Based on the analysis of thin sections and physical property of Chang 6 reservoir in Huaqing area,the paper studied the petrology feature,pore styles,the microscopic reservoir structure,characteristics of porosity and permeability as well as the diagenesis.The results suggest that delta sediments and turbidite fan of deep water are the main deposits in the Chang 6 reservoir.Delta front underwater distributary channel and turbidite fan are the main facies belt forming reservoirs of Chang 6 .Lithic arkose sandstones,and feldspathic sandstone are maj or rock developed in this area;the granular pore and secondary feldspar-dissolution pore are the main pore types.Pore throat presents fine pore and fine throat with high micro-heterogeneity. The average porosity is less than 9.5%,and the permeability is below 0.38×10-3μm2 .So Chang 6 reservoir belongs to low porosity and low permeability reservoir. The low-permeability sandstone had undergone complicated diagenesis, especially compaction, cementation and dissolution.The compaction and cementation that lead to porosity loss are the main factors causing low porosity and permeability.But the dissolution,especially dissolving pores in the feldspar and authigenic laumontite largely improves the reservoir property.%通过对华庆地区长6段岩心铸体薄片及物性资料分析,研究了其岩石学特征、孔隙类型、微观孔隙结构特征、孔渗特征及成岩作用。认为研究区长6储层发育三角洲前缘及深水浊积扇沉积,三角洲前缘水下分流河道和上扇主沟道是储层分布的主要相带,主要发育细粒岩屑长石砂岩及长石砂岩、长石岩屑砂岩；粒间孔及长石溶孔是主要储集空间。孔喉分布表现为小孔微细喉,非均质性强；孔隙度平均为9.5%,渗透率平均为0.38×10-3μm2,为一套低孔低渗-特低渗储层。研究区砂岩埋藏后经历的成岩作用主要有压实作用、胶结作用及溶蚀作用。强烈的压实作用、胶结作用是使孔隙大量消失、物性变差的主要原因；而溶蚀作用,特别是长石、岩屑及浊沸石溶孔在很大程度上改善了储层的储集性能。
展开▼
