吴起油田曾岔区块28-57井区长6油层组砂体分布及沉积环境约束

Distribution of Sand Bodies and Constraint of Depositional Environment in Chang 6 Reservoir in Wellblock 28-57 of Zengcha Area in Wuqi Oilfield

摘要: 综合岩心、测井等资料，在典型沉积相标志研究的基础上认为，曾岔区块28-57井区长6油层组为三角洲前缘亚相，主要包括水下分流河道、河口沙坝、分流间湾和水下天然堤4种微相。分析了各个小层砂体展布及沉积微相的平面展布规律，探讨了沉积微相对储层砂体的控制作用。结果表明，长6油层组砂体主要为水下分流河道与河口坝，总体上除长6₃²和长6₁¹小层沉积期，其他各小层砂体均较为发育，平面上呈北东南西向连片分布，垂向上相互叠置。

Abstract: Based on the comprehensive analysis of cores and well logging data, and the study of typical sign of sedimentary facies, Chang 6 Reservoir in Wellblock 28-57 of Zengcha Block belonged to a delta front subfacies, mainly including four microfacies such as underwater distributary channel, mouth bar, distributary bay and natural levee. The distribution of sand bodies and the distribution of sedimentary microfacies were analyzed. The controlling effect of sedimentary microfacies on sand body was discussed. The results show that the sand bodies in Chang 6 Reservoir are mainly underwater distributary channel and mouth bar. On the whole, in addition to the sedimentary stages of Chang 632 and Chang 611, sand bodies in the other sublayers are more developed. In the plane, they are distributed continuously in NESW direction, and superimposed each other vertically.