【摘要】 研究发现塔中地区上奥陶统良里塔格组的台地边缘相带呈近环带状环绕卡塔克隆起分布,从晚奥陶世良里塔格组沉积的早期到晚期逐渐向中央断垒带迁移,北部环带较南部迁移的更为迅速。利用钻井与地震资料,开展了良里塔格组沉积相、古地理、古构造及台地边缘成因等综合分析研究。根据古地形、古构造、水体能量的控制,将该台地边缘带划分为陡坡高台型、断褶高丘型、断褶缓丘型、缓坡低丘型等4种类型,并初步划定了它们在塔中地区的分布。研究表明,不同类型的台地边缘,沉积微相有较大的变化,其上发育着灰泥丘、障积礁、骨架礁等不同类型的生物礁(丘)、滩及复合体;且随着台地边缘向中央断垒带快速的迁移、收缩,形成的礁(丘)滩复合体规模变小,发育不完整。由于处于同生大气成岩环境中,礁、丘、滩及复合体在海平面暂时性相对下降时,发生同生岩溶作用,形成大小不一、形态各异的各种孔隙,能作为有效孔隙保存下来的,分布在台地边缘礁滩复合体内,构成大气成岩透镜体。受后期埋藏岩溶作用及构造破裂作用的控制,储层储渗空间以次生成因的孔、洞、缝为主,层间和层内非均质性较强。塔中地区良里塔格组有4～6期大气成岩透镜体,断褶缓丘型、缓坡低丘型台地边缘礁滩复合体的大气成岩透镜体发生频率高,单层厚度较薄。台地边缘相带的分布控制了有利的成藏区域;经过改造的粒屑滩和礁核部位多发育优质储层,控制了油气的富集高产。顺西坡折带和卡4坡折带礁滩相发育,油源条件好,是有利勘探区。更多还原

【Abstract】 The carbonate platform margin of Upper Ordovician Lianglitage Formation was encircling along the Kartarke uplift,with a small gaping at western,in Tazhong area,Tarim basin.From the early to the later stage of the Late Ordovician Lianglitage Formation depositional,the platform margin migrated stepwise to the Center Faulted Zone of Kartarke uplift,and the northern of the encircling zone of platform margin migrated faster than the southern.Based on the data of wells,logging,seismic profile and other relevant analysis test,we have researched sedimentary facies,palaeo-geography,palaeo-structure and genetic model of the platform margin.According to paleo-topography,paleo-structural and waters energy environment,the four types of platform margin are divided,including steep slope-high terra,fault-high mound,fault-low mound,gentle slope-low mound,and their distribution are identified in Tazhong area.The study reveals that the different kind of platform margin had various micro-sedimentary facies and developed distinctly framework reef,barrier reef,lime mud mound and reef(mound)-bank complex.The reef(mound)-bank complex occurred frequently,decreased in size and developed immature with the platform margin migrated fast.Being in contemporaneous atmogenic rock environment,reef(mound)-beach complexes generated syn-depositional karstification,miscellaneous pores were formed when sea level was relative fall.The preserved effective pores distributed in reef(mound)-beach complexes on platform margin,formed the atmospheric lithogenic lens.Influenced by buried karstification and tectonic disruption,secondary pore spaces are developed that are corrosion pores,residual intergranular pores,and fissure pore spaces,with nonhomogeneous in intrabed and interlayer.The atmospheric lithogenic lens with 4 to 6 stages are recognized in research area,some of them were developed frequently and monolayer thickness were thin in which reef(mound)-beach complexes exists on fault-low mound and gentle slope-low mound type of platform margin.To summarize,the favorable reservoir plays are controlled by platform margin zones,high-quality vuggy reservoirs are developed in reef beach complexes,especially grain-clastic bank and reef core reconstructed by later buried karstification and tectonic disruption.Shunxi slope-break zone and Ka-4 slope-break zone developed reef beach complexes and approached source rock are new favorable prospect plays.更多还原