四川盆地元坝地区长兴组—飞仙关组高精度层序地层格架的建立及礁滩储集层预测

为进一步落实四川盆地元坝地区上二叠统长兴组—下三叠统飞仙关组超深层海相礁滩大气田沉积相带及储集层发育特征,通过井震互馈建立了高精度等时层序地层格架,并揭示沉积相带展布和储集层发育明显与层序地层格架密切相关。在此基础上,开展了针对台缘礁滩带的沉积相敏感性属性提取、反演及沉积相对应性分析,系统刻画了礁滩体的生长特征。钻井验证分析揭示,依据高精度层序地层格架预测的礁滩储集层发育特征与钻井揭示的情况吻合度高,有效地解释了多口井在礁滩发育相带试获超百万方高产工业气流的原因。刻画了元坝气田陆棚相、台缘斜坡相、台缘相、开阔台地相、局限台地相,及次级相包括生屑滩、台缘礁滩、台缘生物礁、鲕粒滩和滩间海的平面展布特征,为元坝地区勘探开发一体化建设奠定了良好的基础。

Establishment of high-precision sequence stratigraphic framework of the Changxing-Feixianguan Formations and prediction of reef-shoal reservoirs in Yuanba area,Sichuan Basin

To clarify the development characteristics of sedimentary facies and reservoir of ultra-deep large reef-shoal marine gas field of the Upper Permian Changxing-Lower Triassic Feixianguan Formation in Yuanba area of Sichuan Basin,high-precision isochronous sequence stratigraphic framework was established by well-seismic crossfeed mode,and it revealed that the sedimentary facies belt distribution and reservoir development obviously have close relation with the sequence stratigraphic framework. Then,extraction of the sensitive attributes,inversion and the correspondence analysis of sedimentary facies of the platform margin reef-shoal was carried out, and the growth characteristics of reef-shoal were described systematically. The drilling verification analysis reveals that the coincidence degree of the prediction of reef-shoal reservoir development characteristics based on the high precision sequence stratigraphic framework and the drilling results is high. It effectively explained why the gas prodction of the wells developed in reef-shoal facies belt is higher than one million cubic meters. The study further defined and characterized the plane characteristics of shelf,platform margin slope,platform margin,open platform,restricted platform facies and subfacies including bioclastic banks,platform margin reef bank,platform margin reef,oolitic bank and interbank sea in Yuanba area. It will estabish a good foundation for the integration of the exploration and development of Yuanba region.