东海地区低渗-致密储层含水饱和度定量评价方法  

Quantitative evaluation method for water saturation of low permeability-tight reservoirs in East China Sea

作　　者：刘建新 胡文亮 高楚桥[2] 赵彬[2] 付焱鑫 罗健 何玉春 魏晓晗 LIU Jianxin;HU Wenliang;GAO Chuqiao;ZHAO Bin;FU Yanxin;LUO Jian;HE Yuchun;WEI Xiaohan(CNOOC China Limited,Shanghai Branch,Shanghai 200335,China;School of Geophysics & Oil Resources,Yangtze University,Wuhan, Hubei 430100,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335 [2]长江大学地球物理与石油资源学院,湖北武汉430100

出　　处：《中国海上油气》2019年第3期108-116,共9页China Offshore Oil and Gas

基　　金：“十三五”国家科技重大专项“低渗-致密气层测井识别及综合评价技术(编号:2016ZX05027-002-002)”部分研究成果

摘　　要：东海地区低渗-致密储层的岩性及孔隙结构复杂、物性非均质性强,储层含水饱和度的准确计算一直是该类储层测井评价中的难点。提出了2种储层含水饱和度计算方法。一是基于岩心三维纳米CT扫描实验的变m值计算方法,根据数字岩心样品连通孔隙度与胶结指数m理论值,回归拟合出随孔隙度变化的变m值计算公式,建立数字岩心变m值西门度模型求取储层含水饱和度;二是利用核磁测井资料或RC50与渗透率的相关关系式得到RC50的值,进而通过地层因素F与RC50的负相关关系及地层因素F与储层含水饱和度的关系式求取储层含水饱和度。以东海地区X凹陷Y区低渗-致密砂岩储层实际井为例,分析了本文提出的2种模型和定m值西门度模型的计算结果,结果表明本文提出的2种模型的计算结果与密闭取心饱和度更加匹配,说明本文模型更加适用于东海地区低渗-致密储层。Because of the complex lithology and pore structure,and strong heterogeneous of low permeability and tight reservoirs in East China Sea,the accurate calculation of reservoir water saturation has always been a difficulty in the logging evaluation of such reservoirs. In this paper,two methods were proposed for the water saturation calculation of such reservoirs. The first one is the variable m -value calculation method based on the core three-dimensional nano-CT scanning experiment. According to the theoretical values of the connected porosity and the cementation index m of the digital core sample,the calculating formula of variable m value varying with porosity can be obtained through regression fitting,and the Simandoux model of variable m value was established for digital core to obtain the reservoir water saturation. The second one is to use the nuclear magnetic logging data or the correlation between RC 50 and permeability to obtain the value of RC 50 ,and then it is able to obtain the reservoir water saturation through the negative correlation between the stratum factor F and RC 50 ,as well as the correlation between the stratum factor F and reservoir water saturation. By taking the actual wells in the low permeability-tight sandstone reservoirs of Y area of X sag in East China Sea as an example,the calculation results of those two models and that of the fixed m -value Simandoux model have been analyzed. The results show that the calculation results of those two models are better matched with the saturation of sealed coring,indicating that models proposed in this paper are more suitable for the low permeability-tight reservoirs in East China Sea.

关 键 词：东海 低渗-致密储层 含水饱和度 数字岩心变m值西门度模型 F-RC50饱和度模型 

分 类 号：TE122.23[石油与天然气工程—油气勘探]