and seven submethods of empirical statistical method,porosity-permeability intersection method,water film thickness method,mercury injection parameter method,J function method,production test method,and distribution function curve method were used to ascertain the lower limits of porosities and permeability of the reservoir respectively.In order to avoid the large deviation caused by a single method,the arithmetic mean values of the results obtained by each method were used as the final lower limit values of the physical properties of Xu4 Member sandstone reservoir in Guang'an area.The results indicated that Xu4 Member reservoir in Guang'an area primarily consists of medium-fine-grained feldspathic lithic sandstone,exhibiting a moderate to high level of compositional maturity and a high level of structural maturity as a whole.The average porosity of the reservoir is 5.98%,while the average permeability is 0.86×10-3 μm2.Overall,this reservoir is a tight reservoir with low porosity and permeability.It has high water saturation,averaging 65.17%,and strong heterogeneity.The lower limits of porosity determined by the seven submethods are 3.2%,6.5%,6.1%,6.5%,8.1%,3.2%,and 9.5%,respectively,and those of permeability are 0.193×10-3,0.189×10-3,0.055×10-3,0.163×10-3,0.089×10-3,0.123×10-3,and 0.211×10-3 μm2,respectively.By calculating the arithmetic mean value,the final lower limits of porosities and permeability of Xu4 member reservoir in Guang'an area are 6.2%and 0.146×10-3 μm2,respectively.关键词
须四段/低孔渗砂岩储层/储层特征/物性下限/川中广安Key words
Xu4 Member/sandstone reservoir with low porosity and permeability/reservoir characteristics/lower limit of physical property/Guang'an area of central Sichuan分类
能源科技引用本文复制引用
彭秋,许楚昊,罗弘,车国琼,李顺,高崇龙,杨建东,纪友亮,马梓珂,董志武,刘博文..川中广安须四段低孔渗砂岩有效储层物性下限厘定[J].油气地质与采收率,2025,32(5):69-80,12.基金项目
新疆维吾尔自治区自然科学基金项目"干旱区山前阵发性河流体系沉积及地貌差异演化机制研究"(2022D01B41),克拉玛依市创新人才专项"准南前陆冲断带深层储层非均质性演化重建及油气差异聚集模式研究"(2024hjcxrc0076),中国石油大学(北京)克拉玛依校区科研启动基金"前陆冲断带深层高效储层油气差异聚集机制研究"(XQZX20230010). （2022D01B41）
