辽中凹陷南洼中深层储层孔隙度分布特征及影响因素分析  

Analysis of porosity distribution characteristics and influencing factorsof middle-deep reservoirs in the southern subsag of Liaozhong Sag

作　　者：王茂桢 王冰洁 郝轶伟 徐坤明 WANG Maozhen;WANG Bingjie;HAO Yiwei;XU Kunming(Tianjin Branch,CNOOC Limited(China),Tianjin 300459)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《长江大学学报（自然科学版）》2023年第3期23-32,共10页Journal of Yangtze University(Natural Science Edition)

基　　金：国家科技重大专项“渤海海域勘探新领域及关键技术研究”(2016ZX05024-003);中海石油(中国)有限公司“七年行动计划”重大科技专项课题“渤海油田上产4000万吨新领域勘探关键技术”(CNOOC-KJ 135 ZDXM 36 TJ 08 TJ)。

摘　　要：勘探实践表明渤海湾盆地辽中凹陷南洼中深层(埋深大于2500 m)东营组和沙河街组储层孔隙度分布特征复杂,其孔隙度演化机制亟待明晰。为了定量表征其中深层储层孔隙度的分布特征并分析其影响因素,以辽中凹陷南洼旅大16~21构造带古近系储层为研究对象,利用数值模拟的方法,基于Athy’s Law机械压实模型计算了中深层砂岩储层的标准孔隙度,将实测孔隙度值和理论标准值进行对比,定量分析孔隙度的变化程度,并对引起孔隙度变化的主控因素进行了分析。结果表明:旅大16-3南构造东营组三段压实作用控制孔隙度演化,旅大16-3北构造沙河街组二段异常高含量的碳酸盐胶结物使孔隙度显著减小,减小幅度在13%~18%的范围内,旅大21-1构造发育的欠压实超压作用对沙河街组四段砂岩储层孔隙度具有一定程度的保护作用,保存的孔隙度可以达到7%。Exploration practice shows that the reservoir porosity distribution characteristics of Dongying and Shahejie Formations in the middle-deep layers(buried depth greater than 2500 m)of southern subsag of Liaozhong Sag in Bohai Bay Basin are complex,and their porosity evolution mechanism needs to be clarified urgently.In this paper,in order to characterize the distribution characteristics of deep reservoir porosity quantitatively and analyze their influencing factors,taking the Paleogene reservoir in the LD 16~21 structural belt of the southern subsag of Liaozhong Sag as the research object,the standard porosity of middle-deep sandstone reservoirs was calculated by numerical simulation method based on Athy’s Law mechanical compaction model,and the measured porosity value was compared with the theoretical standard value.The degree of porosity change was quantitatively analyzed,and the main controlling factors causing the porosity changes were analyzed.The results show that the compaction of the third member of Dongying Formation in the southern structure of LD 16-3 controls the evolution of porosity.In second member of Shahejie Formation in the northern structure of LD 16-3,the abnormally high content of carbonate cements causes a strong decrease of porosity,with a decreasing range of 13%to 18%.The undercompaction and overpressure developed in the LD 21-1 structure have a certain degree of protection on the porosity of the sandstone reservoirs in the fourth member of the Shahejie Formation,and the preserved porosity can reach 7%.

关 键 词：孔隙度分布 中深层储层 碳酸盐含量 超压 孔隙度演化 

分 类 号：TE122.23[石油与天然气工程—油气勘探] P618.130.21[天文地球—矿床学]