塔北地区寒武系层序沉积相及白云岩储层特征分析

发布时间：2018-08-21 10:45

【摘要】：本文以塔北地区寒武系碳酸盐岩为研究对象,运用碳酸盐岩层序地层学、地震地层学、沉积学以及储层地质学等理论,结合区域地质、岩芯观察描述、室内镜下薄片分析、地震剖面、测井曲线、录井等资料,开展本区寒武系层序、沉积相和储层研究,通过储层发育分布与层序、沉积相关系探讨,结合储层发育控制因素,研究工区白云岩储层发育分布。井震充分结合,建立钻井剖面和地震剖面寒武系三级层序格架,本次研究认为塔北地区寒武系以划分为10个三级层序为宜,其中,玉尔吐斯组划为2个三级层序为宜,肖尔布拉克组划为2个三级层序为宜,吾松格尔组划为1个三级层序为宜,沙依里克组划为1个三级层序为宜,阿瓦塔格组和下丘里塔格组划为4个三级层序为宜。三级层序可以实现全区对比,结合地震剖面层序分析,建立研究区寒武系三级层序对比格架。通过岩石镜下薄片观察,根据白云岩结构、构造、颜色、组分的差异,结合研究区岩相古地理、沉积格局,分析得出研究区下寒武统玉尔吐斯组沉积相划为陆棚、盆地相沉积;下寒武统肖尔布拉克组划为盆地、缓坡相沉积,缓坡相又可进一步划分为外缓坡、中缓坡、内缓坡;从下寒武统吾松格尔组到上寒武统下丘里塔格组时,研究区寒武系发育碳酸盐岩台地模式,钻井剖面上沉积相划分为盆地、台地边缘、局限台地,台地边缘又进一步划分为滩间、台缘滩、潮坪微相,局限台地又进一步划分为潮坪微相、泻湖微相、台内滩微相。通过地震剖面划分出沉积相带边界,结合厚度图及已知井点沉积相,玉尔吐斯组平面上沉积相整体上为盆地相;肖尔布拉克组平面上沉积相为缓坡、盆地相;吾松格尔组平面上沉积相为局限台地、缓坡、盆地;沙依里克组平面上沉积相为局限台地、开阔台地、台地边缘、斜坡、盆地相;阿瓦塔格组平面上沉积相为蒸发台地、局限台地、开阔台地、台地边缘、斜坡、盆地相;下丘里塔格组平面上沉积相为局限台地、开阔台地、台地边缘、斜坡、盆地相。通过岩芯、薄片观察和白云岩有序度分析,得出研究区寒武系白云石化作用主要为蒸发泵白云石化机制、渗透回流白云石化机制、浅埋藏白云石化机制、热液白云石化机制。结合录井、测井分析可知,研究区白云岩储层主要为裂缝型储层和溶蚀孔洞型储层。大部分的原生孔隙已消耗殆尽,断裂破碎作用、热液溶蚀作用、风化壳溶蚀作用是研究区寒武系储层发育的主要机制。白云岩储层发育区主要在天山南与岩溶作用有关的储层发育区、受构造断裂控制的热液白云岩储层发育区、寒武系台缘相地区。
[Abstract]:In this paper, the Cambrian carbonate rocks in the north of Tarim Basin are studied. The theories of sequence stratigraphy, seismostratigraphy, sedimentology and reservoir geology are used in this paper, combined with regional geology, core observation and description, and thin slice analysis under indoor mirror. Seismic profile, logging curves, logging data, etc., to study Cambrian sequence, sedimentary facies and reservoir in this area, and discuss the relationship between reservoir development distribution and sequence, sedimentary facies, combined with reservoir development control factors, The development and distribution of dolomite reservoir in the working area are studied. Well and earthquake are fully combined to establish the Cambrian third-order sequence framework of drilling profile and seismic profile. In this study, it is considered appropriate to divide Cambrian into 10 third-order sequences, among which, the Yuertuoshi formation is suitable to be divided into two third-order sequences. The Scholburak formation is suitable to be divided into two third-order sequences, the Wusongger formation to one third-order sequence, the Shairik formation to one third-order sequence, and the Awa tag formation and the lower Qiulitag formation to four third-order sequences. The third order sequence can realize the whole area correlation, combined with seismic profile sequence analysis, the Cambrian third-order sequence correlation framework is established in the study area. According to the difference of the structure, color and composition of dolomite, combined with the lithofacies paleogeography and sedimentary pattern in the study area, it is concluded that the sedimentary facies of the Lower Cambrian Yultux formation in the study area are classified as continental shelf and basin facies. The Lower Cambrian Scholburak formation is divided into basins with gentle slope facies and gentle slope facies which can be further divided into outer gentle slope, middle gentle slope and internal gentle slope, from the lower Cambrian Wisonger formation to the Upper Cambrian Lower Qiulitag formation, The Cambrian carbonate platform model is developed in the study area. The sedimentary facies in the drilling profile are divided into basin, platform margin, restricted platform, and platform margin, which are further divided into interbeach, platform margin and tidal flat microfacies. The limited platform is further divided into tidal flat microfacies, lagoon microfacies and beach microfacies within the platform. By dividing the boundary of sedimentary facies zone by seismic section, combined with thickness map and known well point sedimentary facies, the sedimentary facies on the plane of Yuertuoshi formation are basin facies as a whole, and the sedimentary facies on the plane of Scholburak formation are gentle slope and basin facies. The planar sedimentary facies of the Wusongger formation are confined platform, gentle slope and basin; the plane sedimentary facies of the Shaylik formation are confined platform, open platform, platform margin, slope and basin facies; the sedimentary facies on the plane of Awa tag formation are evaporative platform. Restricted platform, open platform, platform margin, slope, basin facies, and sedimentary facies on the plane of lower Qiulitag formation are limited platform, open platform, platform margin, slope, basin facies. Through core, thin slice observation and analysis of dolomite orderliness, it is concluded that the dolomitization mechanism of Cambrian in the study area is mainly dolomitization mechanism of evaporative pump, permeable reflux dolomitization mechanism, shallow buried dolomitization mechanism and hydrothermal dolomitization mechanism. Combined with logging and log analysis, the dolomite reservoirs in the study area are mainly fractured reservoirs and dissolved porosity reservoirs. The main mechanism of Cambrian reservoir development in the study area is that most of the primary pores have been exhausted fracture fragmentation hydrothermal dissolution and weathering crust dissolution are the main mechanisms for the development of Cambrian reservoirs in the study area. The dolomite reservoir development area is mainly located in the karst related reservoir development area in the south of Tianshan Mountain, the hydrothermal dolomite reservoir development area controlled by structural fault, and the Cambrian platform margin facies area.
【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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