苏里格气田东区奥陶系马家沟上组合储层特征及主控因素分析

奥陶系顶部马家沟上组合(马五1-马五4)风化壳储层是苏里格气田东区下古生界主要产气储层,其中马五1+2及马五41是该区块的主力产气层.在前人研究成果的基础上,通过岩心观察、室内薄片分析及扫描电镜、阴极发光等测试分析认为:苏里格气田东区马家沟上组合储层岩石类型以含膏粉晶-泥粉晶白云岩为主,储集空间以膏模孔+溶缝为主;储层受沉积、成岩、岩溶古地貌及构造共同控制,沉积-成岩是白云岩储层的主控因素,有利沉积相是储层发育的基础,成岩作用决定了最终储层空间的形成,构造对储层主要起到沟通渗滤作用,而岩溶古地貌从宏观上控制着储集空间的发育程度和天然气储集保存状况.

Analysis on the Main Controlling Factors and Characteristics of the Upper Combination of Ordovician Majiagou Formation in the Eastern Part of Sulige Gasfield

On the top of the Ordovician, the weathering crust reservoir in the upper combination of Majiagou Formation (M51 and M54) is the main gas reservoir of Lower Palaeozoic in the eastern part of Sulige gasfield. The M51+2 and M541 are the major gas production reservoir in this gasfield. Based on previous researches, the authors conducted studies including core observation, indoor thin-section analysis, scanning electron microscope and cathode luminescence. Conclusions have been drawn that the main rock type is cream powder-mud powder crystal dolomite, and the main reservoir space type is gypsum hole and karst seam; the reservoir is controlled by sedimentation, diagenesis, lava palaeo-geomorphology and tectonics; sedimentation and diagenesis are the main controlling factors, the favorable sedimentary facie is the basis of reservoir development; diagenesis determines the final formation of reservoir space; the structure of reservoir affects the reservoir communication and infiltration; the karst geomorphology controls the development degree of the reservoir space and reservoir preservation condition in a larger sense.