塔中地区是塔里木盆地的重点勘探区域,奥陶系鹰山组蕴藏了丰富的油气资源.鹰山组发育大套台地相碳酸盐岩,以高能相的台内滩沉积为主.鹰山组埋藏较深,但岩溶储层呈大面积厚层状分布.早奥陶世塔中Ⅰ号断裂使得塔中隆起隆升并遭受强烈剥蚀形成下奥陶统鹰山组顶部风化壳,以孔洞型和裂缝-孔洞型储层为主.通过古地貌恢复、地震属性分析和地震测井联合波阻抗反演技术和方法识别溶洞发育带和断层裂缝发育带,确定出有利储层的分布范围.研究认为,岩性岩相是岩溶型储层发育的重要基础,层间岩溶控制了储层的成层性和横向展布规模,断裂和裂缝网络是岩溶水的主要渗滤通道,埋藏岩溶形成大量有效的缝洞空间,极大地提高了储集性能.研究发现,优质储层主要分布在鹰山组顶面以下120 m地层厚度范围内,横向有一定连通性,在断层、构造裂缝和溶蚀作用下形成统一的储集体,呈准层状展布.%Tazhong is one key exploration area in Tarim basin because the Ordovician Yingshan Formation hosts abundant oil and gas resources. There are a large set of platform facies carbonate rocks developed in the Yingshan Fm. , dominated by high-energy deposition. The Yingshan is buried deeply, but karst reservoir occurs as thick layers distributing in a large area. Early Ordovician fracture Tazhong I resulted in uplift of the Tazhong uplift and was subjected to intense erosion to form a weathering crust at top of the Lower Ordovician Yingshan Fm. The reservoirs is dominated by vuggy and fracture-vuggy type. The paleo-landscape restoration, seismic attribute analysis, seismic acoustic impedance inversion joint logging techniques and methods were employed to identify cave development zone and the fault fracture zone to determine the scope of the distribution of favorable reservoirs. Studies suggest that lithology and petrography is the important basis for development of karst-type reservoir. Interlayer karst controls lamination and distribution scale of reservoir and faulting and fracture are major permeability channel. Hidden karst forms a large amount of available fractured-vuggy space, which greatly improves reservoir properties. The study found that high-quality reservoirs are distributed mainly with the zone between top and 120 m below and form a quasi-layer reservoir with a certain horizontal connectivity linked by faults, structural fissures and dissolution.
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