塔里木盆地塔中地区中、上奥陶统生物礁滩特征及储集体预测

塔里木盆地塔中地区中、上奥陶统发育生物礁濉，主要包括生物礁、生屑濉和灰泥丘3种，在测井曲线上表现为低自然伽马、低声波时差和高电阻率性质，在地震反射记录上有直接或间接特征。纵向上礁滩发育分为两个期次，由早期礁滩向晚期丘滩转化，并有向台内迁移的趋势；平面上多呈带状分布于构造发育带、断层上盘、台地边缘、古地貌凸起、台内缓坡以及地貌坡折带附近。早期礁濉主要分布于塔中1号断裂带附近的台缘相，在Z1井-TZ23井的台内低隆处见台内礁濉，偶见台内点礁（TZ35井），在地貌上发育于古凸起、台内缓坡或者地貌变化坡折带；晚期丘濉主要分布于10号断裂带附近的台缘相，在台内低隆亦见台内滩（TZ23井-Z1井），古地貌上发育于塔中凸起或台内低隆等部位。图4表1参10

Distribution of the Middle-Late Ordovician reef bank reservoir in Central Tarim Basin

Reef bank facies,developed in the Middle-Late Ordovician in the Central Tarim(Tazhong area),includes organic reef,bioclastic bank and lime-mud hillock.The reef bank in logging curves has lower SDT,lower gamma,and higher resistance rate.The seismic reflection has direct or indirect characteristics.The reef-bank reservoir can be vertically divided into two periods: the earlier period is dominated by reef-bank,while the later period by lime-mud hillock.The migratory trend is toward platform.Horizontally,the reef bank is distributed,in the form of strips,in the developed tectonic zones, hanging walls,paleogeomorphic bumps,platform margins,and geomorphic breaks.The earlier reef bank is mainly distributed nearby the fault zone of Tazhong No.1 and inside the platform along Well Z1-TZ23.The later reef bank is mainly distributed nearby the No.10 fault zone and inside the platform along Well Z1-TZ23.