【摘要】：論文以地層學(xué)、碳酸鹽巖石學(xué)、沉積學(xué)等學(xué)科理論為指導(dǎo),運(yùn)用地質(zhì)、地球物理等技術(shù)手段,在巖石學(xué)、沉積構(gòu)造、生物等相標(biāo)志識別的基礎(chǔ)上,劃分沉積微相類型,分析沉積微相縱向發(fā)育特征；通過沉積微相對比剖面分析沉積相橫向展布特征；井震結(jié)合,劃分地震相類型,并建立地震相對比剖面及平面分布圖,分析地震相橫向及平面分布特征；結(jié)合沉積相及地震相的研究成果,建立沉積相平面展布及分布模式,預(yù)測有利相帶分布。 塔中Ⅲ區(qū)奧陶系良里塔格組劃分為五個巖性段,細(xì)分為12個小層。大部分地區(qū)缺失良四段、良五段地層。整體上良里塔格組地層自南向北、自西向東有逐漸增厚的趨勢。 研究區(qū)沉積相劃分為開闊臺地相和臺地邊緣相兩個相帶,開闊臺地相可進(jìn)一步劃分為臺內(nèi)灘、灰泥丘和臺內(nèi)洼地、臺內(nèi)緩坡、灘間海亞相；臺地邊緣相可劃分為臺緣灘、灰泥丘、灘間海亞相。開闊臺地中優(yōu)勢相為臺內(nèi)洼地、灘間海亞相,分別占沉積相總比的34%和28%,臺內(nèi)灘與灰泥丘發(fā)育較少,分別占17%和10%,臺內(nèi)緩坡占比13%。臺地邊緣相中臺緣灘較發(fā)育,占沉積相總體的62%,其次發(fā)育灰泥丘沉積,所占比例為23%,灘間海亞相發(fā)育較少,僅為15%。闡述了沉積相在橫向上的展布規(guī)律,開闊臺地中臺內(nèi)灘、灰泥丘亞相的厚度較小、連續(xù)性差；灘間海與臺內(nèi)洼地亞相在開闊臺地中發(fā)育規(guī)模大,橫向上連續(xù)性好。臺地邊緣相中臺緣灘發(fā)育規(guī)模較大,延展性強(qiáng),灘體之間多以小規(guī)模的灘間海亞相相隔,灰泥丘較發(fā)育,具有一定連續(xù)性。 塔中Ⅲ區(qū)良里塔格組地震相可劃分為丘狀外形、弱-中強(qiáng)振幅相；丘狀外形、強(qiáng)振幅、中等連續(xù)相等7種地震相類型。丘狀反射和中弱振幅亞平行連續(xù)或斷續(xù)反射對應(yīng)于臺地邊緣相帶中的高能臺緣灘沉積,中-強(qiáng)振幅平行連續(xù)反射主要對應(yīng)開闊臺地內(nèi)部的臺內(nèi)洼地和灘間海沉積。 平面上顆粒灘沉積主要發(fā)育在臺地邊緣相中,分布范圍較廣；在開闊臺地內(nèi)部顆粒灘數(shù)量減少,零星分布于大規(guī)模的臺內(nèi)洼地與灘間海之間。良里塔格沉積時期,海平面逐漸升高水體加深,高能灘體沉積逐漸減少,臺地邊緣相帶變窄,低能灘間海、臺內(nèi)洼地亞相逐漸增多,開闊臺地范圍增加。其中良三段灘體較為發(fā)育,良二段為主要的灰泥丘發(fā)育層位,良一段灘體規(guī)模較小。 本次研究豐富了塔中地區(qū)的沉積研究,并可以為研究區(qū)下一步油氣勘探提供了一定的地質(zhì)指導(dǎo)。
[Abstract]:Guided by the theories of stratigraphy, carbonate petrology and sedimentology, the paper classifies sedimentary microfacies on the basis of the identification of lithology, sedimentary structure and biological facies by means of geology, geophysics and other technical means. The longitudinal developmental characteristics of sedimentary microfacies are analyzed, the lateral distribution characteristics of sedimentary facies are analyzed through sedimentary microfacies correlation profile, the seismic facies types are classified by well shock combination, and the seismic facies correlation profile and plane distribution map are established. The transverse and plane distribution characteristics of seismic facies are analyzed, and the distribution pattern of sedimentary facies is established to predict the distribution of favorable facies zone by combining the research results of sedimentary facies and seismic facies. The Lianglitag formation of Ordovician in Tazhong III area is divided into five lithologic sections and subdivided into 12 sublayers. The formation of the fourth formation and the formation of the fifth member of the formation are missing in most areas. As a whole, the strata of the Lianglitag formation are gradually thickening from south to north and from west to east. The sedimentary facies in the study area can be divided into two facies zones: open platform facies and platform margin facies. The open platform facies can be further divided into inner platform beach, plaster mound and platform depression, gentle slope within platform, subfacies between flats, platform margin facies can be divided into platform margin beach, Plaster mound, interbeach subfacies. The dominant facies in the open platform are the intra-platform depressions and the interbeach subfacies, which account for 34% and 28% of the total sedimentary facies, respectively. The development of the flat and the mound in the platform is less, accounting for 17% and 10%, respectively, and the gentle slope in the platform is 13% of the total sedimentary facies. In the platform margin facies, the platform margin beach is relatively developed, accounting for 62% of the total sedimentary facies, followed by the development of the mud mound deposit, accounting for 23%, and the sea subfacies between the beaches is less, only 15%. The regularity of distribution of sedimentary facies in the horizontal direction is expounded. The thickness of the inner beach in the open platform is small and the continuity is poor, and the subfacies between the beach and the subfacies of the depression within the platform has a large development scale in the open platform and good horizontal continuity. In the platform margin facies, the platform margin beach has a large scale and strong ductility, and the beach body is mostly separated by small scale interbeach subfacies, and the plaster mound is more developed and has a certain continuity. The seismic facies of Lianglitag formation in Tazhong 鈪，

本文編號：2218973