塔中10号构造带上奥陶统良里塔格组台内礁滩分布研究

发布时间：2018-10-05 13:37

【摘要】：塔中低凸起塔中10号构造带上奥陶统台内礁滩以其丰富的油气资源潜力成为塔中碳酸盐岩油气勘探的重点,但沉积微相分布研究程度低也成为了该区进一步勘探的瓶颈。论文以地层学、碳酸盐岩石学、沉积学等学科理论为指导,运用地质、地球物理等技术手段,在塔中10号构造带上奥陶统良里塔格组地层精细划分与地层分布模式建立的基础上,通过岩心、薄片、测井等相标志,识别研究区各沉积微相类型,分析沉积相纵向发育特征并建立地层对比剖面,分析沉积相横向展布特征；井震结合,划分地震相类型,并建立地震相对比剖面及平面分布图,分析地震相横向及平面分布特征；结合沉积相及地震相的研究成果,建立沉积相演化模式,分析不同类型礁滩体组合的演化特征；综合研究成果,对研究区沉积相平面分布进行分段预测,明确礁滩体有利分布区。研究区良里塔格组自下而上可划分为五段、12个小层,地层厚度具有两边薄中间厚的变化特征。塔中10号构造带良里塔格组主要岩石类型有砂屑灰岩、生屑灰岩、藻粒灰岩、粒屑泥晶灰岩、泥晶灰岩、隐藻泥晶灰岩和格架岩七种岩石类型,其中以砂屑灰岩和生屑灰岩为主,含量分别为45.7%和24.35%。FMI成像测井相分为层状、块状、斑状相,其含量分别为56.18%、19.64%和24.18%。研究区沉积相分为台内滩,台内缓坡、台内洼地、台内礁丘、台坪5个亚相及鲕粒滩、(生屑)砂屑滩、核形石滩、礁(丘)核、礁(丘)坪、丘(翼)、藻坪、泥灰坪等8种沉积微相,主要以(生屑)砂屑滩和台内点丘微相为主。沉积相纵向上表现为良五段时期为台内滩亚相沉积；良四段晚期海平面升至最高,为台内洼地亚相沉积；在良三-良二段时期沉积了一套台内洼地、台内缓坡的垂向组合；良一时期沉积了一套台内缓坡、台内点丘、台内滩及台内洼地的垂向组合,顶部发育一套较厚的核形石滩。横向上,塔中10号带北西-南东向,礁滩体的发育规模自西向东逐渐变大,厚度逐渐增大,灰泥丘主要在良二段的中部发育；北东-南西向,表现为隆凹相间的沉积格局,高能滩体之间为台内缓坡至洼地的低能沉积。根据地震几何反射特征,将良里塔格组地震相分为丘状外形、弱-中强振幅相；丘状外形、强振幅、中等连续相等7种地震相类型。丘状反射和中弱振幅亚平行连续或断续反射主要分布于塔中10号带内部的高能滩体和丘滩体发育区,中-强振幅平行连续反射主要分布于过渡区台内缓坡和台内洼地沉积。平面上台内礁滩体在塔中10号构造带内呈带状分布,台内滩之间以台内缓坡及台内洼地发育为主,良一段至良三段是台内礁滩体发育的有利层位。其中台内滩、台内礁丘为有利相区,为储层研究及进一步勘探的重点。论文丰富了塔中地区开阔台地沉积研究,并可以为研究区下一步油气勘探提供了一定的指导。
[Abstract]:The reef beach in the Ordovician platform of Tazhong No. 10 structural belt in the middle uplift of Tarim Basin has become the focus of hydrocarbon exploration for carbonate rocks with its rich potential of oil and gas resources, but the low degree of sedimentary microfacies distribution has also become the bottleneck of further exploration in this area. Guided by the theories of stratigraphy, carbonate petrology, sedimentology and so on, the paper applies geological, geophysical and other technical means. On the basis of fine stratigraphic division and formation distribution model of the Litag formation in Tazhong No. 10 structural belt, the sedimentary microfacies types in the study area can be identified by means of core, thin slice, logging and other facies markers. The longitudinal developmental characteristics of sedimentary facies and the establishment of stratigraphic correlation section are analyzed, the horizontal distribution characteristics of sedimentary facies are analyzed, the types of seismic facies are classified by combining well and earthquake, and the correlation section and plane distribution map of seismic facies are established. The characteristics of lateral and plane distribution of seismic facies are analyzed, the evolution model of sedimentary facies is established, and the evolution characteristics of different types of reef and beach assemblages are analyzed. The stratigraphic distribution of sedimentary facies in the study area is forecasted, and the favorable distribution area of reef and beach body is determined. The Lianglitag formation in the study area can be divided into five sections from the bottom to the top with 12 sublayers. The thickness of the strata has the characteristics of thin and intermediate thickness on both sides. The main rock types of Lianglitag formation in Tazhong No. 10 structural belt are sandclastic limestone, bioclastic limestone, algal limestone, granulated marl limestone, cryptic algal marl limestone and framework rock. Among them, sand limestone and bioclastic limestone are dominant, the content of which is 45.7% and 24.35%.FMI imaging logging facies are stratiform, block and porphyry respectively, and their contents are 56.18% and 24.18%, respectively. The sedimentary facies in the study area are divided into Taiwan beach, gentle slope in platform, depression in platform, reef hill in platform, five subfacies in platform and oolitic beach, sand and debris beach, core stone beach, reef (hill) core, reef (wing), algal flat, etc. There are 8 kinds of sedimentary microfacies, such as mudstone flat and so on. The sedimentary facies are as follows: the fifth member of the Yangtze formation is the subfacies of the flat in the platform, the sea level of the fourth member rises to the highest level, and the subfacies of the depressions within the platform are deposited in the period of the third and the second member of Liang Sanliang, and the vertical assemblage of the gentle slope in the platform is deposited. A set of gentle slope, dome, beach and depressions within the platform were deposited in Liang-1 period, and a set of thicker nuclear rocky beach was developed at the top of the platform. Horizontally, in the NW-SE direction of Tazhong No. 10 belt, the scale and thickness of the reef body gradually increased from west to east, and the plaster mound mainly developed in the middle of the second member of Liang, and the sedimentary pattern of uplift and depression appeared in the NE-NW direction. Between the high energy beach bodies is the low energy deposit from the gentle slope to the depression in the platform. According to the characteristics of seismic geometric reflection, the seismic facies of the Lianglitag formation are divided into 7 types of seismic facies: mound shape, weak-medium strong amplitude facies, mound shape, strong amplitude and medium continuous equal seismic facies. The mound reflection and the moderate and weak amplitude subparallel continuous or intermittent reflection are mainly distributed in the high energy beach body and the hilly body development area in the Tazhong 10 belt, and the moderate and strong amplitude parallel continuous reflection mainly distribute in the gentle slope and depositional depositions in the transitional area. There is a zonal distribution of reef beach in Tazhong No. 10 tectonic belt, in which gentle slope and depressions are dominant, and the Liangyi to the third member is the favorable horizon for the development of the reef beach body in Tazhong. Among them, the beach and reef mound are favorable facies area, which is the focus of reservoir research and further exploration. This paper enriches the study of open platform sediments in Tazhong area and provides some guidance for further oil and gas exploration in the study area.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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