鄂尔多斯盆地中东部马家沟组盐下储层特征研究

发布时间：2018-05-21 19:03

本文选题：鄂尔多斯盆地中东部 + 马家沟组　；参考：《成都理工大学》2015年硕士论文

【摘要】：鄂尔多斯盆地广泛分布蓟县系、寒武系、奥陶系碳酸盐岩地层。自1989年发现风化壳岩溶型气田(靖边大气田)以来,碳酸盐岩油气勘探长期未取得实质性进展。近几年,鄂尔多斯盆地碳酸盐岩油气勘探重新受到重视,在古隆起东侧中组合取得了重大勘探突破(3000亿方天然气储量),如苏345等8口井获日产百万方以上高产气流。在中组合勘探研究的启示下,提出膏盐岩下上古煤系烃源侧向供烃成藏新认识,这一新认识使我们认识到膏盐岩下白云岩储层具有较好的烃源条件。因此,本文以《鄂尔多斯盆地下古生界碳酸盐岩沉积演化与天然气成藏地质条件研究》项目为依托,以盆地中东部盐下地区为研究对象,通过野外地质调查,钻井岩芯观察,薄片鉴定、测试分析等技术手段,系统研究了研究区内的沉积相展布规律、储层特征以及盐岩的发育特征,并进行了储层发育控制因素的相关研究,取得了以下几点认识:对盆地中东部马家沟组马五6-马五10小层沉积微相特征及沉积演化过程进行了分析,认为盆地中东部自东向西发育潮上云坪-潮间灰云坪-膏岩洼地(泻湖)的环境。通过钻井岩心观察及室内岩矿鉴定的分析结果,认为盐下地区发育(含)灰云岩、含膏云岩、泥微晶白云岩、残余砂屑云岩、鲕粒白云岩、粉-细晶白云岩及马鞍状白云岩,并对它们的分布和特征进行了研究,认为其中粉-细晶白云岩和含膏云岩可以作为良好的储集体。由于研究区马家沟组白云岩地层时代老,地层经历成岩作用时间长,埋藏深,因此成岩作用较其它地层复杂。本文在分析区内成岩演化过程后,认为白云石化作用、溶蚀作用和去膏化作用具有建设性。压实、压溶作用,充填作用,重结晶作用,去白云石化作用不利于储层发育。系统研究了盐岩的分布规律,认为盐岩与储层的分布受控于海平面的变化影响,海退期形成膏盐岩,海进期形成白云岩储层,二者之间存在四种组合样式。最后总结认为,储层的发育受沉积微相和白云石化作用、溶蚀作用的影响,潮间云坪为有利的微相类型。
[Abstract]:Jixian, Cambrian and Ordovician carbonate strata are widely distributed in Ordos Basin. Since the discovery of weathered crust karst gas field (Jingbian large gas field) in 1989, no substantial progress has been made in carbonate oil and gas exploration for a long time. In recent years, oil and gas exploration of carbonate rocks in Ordos Basin has received renewed attention, and a major breakthrough has been made in the middle assemblage on the eastern side of the paleouplift (300 billion square gas reserves, such as 8 wells such as Su 345 and so on, have been obtained with a daily production of more than one million square meters of high gas flow). On the basis of the inspiration of the middle assemblage exploration, a new understanding of the formation of lateral hydrocarbon supply hydrocarbon reservoir in the upper Paleozoic coal series of gypsum salt rock is put forward, which makes us realize that the dolomite reservoir under the gypsum salt rock has better hydrocarbon source conditions. Therefore, based on the project of Lower Paleozoic Carbonate Sedimentary Evolution and Natural Gas Reservoir formation Geological conditions in Ordos Basin, this paper takes the middle and eastern part of the basin as the research object, through the field geological survey, drilling core observation. By means of thin slice identification, test and analysis, the regularity of sedimentary facies distribution, reservoir characteristics and salt rock development characteristics in the study area are systematically studied, and the related research on the controlling factors of reservoir development is carried out. Some understandings have been obtained as follows: the sedimentary microfacies characteristics and sedimentary evolution process of the Ma-56-Ma 510 sublayer of the Majiagou formation in the central and eastern part of the basin have been analyzed. It is considered that the environment of Yunping-intertidal grey Yunping-gypsum depression (lagoon) is developed in the central and eastern part of the basin from east to west. Based on the results of drilling core observation and laboratory rock ore identification, it is considered that limestone, gypsum, mud-microcrystalline dolomite, residual sandstone, oolitic dolomite, silt-fine-grained dolomite and saddle dolomite are developed in the subsalt area. The distribution and characteristics of them are studied. It is considered that the powder-fine-grain dolomite and gypsum-bearing dolomite can be used as a good reservoir. Because the dolomite strata of Majiagou formation in the study area are old, the strata experienced diagenesis for a long time and deep burial, the diagenesis is more complicated than other strata. After analyzing the diagenetic evolution process in this area, it is considered that dolomitization, dissolution and demoulding are constructive. Compaction, pressure-dissolution, filling, recrystallization and dedolomitization are not conducive to reservoir development. The distribution of salt rock is studied systematically. It is considered that the distribution of salt rock and reservoir is controlled by the influence of sea level change, the salt rock is formed in the regressive period and dolomite reservoir is formed in the sea advance period, and there are four kinds of combination patterns between them. Finally, it is concluded that the reservoir development is affected by sedimentary microfacies, dolomitization and dissolution, and the intertidal cloud flat is a favorable microfacies type.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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