塔中低凸起东部构造解析及勘探领域分析

Structural Interpretation in Eastern Low Bulge of Central Tarim Uplift and New Areas of Exploration

塔中低凸起是塔里木盆地重要的油气富集单元,其东部早期构造活跃,地质记录丰富,是认识塔中地区地质发育历史和油气成藏条件的窗口。利用钻井和地震资料,进行综合地质建模和构造反演,重建了塔中东部地区古生代构造沉积发育过程。研究表明在中奥陶世区域古隆起的基础上,晚奥陶世良里塔格组沉积期沿古隆起边缘发育台缘礁滩体,晚奥陶世末为构造定型期,塔中地区发生多次强烈的陆内挤压冲断变形,平衡剖面恢复得到塔中低凸起东部水平缩短量为4.5 km。受早期构造活动的影响,该区奥陶系碳酸盐岩储层的油气聚集主要受断裂和裂缝控制,良里塔格组台缘礁滩体是最有利的勘探领域,构造反演表明塔中I号断裂带下盘可能隐伏更大规模的台缘礁滩体,勘探潜力巨大。

In this paper, structural characteristics of eastern part of the central Tarim uplift controlled hydrocarbon accumulation. By data of balanced cross-section and drilled well, we recovered the integrated structural geometry model and each stage of structural deformation, and reconstructed Paleozoic structural-depositional evolution in the eastern part of central Tarim uplift. The platform edge reef flat body was formed along the brim of middle Ordovician palaeohigh in the late Ordovieian Lianglitage depositional stage. Although structure feature was established at end of later Ordovician, several intensive intracontinent compaction and thrust deformation made balance section shorten 4.5m lengthen at eastern low bulge of central Tarim uplift. Under previous structural activity, petroleum accumulation in Ordovician reservoir was controlled by fault and fissure. The platform edge reef flat body in Lianglitage Formation is a profitable area of exploration. The structural recovery suggested that a larger size platform edge reef flat body would he existed under bottom wall of fault NO. 1 of Tazhong as new area of exploration.