杏北油田低弯度分流河道储层构型及其控制的剩余油分布模式
Architecture Characteristics of Low Sinuosity Distributary Channel Reservoir and Its Controlling Factors on Residual Oil Distribution： A Case Study of Xingbei Oilfield, China

摘要： 低弯度分流河道储层是杏北油田的重要储层类型，深入研究其储层构型特征对于油田调整挖潜意义重大。综合密井网岩心、测井和生产动态等资料，采用“层次分析和模式指导”的方法，分“复合河道和溢岸砂体、单期河道及其相互接触关系”两个主要层次开展储层构型精细解剖，构建了三维储层构型模型。基于密闭取心井、水淹层测井解释资料和生产动态数据分析了不同时期的水淹特征和剩余油分布，并通过基于三维构型模型的油藏数值模拟对剩余油分布模式进行验证，最终总结出不同储层构型控制下的剩余油富集模式。结果表明，在河道内，剩余油在顶部、边部、河道间夹层控制部位以下以及仅与低渗溢岸砂连通造成注采不完善的河道内部富集；在河道外，剩余油在河间物性较差的溢岸砂内、注采不完善的溢岸砂末端和孤立砂体内富集。
Abstract: Lowsinuosity distributary channel reservoir is an important reservoir type of Xingbei oilfield and it is of great significance to further study its reservoir architecture characteristics for the adjustment and potential tapping. Based on the data of cores, wireline logs and production performance from close wellspacing block, the reservoir architecture of low sinuosity distributary channel in Xingbei oilfield was finely analyzed by using “hierarchy analysis and depositional pattern guidance” with two primary hierarchies which were the determination of amalgamated channels and overbank sandstone bodies and the contact relationships among solitary channels. The 3D reservoir architecture model was then established. Based on the static data of sealed coring wells and watercut welllogging interpretation results and the production performance data, the waterflooding features of different periods and distribution of remaining oil were analyzed. Subsequently, the distribution of remaining oil was verified by numerical reservoir simulation based on 3D reservoir architecture model. Finally, the distribution of remaining oil controlled by the reservoir architecture was summarized and demonstrated as follows: within the channel, the remaining oil volumes are enriched in the top and edge of the channel, the lower areas controlled by mud or calcareous interbeds between individual channels and undeveloped areas just connecting with lowpermeability overbank sands. Outside the channel, they are mainly in lowpermeability overbank sands, end of the overbank sands and the isolated sandstone bodies with imperfect injectionproduction systems