蟠龙油田三叠系延长组长6油层致密储层特征研究

Study on Tight Reservoir Characteristics of Chang-6 Reservoir of Triassic Yanchang Formation in Panlong Oilfield

通过岩石薄片、压汞、扫描电镜、常规物性等方法,对蟠龙油田长6储层的特征进行研究,表明该层段储层的岩石类型主要以岩屑长石砂岩为主,储层的孔隙类型为粒间孔隙和溶蚀孔隙,孔隙结构划分为小孔细喉型和细孔—微喉型两种类型。根据储层评价结果,蟠龙油田长6油层主要为四类储层,少量发育五类储层。四类储层主要分布在冯152、冯155、冯158和潘3324等井区,五类储层主要分布在研究区东南部,其中四类储层孔隙度分布为7.1%～10.4%,渗透率分布为0.11～0.73mD;五类储层孔隙度小于7%,渗透率小于0.1mD。蟠龙油田长6储层属典型超低渗—致密油储层。以上研究成果对蟠龙油田将来的精细开发有一定借鉴意义。

Reservoir characteristics of Chang-6 reservoir in Panlong oilfield were studied by means of thin section,mercury injection,scanning electron microscopy and conventional physical properties.The results showed that the reservoir rock types are mainly lithic feldspar sandstone,and the reservoir pore types are intergranular pore and dissolution pore.The pore structure can be divided into two types:pore fine throat type and pore-micro throat type.According to the result of reservoir evaluation,Chang-6 reservoir in Panlong oilfield is mainly type Ⅳ reservoir,and a small amount of type Ⅴ reservoir.Class Ⅳ reservoirs are mainly distributed in the well areas of Feng 152,Feng 155,Feng 158 and Pan 3324,and Class Ⅴ reservoirs are mainly distributed in the southeast of the study area.The porosity distribution of Class Ⅳ reservoirs is 7.1%~10.4%,the permeability distribution is 0.11~0.73 mD.The porosity of Class Ⅴ reservoirs is less than 7%,and the permeability is less than 0.1 mD.Chang-6 reservoir in Panlong oilfield is a typical ultra-low permeability-tight reservoir.The above research results can be used for reference in the future fine development of Panlong oilfield.