苏里格东部马五~5储层特征及成藏控制因素

Reservoir Characteristics and Controlling Factors of M55 Sub-member of Majiagou Formation in the East of Sulige Area

近年来,作为鄂尔多斯盆地油气勘探新层段,奥陶系马家沟组马5五亚段取得了天然气勘探的突破。在钻井岩芯观察、测井分析、薄片鉴定、物性分析等基础上,结合生产资料,系统研究了苏里格地区东部马5五亚段碳酸盐岩储层特征,分析了成藏控制因素。认为苏里格东部地区马5五亚段主要储层为白云岩型岩性气藏,气藏与白云岩之间对应关系好,晶间孔是最主要的储集空间类型,其中,中晶白云岩、细晶白云岩和粉晶白云岩的储层物性最好;沉积微相为储层的发育提供物质基础,白云岩控制了有效储层的分布,中—后期埋藏阶段的成岩作用对储层发育和成藏最为有利,鼻状构造对成藏有一定的影响,古岩溶作用对马5五亚段储层的影响不大。

As the new member of oil-gas exploration,breakthrough in oil-gas exploration has been made in resent years at M55 Sub-member of Majiagou Formation in Ordovician. On the basis of the survey of core of well drilling,analysis of well logging, identification of lamela,analysis of physical characteristics,the article studied the reservoir characteristics and analyzed the controlling factors of reservoir in M55 Sub-member of Majiagou Formation in the east of Sulige Area. It suggested that the main reservoir is a dolomite gas pool in M55 Sub-member in the east of Sulige Area and there is fine corresponding relationship between the gas pool and dolomite. The intercrystalline pore is the main type of reservoir space. Among all kinds of rocks,the medium crystalline dolomite,fine crystalline dolomite and powder crystalline dolomite have the best physical characteristics of reservoir. The sedimentary microfacies mainly provided the material basis for the development of reservoir and the dolomite controlled the distribution of effective reservoir. Besides,the diagenesis of buried period in the middle and later period is the most beneficial to the reservoir development. Meanwhile,nose structure has certain influence on the gas pool,while paleokarst takes little effect on reservoir in M55 Sub-member.