辽河西部凹陷东侧冷35井区沙三段储层特征研究

Research on reservoirs characteristics of Member 3 of Shahejie Formation in the area of Leng35 weliblock,West Depression of Liaohe basin

利用岩心观测、铸体薄片、X—衍射、物性分析、压汞分析等方法,总结研究了冷35井区沙三段储层特征及影响因素。结果表明,沙三时期该区的沉积环境为半潮湿、半干旱较温凉的古气候条件下的陆相湖泊沉积环境。储集层发育水下重力流砂体和湖底扇砂体两种类型,储集岩主要属岩屑质长石砂岩与混合砂岩;储层孔隙不发育、分布不均匀,以微细、极细喉道为主。总体上属于中低孔、特低渗型储层,纵向上随着埋深加大物性变差,平面上南部物性好,北部物性差。影响储量储集性能的因素有岩性、岩相带、填隙物、分选性和成岩作用。

The characteristics and influential factors of reser- voirs of Member 3 of Shahejie Formation in the area of Leng35 wellblock,Westen basin of Liaohe are studied by core,casting thin section,X-diffraction,porosity and per- meability analysis,mercury intrusion method etc.The re- sult shows the deposition environment of the area is a con- tinental lake deposition environment in partly damp and partly arid lower than cold geologic climate of temperature condition.The reservoir sandstone bodies can divided into two types:The submarine gravity flows and fan in the bottom of lake.Reservoir rocks are primarily litharenite feldspar and mixed sandstones;the pores of reservoirs don 't grow and distribute non-uniformitly,they are principal ly micro-thin and extremly-thin pore throats.As a whole,the reservoirs possess middle-low porosity and specially low permeability,physical properties decrease a- long with depth and that of the south is better than the north.LithologicaI character,sedimentary facies belt,filled -pore matter,separation,diagenesis are the factors influ- encing the reservoir ability.