论文部分内容阅读
徐州大北望地区寒武系为华北地台陆表海环境的典型沉积建造,寒武系碳酸盐岩生油潜力及储集层发育情况都有待于研究,对典型剖面进行分析研究具有重要油气地质意义。通过分析本区寒武系岩石学及陆表海沉积环境特征,恢复了区域海平面变化周期及古地理环境。通过综合野外露头与室内分析,研究区寒武系主要发育的岩石类型为碳酸盐岩,其中鲕粒灰岩厚度较大。结合区域构造及沉积背景分析,本区寒武系陆表海环境中发育沉积相类型主要为:潮坪相、浅滩相、局限台地、开阔台地、台地浅滩。本区沉积演化为:早寒武世主要以潮坪沉积为主,中寒武世发生了寒武系最大一次海侵,台地鲕粒滩相较发育,晚寒武世水深逐渐变浅,出现局限海,潮坪环境。分析得出台地浅滩相中发育的鲕粒灰岩及云坪沉积的白云岩为较有利油气储集层。
The Cambrian of Xuzhou North Cambrian is the typical sedimentary formation of the terrestrial sea environment in North China. The potential of carbonate generation and the development of reservoirs in the Cambrian are yet to be studied. The analysis of typical sections has important geological significance . By analyzing the characteristics of Cambrian petrology and land surface sea sedimentary environment in this area, the regional sea level change cycle and paleogeographic environment were restored. Through comprehensive outcrop and indoor analysis, the main types of rocks developed in the Cambrian of the study area are carbonate rocks, of which the oolitic limestone is thick. Based on the analysis of regional tectonics and sedimentary background, the main types of sedimentary facies in the Cambrian terrestrial sea surface environment in this area are tidal flat, shoal facies, confined terrain, open platform and platform mesa. The sedimentary evolution of this area is that the Precambrian is dominated by tidal flat sedimentation, the largest one is the Cambrian marine transgression, the oolite beach is relatively developed in the Middle Cambrian, the water depth of the Late Cambrian is gradually shallow, Limit the sea, tidal flat environment. It is concluded that the oolitic limestone developed in the shoal facies of the platform and the dolomite deposited in the Yunping area are more favorable oil and gas reservoirs.