【作者】 杨帅；

【导师】 陆永潮；

【作者基本信息】 中国地质大学 ， 矿产普查与勘探， 2014， 博士

【摘要】 压性盆地同沉积凸起构造的发育和演化控制着构造古地貌、沉积过程和沉积相的展布等,随着三维地震资料的广泛应用,精细的构造-沉积分析已成为沉积盆地分析的研究热点。本文在对大量实际资料进行综合研究分析的基础上,以塔里木盆地早白垩世的构造背景、沉积充填和层序地层格架研究为基础,对雅克拉凸起构造进行早白垩世同沉积构造特征、构造演化的精细的解剖,并重点研究了同沉积凸起构造对沉积物的物源体系、沉积物输送路径、沉积物堆积样式以及沉积相的展布的控制。结合烃源岩、储层及盖层的展布,总结有利圈闭类型,建立构造-沉积-成藏一体化的研究思路。论文研究取得的主要认识如下：1.厘定了雅克拉凸起的构造性质,并分析了其形成机制。通过地震剖面解释和断层几何形态解剖,系统地研究了雅克拉凸起早白垩世的构造性质,认为其该构造为压性盆地边缘造山带构造应力传递导致盆地内部基底破裂隆升所形成的对盆地起分隔作用的隆起带,即压性盆地破裂冲断隆起带。对于造山带周缘的压性沉积盆地,盆地的收缩是往往是通过反向断层控制的基地隆起实现的,而不是像前陆盆地那样形成薄皮褶皱逆冲带。塔里木盆地早白垩世正是这种造山带周围的沉积盆地,在盆地周缘强烈构造应力的挤压下,盆地内部的基底发生破裂,并发生伴随着基底卷入的垂向隆升作用,从而形成盆地内成排出现的破裂冲断隆起带。2.确定了控制雅克拉同沉积凸起的边界断裂的演化规律。以三维地震数据为基础,应用断层落差法对雅克拉凸起两侧的轮台和牙哈断裂进行断裂活动性分析指出,二者在亚格列木组时期均为逆断层,轮台断裂为凸起南缘的逆冲断裂,而牙哈断裂为凸起北缘的反向调节断裂；牙哈断裂在舒善河组时期发生负反转并在研究区内凸起中东部活动强烈,而西部活动较弱。轮台断裂直至古近系才发生负反转,构造活动性同牙哈断裂一样,具有中东强西弱的特点。3.识别出雅克拉凸起早白垩世同沉积凸起的构造特征。通过地震剖面和钻井揭示,发现雅克拉凸起具有以下同沉积凸起特征：①凸起顶部(浅部)的地层倾角小、凸起两侧(深部)的地层倾角大；②同一套地层的厚度具有凸起顶部薄、两翼厚的特征；③凸起顶部发育不整合面,而两翼则见超覆现象；④同一套地层的岩性由凸起顶部向两翼逐渐变细。4.恢复了早白垩世雅克拉同沉积凸起的地貌特征。通过对三维地震资料的处理和解释,大致恢复了雅克拉凸起早白垩世的构造地貌,凸起整体呈NEE向延伸,东段高且狭窄、西段低且宽缓；分别以凸起南缘的轮台逆冲断裂和北缘的牙哈隐伏断裂为界,可将凸起划分出中央凸起带、北缘斜坡带和南缘断坡带三个次级地貌单元。5.明确了雅克拉凸起早白垩世的构造演化特征。在雅克拉凸起边缘断裂的发育和演化研究的基础上,利用三维地震和钻井资料的综合对比研究指出,早白垩世雅克拉同沉积凸起的构造演化可分为两个时期：(1)同沉积凸起的发育期,该时期强烈的区域构造挤压应力导致凸起的隆升并遭受剥蚀,其沉积响应为在凸起中央凸起带缺失亚格列木组沉积,并在凸起南北两侧的断坡带和斜坡带堆积一套近源的粗碎屑沉积；(2)同沉积凸起的消亡期,该时期区域构造挤压应力减弱导致凸起发生整体沉降以及局部的负反转,凸起被两侧地层逐渐超覆,并且发育向上逐渐变细的沉积序列。同时,雅克拉凸起东、西段的演化特征具有明显的差异性,表现为在凸起发育期,区域的构造应力自西向东逐渐增强,从而形成凸起东高西低的地势特点；在凸起的消亡期,牙哈断裂的负反转强度自西向东减弱,因此该时期仅在凸起上的西部地区形成一些次级构造洼地。6.建立了雅克拉凸起及周缘分散点状物源和短距离输砂模式。利用重矿物组分和碎屑岩组分分析方法,确定了凸起周缘沉积物与远离凸起地区的沉积物并非同一物源,而且凸起的东部与西部物源成分也存在差异。砾岩厚度和含砂率高值区通常被用来指示古河道的位置,通过对雅克拉凸起周缘的砾岩厚度和含砂率统计发现,砾岩厚度和含砂率高值区主要位于凸起边缘断裂的附近,沿垂直于凸起走向的方向砾岩厚度值逐渐减低,顺凸起走向的方向砾岩厚度值变化不定,说明沿凸起边缘断裂发育多个分散点状物源。从砾岩厚度和含砂率高值区的展布特征来看,沉积物的输送路径多垂直于凸起走向且输送距离短。沉积物输送距离受凸起的地貌控制,地貌高差大的凸起东部沉积物输送距离较远,而地貌高差小的凸起西部沉积物输送距离较近。7.确定了雅克拉凸起及周缘沉积相的类型。通过野外露头、测井、录井及取心等资料的综合分析,认为在凸起发育期,沉积相类型主要为扇三角洲相,并识别出扇三角洲平原、扇三角洲前缘以及前扇三角洲三种前缘亚相；在凸起消亡期,沉积相类型主要为滨浅湖相,其中包括滨湖相的滩坝砂体以及浅湖相的泥岩沉积。8.识别出压性盆地内凸起两侧的断坡折和挠曲坡折。在雅克拉凸起的南北两侧分别识别出断坡折和挠曲坡折,其中断坡折位于凸起的南缘,受控于南缘轮台同沉积逆冲断裂,挠曲坡折位于凸起北缘,受控丁北缘牙哈反向调节断裂。通过井震综合的沉积相划分,亚格列木组沉积期的扇三角洲发育在构造坡折之下的下降盘,而舒善河组沉积期滨浅湖的滩坝砂体主要分布在构造坡折之上的上升盘,说明了凸起两侧的构造坡拆控制了沉积相带的展布。9.刻画出受雅克拉同沉积凸起控制的沉积相展布。通过对于研究区近百口钻井的砾岩厚度、砂岩厚度及含砾率的统计,并结合三维地震切片属性的综合分析,确定了凸起发育期和凸起消亡期的沉积相的平面展布。其中在凸起发育期,北缘斜坡带发育斜坡型扇三角洲沉积,南缘断坡带发育断坡型扇三角洲沉积；中央凸起带往往缺失粗碎屑沉积。凸起消亡期,主要发育沿中央凸起带展布的滨岸滩坝沉积。10.提出了雅克拉凸起构造-沉积-成藏综合分析思路。指出雅克拉凸起及周缘有利储层为分布于同沉积凸起两侧的扇三角洲砂体和凸起之上的滨岸滩坝砂体。结合勘探成果和构造-沉积分析,总结出该区三种圈闭类型：中央凸起带的微幅背斜圈闭,北缘斜坡带的地层、砂体上倾尖灭圈闭,南缘断坡带的断层-岩性圈闭。综合该区构造性质解剖、构造对沉积控制和成藏条件分析,提出雅克拉凸起构造-沉积-成藏特征：凸起控制沉积储层分布,凸起边缘断裂提供油气运移通道,凸起叠加边缘断裂控制了有利含油气圈闭的发育。更多还原

【Abstract】 Growth Structures plays an important role on control ancient relief, sedimentary processes and sedimentary facies distribution in compressive basin. With the widespread use of3D seismic data, recently subtle tectono-sedimentary analysis of sedimentary basins has attracted much attention. Based on the expatiation of the tectonic development and sediment filling history, the sequence stratigraphic framework of Early Cretaceous in Tarim Basin, this thesis discusses the growth structures pattern, activity, evolution of Yakela Uplift and their controls on sedimentary processes highlighting on sediments entry, transportation pathway, sedimentary facies distribution. Together with the reservoir-cap combination, finally, this paper accesses the favorable traps distribution and presents integrated model of tectonic-sedimentation-hydrocarbon accumulations. The results could not only enrich the theory of tectono-sedimentary analysis of rift basin in eastern China but also be helpful to guide the oil and gas exploration in the Yakela Uplift. The main results in the thesis are as follows:1. On the seismic sections, Yakela Uplift is the basin basement broken uplift, which is formed in tectonic stress transfer from compressional basin of orogen