塔中I号断裂带中奥陶统灰岩储层特征

塔中 I号断裂构造带是塔里木盆地中的一个重要油气聚集带 ,中奥陶统灰岩是其最主要的储集层。中奥陶统沉积时期 ,该带位于碳酸盐台地边缘 ,发育粒屑滩、生物礁和灰泥丘沉积。这一沉积相带决定了该带中奥陶统灰岩储层明显好于其周缘地区。岩心及薄片观测结果表明 ,该区灰岩储层的主要储集空间包括孔隙、裂缝和溶洞等 ,它们在不同部位构成不同的组合类型。岩石物性分析显示 ,灰岩储层的基质孔隙度较低 ,绝大部分属低孔、特低孔储层 ,渗透率分布较宽 ,但总体仍偏低。沉积相类型、构造作用和成岩作用是影响该区储层发育程度的主要因素 ,在它们的共同影响下 ,不同层位、不同井区间的储层差别也较大。

Reservoir Characteristics of the Middle Ordovician Limestone in the Structural Belt of Fault No.1, Central Tarim Basin

The structural belt of fault No 1 in the central Tarim basin is an important zone for hydrocarbon accumulation ,a reservoir dominated by the middle Ordovician limestone During the middle Ordovician, this belt is situated on the margin of carbonate platform where grain bank, reef and mud mound were well developed Affected by the sedimentary facies, the reservoir from the middle Ordovician limestone in this structural belt is much better than that in the peripheral regions The observation of cores and thin sections demonstrates that the reservoir spaces are dominated by pores, fissures and caverns combined at various locations, and that the reservoir is characterized by a lower matrix porosity and a broad distributed permeability Their development is limited substantially by the type of sedimentary facies, diastrophism and diagenesis However, reservoirs in various positions are different each other under the influence of these characteristics