靖安油田五里湾一区长6储层孔隙结构特征

靖安油田五里湾一区是一个大型的低渗透油气开发区，长6储层具有高孔低渗的特征，储层以原生剩余粒间孔隙为主，长石及早期碳酸盐胶结物的溶解是形成次生孔隙的主要原因，中孔（20um-50um)和大孔（50um-100um)是油气的主要储集空间，而细喉（1um-3um)和中喉（3um-7um)则是长6基本的渗流通道，根据均值与细喉以上孔隙所占百分比的关系曲线，可将长6储层孔隙结构分为4种类型，其中1类，II类具有较好的孔渗性，Ⅲ类孔隙结构较差，Ⅳ类为非储层孔隙结构，铸体薄片孔喉图像分析表明，长6储层具有复杂的孔喉分布特征，不同微相孔喉分布及孔隙结构特征是造成油井产能差异的重要因素。

CHARACTERISTICS OF PORE STRUCTURE OF CHANG6 RESERVOIR,WULIWANYIQU JINGAN OIL FIELD

The Wuliwanyiqu of Jingan oilfield is a large-scale,low-permeable development area of oil-gas. The Chang6 reservoir is characterized by high pore and low permeability. The main pore type of the reservoir is primary remained intergranular pore, the dissolution of the feldspar and early carbonate cement results in the secondary pore.Most reserved space is mesopore(20 μm～50 μm)and macropore(50 μm～100 μm),and fine throat(1 μm～3 μm)and midthroat(3 μm～7 μm)is the basic seepage passage. According to relation curve of average value and fine-throat porosity , pore structure of the reservoir Chang6 is divided into four types. Type Ⅰand Ⅱ have well-developed porosity and permeability, type Ⅲ has poorly developed pore structure ,type Ⅳ is of non-reservoir pore structure of non-reservoir. Pore-throat image of thin-section shows the reservoir Chang6 has complicated pore-throat distributed character. Various pore-throat distribution of microfacies and various pore structure characters are important factor that leads to difference of oil-well productivity .