margin. For Tarim Basin in the Early Cretaceous as well as many compressive basins, the shrinkage of basin is often achieved by antithetic fault controlled basement uplift, rather like the foreland basin that formed fold-thrust belt.2. Analysis of fault activity by the fault throw method in Yakela uplift on both sides of Luntai and the Yaha fault which are boundary fault of Yakela uplift. Luntai fault is in the southern margin of Yakela uplift, meanwhile Yaha fault is in the northern margin of Yakela uplift. On the3D seismic sections, Luntai and the Yaha fault were reverse faults in Yageliemu Formation period. The Yaha fault inversed negatively in Shushanhe Formation period, but until the Paleogene, the Luntai fault occurred negatively inversion. The Yaha and Luntai fault have the same tectonic activity, that is strongly in the middle east of Yakela uplift, but weakly in the western. 3. Combined with the analysis of seismic section, logging, drilling, identify the Yakela uplift has the same sedimentary characteristics in the Early Cretaceous.①Stratigraphic inclination angle in the top of Yakela uplift is small, while stratigraphic inclination angle on the both sides is large.②The stratigraphic thickness of statistics have showed striking differences between the top section and the both wings section in the Yakela uplift, that is the stratigraphic thickness of top is thin and the thickness of wings is thick.③Developed unconformity is easy to be found in the top of Yakela uplift; in the wings of the uplift, there is overlap phenomenon.④The same set of stratum lithology changed fining gradually from top to wings.4. Relying on the processing and interpretation of3D seismic data, Early Crataceous tectonic landform in Yakela uplift is restored approximately. Yakela uplift extends along NEE with tectonic characteristics of high-narrow in east part and low-broad in west part. Respectively according to the Luntai thrust fault in the southern margin and Yaha potential fault in the northern margin, Yakela uplift is divided into three secondary geomorphic unit:the central uplift belt, northern slope belt and southern fault ramp belt.5. Based on the study of development and evolution of the marginal fracture in Yakela uplift, synthetically comparing the3D seismic and drilling data, tectonic evolution of synsedimentary uplift in Yakela is divided into two periods:developmental phase and extinction period.(1) In the development period, the regional structure extrusion stress acted so strongly that the formation in Yakela was tilt-lifted and suffered erosion, correspondingly lead to Yageliemu formation sedimentary gap of the central uplift belt, and a set of proximal coarse clastic sediment accumulated both in northern slope belt and southern fault ramp belt. In addition, the regional structure extrusion stress acted increased gradually from west to east, thus the geographic features is East West High low in Yakela uplift.(2) In the extinction period, the regional structure extrusion stress acted so weakening that the Yakela uplift integrally falling even negative inversion locally, and has been overlapping gradually by lateral layer. Sedimentary sequence of this period is developed to fining upward. Furthermore, negative inversion extrusion stress of Yaha fault weakened from west to east, which conduce to some secondary tectonic depressions formed in the western region of Yakela uplift.6. Using method of analysis heavy mineral components and clastic rock components, sediment is identified not the same provenance between periphery of Yakela uplift and the region far away from the uplift, and the sediment source components differences between the east and the west in Yakela uplift. Conglomerate thickness and gravel content is largely used to localize the ancient channels. Such statistics