Based on the results of previous researches for the sedimentary facies of upper permian Changxing formation in eastern area of Sichuan,using the theories of sedimentary and sequence stratigraphy,combining with the observation of outcrops and the identification of rock thin sections,and the sedimentary facies' mark of petrology,paleontology and so on,the features of Changxing formation in study area was analyzed.Combined with the newly drilling data and seismic interpretation in the western area around Chengkou-Western Hubei oceanic trough,according to the strata slices technique,the evolution maps heen had drew in sequence frame of Changxing formation and analyzed the distribution characteristic of Changxing formation.Finally,the research showed that the earlier Changxing formation is the carbonate ramp model,the middle-later period of Changxing formation is Carbonate platform model;Besides,the carbonate ramp model is mainly deposited combine with thin-thickness argillaceous limestone and limestone-siliceous limestone at the top of Longtan formation.In the middle-later period of Changxing formation included open platform,platform margin,platform fore-slope,deep water shelf sedimentation zones and so on.Based on the analysis of geology and seismic interpretation,the gainful reservoir facies of Changxing formation have keen,predicted in the study area.According to the factors,they were divided into three rates of the gainful reservoir facies,and the best rates are the biohermal reservoirs and beach reservoirs.%在前人对川东地区长兴组沉积相研究成果的基础之上,运用沉积学及层序地层学理论,结合野外剖面的观察和室内岩石薄片的鉴定以及岩石学、古生物学等沉积相标志,分析研究区长兴组沉积相特征.结合城口-鄂西海槽西侧重点勘探区域最新的钻井资料,以及地震解释资料,依据地层等时切片技术,绘制出层序地层格架内沉积相展布图;并分析其演化规律特征.研究表明:长兴组沉积早期发育碳酸盐缓坡沉积模式,长兴中-晚期发育碳酸盐台地沉积模式.其中,碳酸盐缓坡沉积常以薄-中层泥质灰岩与龙潭组顶部的灰岩-硅质条带灰岩互层相接触.研究区长兴组中-晚期碳酸盐台地沉积主要发育了开阔台地相、台地边缘相、台地前缘斜坡相以及盆地相沉积.结合地质资料和地震解释成果分析,进行研究区长兴组有利储集相带预测;并依据条件划分为3个有利相带等级,其中礁滩发育部位为最有利储集相带.
展开▼
