Albert湖盆北区退积型浅水三角洲沉积及储层特征

Retrogradation shallow water delta sedimentary model and reservoir characteristics in north area of Albert lacustrine basin

根据古生物、岩心、测井、地震等资料,采用储层沉积学、古生物学、地震地层学及类比等方法,从区域构造-沉积演化特征入手,建立了东非裂谷西支北端Albert湖盆北区退积型浅水三角洲沉积模式,系统剖析了沉积体系与砂体展布特征,分析了储层相带物性差异及其影响因素。Albert湖盆北区上上新统目的层段自下向上依次发育三角洲平原、三角洲前缘及前三角洲亚相,其中三角洲平原分流河道为主要储层砂体,储集物性好,而前缘砂体较薄,平面上分布局限,储集物性相对较差。研究成果为该地区油藏储层精细描述及开发方案编制提供了地质依据。

According to paleontology, cores, well logging, seismic data and so on, using reservoir sedimen- tology, paleontology, seismic stratigraphy and analogy methods, retrogradation shallow water delta depo- sitional model in north area of Albert lacustrine basin, in the north of west branch of the East African Rift was established based on characteristics of regional tectonic-sedimentary evolution. The sedimentary sys- tem and sand distribution characteristics were systematically analyzed and the difference of reservoir prop- erties in the sedimentary facies belt and the influencing factors were analyzed. In the north area of Albert lacustrine basin, the objective target successively develops delta plain, delta front and prodelta from bot- tom to up for Upper Pliocene where distributary channel in delta plain is the main reservoir sand body with good property, and sand body in delta front is thinner with restricted distribution on plane and relatively poor property. Research results can provide geological basis for reservoir fine characterization and develop- ment plan programming in this area.