珠江口盆地东沙隆起珠江组碳酸盐岩储层特征及主控因素

通过观察珠江口盆地东沙隆起珠江组钻井岩心、岩石薄片及铸体薄片,结合该区碳酸盐岩层序划分方案,探讨层序界面控制下的岩性、岩相发育特征,以及孔隙发育特征。结果表明,高位体系域发育生物礁灰岩及生屑滩灰岩储层,发育原生孔隙、次生孔隙等孔隙类型。在海侵体系域主要发育潟湖相、台坪相致密灰岩,偶夹台缘滩、台内滩等灰岩储层,后期往往受到成岩埋藏作用的改造发育溶蚀孔洞和裂缝。该区碳酸盐岩的主控因素主要是在高位体系域Ⅳ级海退半旋回暴露条件下形成的次生孔隙、受礁滩相带控制的原生孔隙及其他溶蚀作用控制的次生孔隙。

Characteristics and key controlling factors of Zhujiang Formation carbonate rock reservoir in Pearl River Mouth Basin,China

According to the sequence stratigraphy classification,the paper concludes the characteristics of lithology and lithofacies and the pore characters using the cores and rock slices of Miocene Zhujiang Formation in the Dangsha uplift of the Pearl River Mouth Basin,China.In the HST,there are reef limestone and grainstone of banks.There exist primary pores and secondary pores in the reservoir.In the TST,there are lagoon limestone and platform limestone with tight property.Occasionally there are limestone reservoirs of epiplatform banks and interplatform banks mixing in the lagoon facies. These limestone reservoirs were regular reformed by the burial diagenesis to develop solution holes and cracks.The key controlling factors of the carbonate rock reservoir are the secondary pores happening below the sequence boundary and the primary pores controlled by the bank reef facies.