川东铁山—黄泥塘地区飞仙关组鲕滩储层主控因素

根据岩心、物性、压汞、薄片等资料,对川东铁山—黄泥塘地区飞仙关组鲕滩储层的特征及成因进行研究。结果表明:飞仙关组鲕粒储集岩以鲕粒云岩和鲕粒灰岩为主,主要储集空间为残余粒间孔、粒间溶孔、粒内溶孔和铸模孔;鲕滩储层基本属于中孔、中渗特征,局部井段存在高孔、高渗层;储层的发育程度受沉积环境、海平面相对变化和成岩作用影响,沉积环境决定了鲕滩储层分布范围,为典型的相控型储层,受次级海平面变化影响,形成了本区飞仙关组多旋回滩体叠置样式,并有利于鲕滩早期云化及溶蚀,优质储层主要发育在单滩体中上部;而优质鲕滩储层的主要储集空间为原生粒间孔和早期溶蚀及云化作用形成的早期孔经埋藏溶蚀改造而成,储层为早期孔保存叠合构造破裂-埋藏溶蚀成因。

Main controlling factors of Feixianguan Formation oolitic shoal reservoirs in Tieshan-Huangnitang Area, eastern Sichuan Basin

Based on the data of core observation,physical property analysis,mercury penetration and slices,this paper studies the characteristics and genesis of Feixianguan Formation oolitic shoal reservoir in Tieshan-Huangnitang Area,eastern Sichuan Basin.The reservoir rocks are mainly oolitic dolomite and oolitic limestone.The main pore spaces of reservoir are residual intergranular pore,intergranular dissolved pore,intragranular dissolved pore and moldic pore.The oolitic shoal reservoir has medium porosity and permeability,and the high porosity and permeability is only in local intervals.The development degree of reservoir is controlled by the sedimentary environment,the sea-level change and diagenesis.Sedimentary environment determines the distribution range of oolitic shoal reservoir,which is typically facies-controlled reservoir.Influenced by the frequent changes of subsea level,the stacked pattern with multi-cycle is formed,which is favorable to primary dolomitization and dissolution.Good reservoirs mainly develop in the center and upper of shoal in Feixianguan Formation.The genesis research shows that the main reservoir spaces of good oolitic shoal reservoir are primary intergranular pore and the early pores formed by primary dissolution,dolomitization and burial dissolution.The genesis of oolitic shoal reservoir is preservation of primary pore and tectonic disruption-burial dissolution.