show a high degree of similarity; all maximum are mainly distributed in the marginal fracture in Yakela uplift and the high values zone reflecting the ancient channel basically,while the value reduce slower towards the vertical strike and the value is unsteadily along the strike. According to those features discussed above, development of sediment source along the marginal fracture be showing scattered points distribution, and sediment transportation pathway is thought to perpendicular to the strike of Yakela uplift generally for short distances. At the same time, considering the sediment transportation distance controlled by the geomorphological features in Yakela uplift, the distance of sediment transportation pathway is long relatively in eastern uplift where the discrepancy in elevation is big and the distance is short in western uplift where the discrepancy in elevation is small.7. We described the sedimentary facies type of Yakela uplift and the periphery. Combined with the analysis of outcrop, logging, drilling, core, the sedimentary facies of Yageliemu Formation is mainly fan delta facies, and three subfacies are fan delta plain, fan delta front and front fan delta respectively; the sedimentary facies of Shushanhe Formation is mainly coastal shallow-lake facies, and the subfacies are consist of bar sand body of lakeshore facies and mudstone of shore-shallow lacustrine facies.8. Fault slope break and bending slope break separately identified located in the south and north sides of Yakela uplift. Fault slope break controlled by the Luntai synsedimentary thrust fault in southern margin of uplift and bending slope break controlled by the Yaha reverse regulation fault northern margin of uplift. Combined with the analysis of seismic facies, logging, drilling, in Yageliemu Formation depositional stage, fan delta sediments developed in the downthrow block of lower slope breaks, in Shushanhe Formation depositional stage, bar sand body of lakeshore facies mainly distributed in the upthrown block of upper slope breaks. It can be proved that the slope breaks between the two sides of Yakela uplift constrains sedimentary facies distribution.9. According to statistical data of hundred wells conglomerate, sandstone thickness and gravel content, combined with the comprehensive analysis of3-D seismic section properties, we described the sedimentary facies distribution of Yakela uplift in Yageliemu Formation and Shushanhe Formation:in Yageliemu Formation depositional stage, fan delta sediments developed on both northern slope belt and southern fault ramp belt; coarse clastic sediment in central uplift belt as provenance is eroded. Bar sand body of lakeshore facies mainly distributed on the central uplift belt.10. Combined with reservoir properties, suitable reservoirs within the sand body is predicted in the fan delta deposited on the periphery of Yakela uplift, while the bar sand body is forecasted in lakeshore facies deposited on the top of uplift. Comprehensive utilization of exploration results, tectono-sedimentary Analysis, three types of traps are presented in the study area:The micro-amplitude anticlinal traps in central uplift belt, sandstone up-dip pinch out traps in northern slope belt and fault-lithologic traps in southern fault ramp belt are a variety of primary traps of Early Cretaceous in Yakela uplift. The Yakela uplift tectonic-sedimentation-hydrocarbon accumulation model is presented as followings:the Yakela uplift exerted an important influence both on the sedimentary facies distribution and on suitable reservoir distribution; the marginal fracture penetrating into the deep source rocks by connecting with shallow reservoirs provide the major pathway of hydrocarbon migration; the Yakela uplift and marginal fracture eventually formed beneficial hydrocarbon trap.更多还原