河流相储层精细对比及沉积特征探讨——以惠民凹陷大芦家地区临25-1断块馆二上段为例

以惠民凹陷大芦家临25-1断块馆二上段河流相储层为例,对河流相储层精细对比研究方法以及其沉积特征进行探讨。针对研究区开发中存在的小层对比不清,有利储层分布不明确的问题,以标准层划分层位,以沉积旋回法、河流叠加砂体对比原则划分沉积单元,建立精细小层对比格架;通过观察分析取心井岩石成分、沉积构造等一系列特征,结合测井曲线资料,揭示研究区内小层沉积微相及其展布特征。研究表明,大芦家地区临25-1断块馆二上段小层叠加样式包括间歇叠加、连续叠加、侵蚀叠加三种类型;主要为曲流河沉积,发育点坝、天然堤、决口扇、泛滥平原四种微相;早期主要是河道砂体沉积,点坝砂体连片分布,晚期北部的决口扇沉积发育较明显,二者为研究区的有利储层。

Study on Detailed Contrast and Sedimentary Characteristics of Fluvial Reservoir: By Taking the Upper Part of the Second Member of Guantao Formation in Lin25-1 Fault Block, Dalujia Area, Huimin Depression for Example

Take the Upper Part of the Second Member of Guantao Formation in L25-1 Fault Block, Dalujia Area, Huimin Depression for example, this paper study on detailed contrast and sedimentary characteristics of fluvial reservoir. The layer correlation and favorable reservoir distribution of the study area, are not clear. Herein, based on the standard layer,the study layer is identified. Then comparative framework of small layer is established, according to sedimentary cycle and the principle of comparative about river sand. Based on the analysis of the characteristics of rock components and sedimentary structures about the cores and well logs data, types of sedimentary microfacies and distribution characteristics of microfacies are identified. The results show that: 1) Three types of stacking pattern of small layers contain in L25-1 fault block region, as intermittent superposition, continuous superposition and erosional superposition. 2) Sedimentary face is meandering river, including four types of microface, as point bar, natural levee, crevasse splay and flood plains. 3) Channel deposit is the main type of sedimentary face in early period with a contiguous distribution of point bar sand, due to frequent channel swing, while crevasse splay deposit can be obviously recognised in north of study area in the later period, both are favorable reservoir .