鄂尔多斯盆地吴起油田长6油层组沉积微相特征及其对储层的控制  

Sedimentary Microfacies of Chang 6 Oil-Bearing Formation and Its Control on Reservoir in Wuqi Oilfield,Ordos Basin

作　　者：蒋天昊 宋方新 邓宝康 翟学智 于浩然 李志豪 JIANG Tianhao;SONG Fangxin;DENG Baokang;ZHAI Xuezhi;YU Haoran;LI Zhihao(No.10 Oil Production Plant,Changqing Oilfield Company,Petro China,Qingyang 745100,Gansu,China;Sichuan OGT Technology Development of Oilfield Co.,Ltd.,Chengdu 610041,Sichuan,China)

机构地区：[1]中国石油长庆油田分公司第十采油厂,甘肃庆阳745100 [2]四川奥吉特油田科技开发有限公司,四川成都610041

出　　处：《西北地质》2020年第4期130-139,共10页Northwestern Geology

基　　金：国家科技重大专项“鄂尔多斯盆地大型低渗透岩性地层油气藏开发示范工程”(2016ZX05050)。

摘　　要：重新认识注水开发中后期油藏的沉积微相和砂体展布特征对精准定位剩余油、调整开发井网和提高水驱采收率具有重要意义。在综合运用岩心观察、薄片鉴定和测井分析的基础上,对吴起油田延长组长6油层组的沉积微相进行了精细研究,明确了研究区长6油层组属于三角洲前缘亚相沉积,发育有水下分流河道、分流间湾和河道侧翼3种沉积微相。通过选取10个储层特征参数,对目标区储层进行了分类评价,并绘制出各小层沉积微相平面图和储层分类评价图,定量评价了长6油层组沉积微相对储层的控制作用。结果表明,长6油层组中长61与长62继承性较好,其水下分流河道砂体整体发育程度最好,油气主要赋存于长61和长62的水下分流河道砂体及水下分流河道与河道侧翼的组合砂体之中。长6储层孔隙结构类型可划分为3类,Ⅰ、Ⅱ类储层主要发育在水下分流河道微相上,孔隙结构参数较好中等,是未来挖潜的主要方向。Ⅲ类储层最为致密,孔隙结构参数差,开发价值较低。长61和长62中三类储层发育程度最高,且Ⅰ类和Ⅱ类储层的分布数量和分布规模最大。根据各小层的储层分类评价图,为精准定位剩余油、调整挖潜方案提供了依据。It is of great significance to re-recognize the characteristics of the sedimentary microfacies and sand body distribution in the middle and late stage of waterflood development for accurately locating remaining oil,adjusting development well pattern and improving water drive recovery.The authors studied in details the sedimentary microfacies of Chang 6 reservoir in Wuqi oilfield based on the core observation,thin section identification and well logging analysis.It is made clear that Chang 6 oil-bearing formation in the study area belongs to delta front subfacies and three sedimentary microfacies,namely underwater distributary channel,distributary Bay and channel flank.The authors classified the reservoir in the study area using 10 selected influencing parameters and drew out the plan of sedimentary microfacies and the map of reservoir classification,thus quantitatively evaluated the controlling effect of sedimentary microfacies on the reservoir.The results show that the Chang 6~1 and Chang 6~2 have good inheritance,and the underwater distributary channel of sand body is well developed.The oil and gas are mainly concentrated in the sand body of Chang 6~1 and Chang 6~2 underwater distributary channel and the combined sand body of underwater distributary channel and channel flank.The pore structure types of Chang 6 reservoir can be divided into three types.Type Ⅰ and Ⅱ are mainly developed in the microfacies of underwater distributary channel,the pore structure parameters being preferable to developing in the future.Type Ⅲ is the most compact with poor structure parameters and low development value.The above three types in Chang 6~1 and Chang 6~2 are well-developed,among which type I and type Ⅱ reservoirs are the largest in distribution quantity and scale.The reservoir classification and evaluation map of each small layer provide a basis for accurate positioning of remaining oil and the adjustment of potential exploration plan.

关 键 词：鄂尔多斯盆地 长6油层组 沉积微相 水下分流河道 孔隙结构 

分 类 号：P618.13[天文地球—矿床学]