巴楚地区巴楚组生屑灰岩段储集层特征与油气成藏

Reservoir Characteristics and Hydrocarbon Accumulation of Bioclastic Limestone Section of Bachu Formation in Bachu Area, Tarim Basin

研究了塔里木盆地巴楚地区石炭系巴楚组生屑灰岩段地层层序,在此基础上,利用岩心资料,研究了生屑灰岩段储集层特征及其分布;应用流体包裹体分析等技术和方法,研究了油气注入成藏史与成藏主控因素。研究区内生屑灰岩段海侵体系域储集层主要岩石类型为颗粒灰岩和白云岩,储集空间类型为孔隙型、孔隙-裂缝型和裂缝型;影响储集层物性的主要因素为沉积作用与成岩作用以及构造作用;最有利的储集层分布在巴楚西部巴什托麦6—麦4井区一带及其周缘;油气藏类型主要为背斜油气藏,其次为裂缝油气藏,至少发生了2次油气注入成藏(海西运动晚期与喜马拉雅运动晚期);提出储集层质量、构造演化、断裂和圈闭是控制油气成藏的重要因素。

This paper studies the stratigraphic sequence of bioclastic limestone section of Bachu formation of Carboniferous in Bachu area of Tarim basin, based on which studies the bioclastic limestone reservoir characteristics and its distribution with core analysis data. Also, using fluid-inclusion analysis technique, this paper studies the hydrocarbon charging and accumulation history and its main controlling factors in this area. It is shown that this reservoir is characterized by grainstone and dolomite in lithology, pore, pore-fracture and fracture in reservoir space type, as well as main factors ＇affecting the reservoir petrophysical property such as sedimentation, diagenesis and tectonic process. The most favorable reservoir could be distributed along and nearby Wellbloek Mai-6 to Mai-4 in western Baehu area. The reservoir type is anticlinal reservoir and fractured reservoir, the former is dominant. There exist at least two periods of hydrocarbon charging and accumulation （Late Hercynian and Late Himalayan movements）. The reservoir quality, tectonic evolution, fault and trap are the important factors controlling the hydrocarbon accumulation in this area.