川西北地区栖霞组—茅口组沉积相研究

发布时间：2018-04-18 10:00

本文选题：川西北地区 + 栖霞组—茅口组　；参考：《西南石油大学》2017年硕士论文

【摘要】：在充分调研前人研究成果的基础上,通过观察四川盆地川西北地区栖霞组—茅口组的多条重点野外剖面,分析和整理多口单井的钻录测井及分析化验资料,结合区域构造背景和岩相古地理概况,对研究区目的层段的地层特征、沉积相类型与特征以及储层特征展开了研究。地层研究方面,本文依据出露地层的颜色、厚度、产状、沉积构造、接触关系、沉积旋回及古生物等宏观标志,总结了栖霞组—茅口组各层段的野外露头特征;结合已有钻井电测曲线反映出来的岩电关系,明确了目的层段内重要的地质界线特征,继而对研究区内目的层段的地层厚度特征、纵横向及平面展布规律做了研究。沉积相研究方面,在充分认识了研究区及其邻区的沉积背景后,根据丰富的沉积相标志,本文将川西北地区栖霞组—茅口组的沉积模式归纳为了具有台地边缘的缓坡型台地模式,总结了台地边缘、浅缓坡、深缓坡、斜坡～盆地4类亚相各自的沉积特征。在对典型剖面和钻井做了纵横向上的沉积相划分后,针对储层段最为发育的栖二段、茅三段研究了平面上的相带展布规律,最终认为古地貌、古构造、同期海平面升降等因素共同影响了沉积相的演化与展布。为了将有关川西北地区栖霞组—茅口组沉积相的认识与生产实际相联系,本文对研究区目的层沉积相与储层之间的关系展开了进一步的剖析。在对储层的储集岩类型、储渗空间类型、储层物性特征和纵横向分布规律有了了解后,通过分析和对比不同沉积相带中的储层发育特征,发现:研究区西部地势高的台地边缘相以颗粒滩沉积为主,又以处于微地貌高地的滩核最易受暴露,利于后期溶蚀作用及白云化作用的改造,形成的“砂糖状”晶粒白云岩为区内最优质的孔隙型储层;相邻的微地貌较低地(如滩翼)则储集性能欠佳。而研究区东部低地势的缓坡相带中以低能沉积为主,基本不具储集性;仅零星分布在局部地貌高地的点滩或点礁能受到后期成岩作用的微弱改造,储集性能虽差,但在后期构造运动影响下可能形成非均性较强的裂缝—孔隙型储层。所以,本文认为:沉积微地貌控制着沉积相带的岩性组成和后期成岩作用的进行,继而控制了储层的分布和物性特征。
[Abstract]:On the basis of full investigation of previous research results, by observing several key field sections of Qixia formation and Maokou formation in northwestern Sichuan Basin, the drilling logging and laboratory data of many single wells are analyzed and arranged.Combined with regional tectonic background and lithofacies paleogeography, the stratigraphic characteristics, sedimentary facies types and characteristics and reservoir characteristics of the target formation in the study area are studied.In stratigraphic research, the characteristics of outcrop in the field of Qixia formation and Maokou formation are summarized according to the macroscopic markers of the outcrop, such as color, thickness, occurrence, sedimentary structure, contact relation, sedimentary cycle and paleontology.Combined with the relationship between rock and electricity reflected by the electric logging curves of drilling wells, the important geological boundary characteristics in the target zone are defined, and the characteristics of formation thickness, longitudinal and horizontal distribution and plane distribution of the target interval in the study area are studied.In the aspect of sedimentary facies research, after fully understanding the sedimentary background of the study area and its adjacent areas, according to the rich sedimentary facies marks,In this paper, the sedimentary models of Qixia formation and Maokou formation in northwestern Sichuan are summarized as the gentle slope platform model with platform margin, and the sedimentary characteristics of platform margin, shallow gentle slope, deep gentle slope and slope ~ basin are summarized.After dividing typical sections and drilling sections vertically and horizontally, aiming at the most developed member of the reservoir, the third member of Mao studies the distribution of facies belt on the plane, and finally concludes that paleogeomorphology, paleotectonics, paleotectonics, paleogeomorphology, paleotectonics,The evolution and distribution of sedimentary facies are influenced by sea level fluctuation and other factors.In order to relate the understanding of the sedimentary facies of Qixia formation to Maokou formation in northwestern Sichuan with the actual production, the relationship between the sedimentary facies and the reservoir of the target layer in the study area has been further analyzed in this paper.After understanding the reservoir rock types, reservoir permeability space types, reservoir physical properties and vertical and horizontal distribution, the reservoir development characteristics in different sedimentary facies zones are analyzed and compared.It is found that the high terrace margin facies in the western part of the study area are dominated by granular beach deposits, and the beach nuclei located in the microgeomorphological highlands are the most vulnerable to exposure, which is conducive to the alteration of late dissolution and dolomitization.The "granulated" grain dolomite is the best porous reservoir in the area, while the adjacent microgeomorphological low ground (such as the beach wing) has poor reservoir performance.In the east of the study area, the gentle slope facies belt of low terrain is dominated by low energy deposition, which is basically not reservoir, and only scattered in the local geomorphologic highlands can be changed weakly by late diagenesis, and the reservoir performance is poor.However, under the influence of late tectonic movement, fractured and porous reservoirs with strong heterogeneity may be formed.Therefore, the sedimentary microgeomorphology controls the lithologic composition and late diagenesis of the sedimentary facies zone, and then controls the distribution and physical characteristics of the reservoir.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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