塔里木盆地某地区奥陶系古岩溶作用机理及控制因素分析

The Mechanism and Controlling Factors of Palaeokarst of Ordovician in a Certain Area of Tarim Basin

古岩溶是一种重要的聚集油气的地质体,储层发育状况和油气聚集的情况比较复杂。塔里木盆地奥陶系碳酸盐岩储层,基质岩性致密,不具备有效的储渗能力,只有岩溶和裂缝储集体为其主要的储集空间,认识该地区古岩溶的作用机理与控制因素是研究碳酸盐岩古岩溶储层的首要问题。通过对塔里木盆地某地区奥陶系一间房组、鹰山组碳酸盐岩的研究,采用将今论古的研究方法,结合前人的研究成果,根据现今岩溶相带的划分,系统的探讨了本研究区古岩溶的作用机理及模式,并综合分析控制古岩溶发育的诸多因素,包括地层岩性、古地貌、古构造、古水文、海平面变化、不整合面、断裂、古气候等等。

The palaeokarst is an important geological body of oil and gas accumulation,and its development of oil reservoir and gas accumulation is relatively complicated.Because of the compact texture,low storage capacity and poor penetration ability of carbonate rocks of Ordovician in Tarim Basin,the palaeokarst and fissures are the main reservoirs of oil and gas.In order to study the reservoir of the carbonate rocks,it is the key point to understand the mechanism and controlling factors of palaeokarst.By combining the results of other researchers,we explored the mechanism and model of palaeokarst,and comprehensively analyzed several controlling factors during the development of Palaeokarst according to the clarification of the karst lithofacies belt at present.The control factors included formation lithology,palaeogeomorphology,paleostructure,paleohydrogeology,eustatic sea level change,plane of unconformity,fracture,paleoclimate and so on.