苏里格气田苏东南地区盒8段储层孔隙结构研究

Reservoir pore structure in He 8 formation of the southeastern Sulige Gasfield

利用常规砂岩薄片、铸体薄片、扫描电镜、常规压汞等岩心分析资料从定性到定量的角度分别对苏东南地区盒8段储层的孔隙组合类型与孔隙结构进行研究,按照溶蚀孔与晶间孔的相对含量将孔隙组合类型划分为4类:晶间孔型、溶蚀孔-晶间孔型、晶间孔-溶蚀孔型、溶蚀孔型,并重点分析了4种孔隙组合类型所具有的孔隙结构特征。研究结果表明:晶间孔型的喉道类型主要为微喉道与微细喉道,其孔喉参数分选性好,退汞效率高;除了微喉道与微细喉道之外,溶蚀孔-晶间孔型、晶间孔-溶蚀孔型、溶蚀孔型发育一定含量的细喉道与中喉道,并且细喉道与中喉道的比例随着溶蚀孔含量比例的增加而逐渐依次增大;溶蚀孔型的分选系数与退汞效率整体上低于晶间孔型,由溶蚀孔与晶间孔形成的混合孔隙组合类型具有比单一孔隙类型更差的分选系数与退汞效率。

Study the reservoir pore types and pore structure of He 8 reservoir in the southeast area of Sulige from qualitative to quantitative perspective by conventional sandstone thin section,cast thin section,scanning electron microscopy,conventional mercury injection and data of core analysis. According to the relative content of dissolution pores and intergranular pores,the pore combination type is divided into four categories： intergranular pore,dissolution pore-intergranular pore,intergranular pore-dissolution pore,and dissolution pore. And analyze the characteristics of pore structure with four kinds of pore type.The research results show that： Intergranular pore throat types are mainly micro throat and micro fine throat,and it also has good sorting of the pore throat parameters and higher mercury withdrawal efficiency; In addition to the micro fine throat and micro throat,dissolution pore-intergranular pore,intergranular pore-dissolution pore and dissolution pore also develop some fine throat and medium throat,and fine throat and medium throat ratio gradually increased with increasing proportion of dissolution pore content;The sorting coefficient and mercury withdrawal efficiency of solution pore type is lower than the intergranular pore,Mixed type of pore combination formed by dissolution pores and intergranular pores is of lower sorting coefficient and worse mercury ejection efficiency than the single pore type.