低渗及致密砂岩含油程度动态评价方法研究——以鄂尔多斯盆地南部地区延长组为例  

Research on the dynamic evaluation method for oil-bearing degree of low-permeability and tight sandstone reservoirs:a case from the Yanchang formation of south Ordos basin

作　　者：夏鲁[1,2] 刘震[1,2] 刘静静[1,2] 卢朝进 李廷安 孙迪[1,2] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]中国石油大学地球科学学院,北京102249

出　　处：《中国矿业大学学报》2016年第6期1193-1203,共11页Journal of China University of Mining & Technology

基　　金：中国石油"十二五"油气重大专项项目(2011ZX05001)

摘　　要：针对静态储层评价方法不能很好地解释和预测低渗及致密砂岩的含油气性、动态储层评价方案无法对储层含油程度进行科学预测的情况,本文以鄂尔多斯盆地镇泾—西峰地区长6-长8段低渗及致密砂岩储层为对象,采用减孔过程和增孔效应相互叠加的方法恢复成藏期古孔隙度,并分析试油资料中的关键参数与储层孔隙度之间的各种关系,提出利用成藏期孔隙度（Φ成藏期）与临界孔隙度（Φ临界）的差值评价储层含油程度的新方法.研究结果表明：成藏期的储层临界孔隙度可作为评价储层有效性的关键指标,而储层物性与临界充注动力之间的耦合关系可用来判别有效储层的含油气性,在此基础上依据砂岩孔隙度与含油程度的关系可确立储层含油等级.用该方法可将该区砂岩储层划分为低含油差储层（Ⅲ类）、中等含油储层（Ⅱ类）、高含油好储层（Ⅰ类）3类,Φ_（成藏期）与Φ_（临界）的差值依次为：〈3%,3%～6%和〉6%;试油产油率分别为：0～20%,20%～70%和70%～100%.该评价方法的科学性、有效性在安塞地区得到验证,比以往评价方法更适合于评价低渗及致密砂岩储层的含油程度.The static methods of reservoir evaluation is limited in interpreting and predicting the oil-bearing properties of low-permeability and tight sandstone reservoirs,while the dynamic reservoir evaluation is still unable to scientifically predict the oil-bearing degree of reservoirs.Based on the paleoporosity recovery model that combined porosity decreasing process and porosity increasing effect,this paper focused on the low-permeability and tight sandstone reservoirs in Chang 6to 8members of Yanchang formation in Zhenjing-Xifeng areas of Ordos basin and rebuilt the paleoporosity at hydrocarbon accumulation period.Subsequently,the variety relationships between reservoir porosity and key parameters in oil production test data were analyzed.Finally,a new evaluation method by the difference between porosity at accumulation period and critical porosity was proposed to evaluate oil-bearing degree of reservoirs.The re-sults show that the reservoir critical porosity at accumulation period can be taken as a key parameter for reservoir effectiveness evaluation,and the coupling relationship between reservoir physical properties and critical charging pressure can be used as a judging criterion for the oilbearing properties of effective reservoirs.On this basis,the evaluation method for oil-bearing ranks of low-permeability and tight sandstone reservoirs can be established through the relationship between sandstone porosity and oil-bearing degree.According to this evaluation method,the sandstone reservoirs in the study area were divided into three types：low oil-bearing reservoir（Class Ⅲ）,moderate oil-bearing reservoir（ClassⅡ）and high oil-bearing reservoir（ClassⅠ）,whose differences between porosity at accumulation period and critical porosity are3%,3%—6%,and 6%,with oil production rates of 0—20%,20%—70%,and 70%—100%,respectively.The new evaluation method is further verified by the sandstone reservoirs in Ansai area,and found to be more suitable and reasonable for the oil-bearing degree evaluation of l

关 键 词：低渗及致密砂岩储层 动态储层评价 成藏期孔隙度 临界孔隙度 试油产油率 

分 类 号：TE122[石油与天然气工程—油气勘探]