四川盆地飞仙关组高能鲕滩储层地震层序识别

四川盆地泛开江—梁平海槽的形成、发展和消亡过程对下三叠统飞仙关组沉积相的演化和鲕滩储层的分布有着明显地控制作用,也因而决定了鲕滩气藏的分布。鲕滩储层的发育与沉积前的古地貌密切相关,台缘高能鲕粒滩储层是飞仙关组最重要的储层,寻找有利的古地貌和高能鲕滩储层的关键是识别出飞仙关组早期高位域与晚期高位域的沉积特征。利用地震层序预测技术,将四川盆地飞仙关组飞一段至飞三段划分成4套四级地震层序,利用地震层序分析方法研究飞四段沉积前各地震层序顶界古地貌格局、高能滩相的发育特征及迁移规律特征。从空间上直观地了解不同时期古地貌的变迁情况,从区域上识别晚期高位域高能滩储层发育的层段及所处古地貌位置。结论认为:飞仙关组早期沉积是早期高位域的欠补偿沉积,而非晚期高位域的快速充填沉积。实钻证实,地震层序预测技术适用于勘探开发程度低的地区,可有效提高鲕滩储层的钻探成功率。

Identification of seismic sequences of high-energy oolitic beach reservoirs in the Feixianguan Formation in the Sichuan Basin

The formation, development and dying out of the Kaijiang-Liangping pan-trough in the Sichuan Basin significantly controlled the evolution of sedimentary facies in the Lower Triassic Feixianguan Formation and the distribution of oolitic beach reservoirs, thus determined the distribution of oolitic beach gas pools. The development of oolitic beach reservoirs was closely related with the palaeogeomorphology before their deposition. The high-energy oolitic beach reservoirs on platform edges are the most importa...