姬塬地区长2 1油层组沉积相研究

Study on Sedimentary Facies of Chang 2_1 Oil-bearing Fomation in Jiyuan District

根据大量的岩芯观察及测井曲线分析,认为姬塬地区长21油层组主要为湖泊三角洲前缘亚相。根据沉积层序特征,可将该区三角洲前缘亚相划分为水下分流河道、水下天然堤、水下决口扇、河口砂坝、席状砂以及水下分流间湾等六种沉积微相。其中水下分流河道微相和河口砂坝微相是该区长21的有利储层,水下分流河道砂体和河口坝砂体是该区今后勘探的方向。沉积相分析师研究砂体分布的关键技术,沉积相确定的正确与否直接影响着对砂体分布规律的认识。

According to analysis of core samples and logging data,it is indicated that front-delta deposition is the main sedimentary system of Chang 21 oil-bearing fomation in Jiyuan district.It includes six types of sedimentary microfacies which are the distributary channel deposits,underwater natural levee,underwater crevasse splay,river mouth bar,sheet sand and the inter-distributary channel deposits.The distributary channel deposits and river mouth bar are the good reservoirs,and also are the direction of developing in this area.The sedimentary facies analysis is the key to study the sand body distributes,determining sedimentary facies correctly or not is affecting directly to understanding sand distribution rule.