博兴洼陷重点区块沙四上亚段滩坝薄互层砂体形成与分布预测

发布时间：2018-04-24 15:37

本文选题：滩坝砂体 + 层序地层　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：本论文研究区为东营凹陷博兴洼陷重点区块,研究层位为沙四上亚段。综合研究区地层特征和构造背景,以层序地层学、沉积学、测井地质学、盆地模拟等理论为指导,运用岩心、测录井、地震、分析测试资料,在单井层序划分、连井层序对比的基础上,建立全区层序地层格架,在层序地层格架内对滩坝砂体进行精细解剖,重点研究滩坝主力发育层位中不同类型砂体的垂向演化和平面展布特征,并通过综合分析对控制砂体发育的主要参数进行定量恢复,从而进行砂体分布的预测。主要成果与认识如下:1、层序地层研究:应用层序地层学原理和方法,将研究区沙四上亚段划分为1个三级层序,由下至上包括低位域、湖侵域和高位域3个体系域。其中低位域精细划分为3个准层序组,呈进积式叠加样式;湖侵域包括2个准层序组,呈退积式叠加样式;高位域包括2个准层序组,呈进积/加积式叠加样式。最终确定层序地层划分方案,建立研究区的层序地层格架。2、砂体沉积特征研究:研究区沙四上亚段的沉积环境主要为滨浅湖,滩坝的沉积特征明显。研究区沿岸发育砾质滩坝,内部受波浪影响较大,主要发育近岸坝砂及坝间滩砂沉积,由湖岸到湖盆内部砂体分带性明显。通过岩心、测录井资料、地震资料综合分析,总结了不同类型的滩坝砂体在岩心、测录井、地震上的主要特征。低位域沉积时期,基准面下降,物源的供给充足,湖盆内部滩坝砂体大量发育;湖侵域沉积时期,基准面上升,物源供给范围缩小,湖盆内部砂体几乎不发育;高位域沉积时期,基准面缓慢上升到缓慢下降,相比湖侵域沉积时期物源供给范围增大,湖盆内部砂体零星分布。3、滩坝主控参数定量化:大规模滩坝的形成需要一定的物源供给、合适的古水深。同时,古地貌影响湖盆中砂体的展布,风力作为滩坝形成的原始动力,对滩坝砂体的形成与分布也具有一定的控制作用。在层序划分、砂体沉积特征分析的基础上,选取滩坝重点发育时期,采用不同定量恢复方法对各主控参数进行定量化。研究区的滩坝砂体受控于鲁西隆起处的基岩,属于基岩—滩坝沉积体系,南部金家缓坡带为主要物源区;针对滩坝砂体的特点,利用浪成波痕法与坝砂厚度法结合定量研究区古水深,约2~9米,水体较浅,反映强水动力条件,坝砂体发育的水深大于滩砂体发育的水深;古地貌整体坡度较小,呈现北低南高的地势,地层由南向北倾斜,北部发育次洼区,是接受滩坝沉积的主要区域;通过计算古风速对研究区古风力进行定量恢复,确定低位域沉积时期风级为5~7级,该风力中等,是形成滩坝薄互层砂体的理想条件。4、砂体分布预测:综合控制滩坝发育的主要参数,实现研究区滩坝发育重点层位不同类型砂体分布范围与发育规模的预测。
[Abstract]:The study area is the key block of Boxing sag in Dongying Sag, and the study horizon is the upper part of Sha 4. According to the theories of sequence stratigraphy, sedimentology, logging geology and basin simulation, the stratigraphic characteristics and tectonic background of the study area are synthetically studied, and the core, logging, seismic, analysis and test data are used to divide the sequence in a single well. On the basis of sequence correlation, the sequence stratigraphic framework of the whole area is established, and the fine anatomy of beach bar sand body is carried out in the sequence stratigraphic framework. The vertical evolution and plane distribution characteristics of different types of sand bodies in the main developed horizon of beach dam are studied emphatically. Through comprehensive analysis, the main parameters controlling the development of sand body are quantitatively restored, and the distribution of sand body is predicted. The main achievements and understandings are as follows: 1. Sequence stratigraphy: by using the principle and method of sequence stratigraphy, the upper submember of Sha 4 in the study area is divided into a third order sequence, which consists of three system tracts from the bottom to the top, including the lowstand domain, the lacustrine transgressive domain and the high level tract. The lowstand region is divided into three quasequence groups, which are precession superimposed; the lacustrine transgression area consists of two quasequence groups with retrogradation superposition style; and the high position domain consists of two quasequence groups, which are progradation / accretion superposition style. Finally, the sequence stratigraphic division scheme was determined, and the sequence stratigraphic framework of the study area was set up. The sedimentary characteristics of sand body were studied. The sedimentary environment of the upper member of Sha 4 in the study area was mainly shoreside shallow lake, and the sedimentary characteristics of beach and dam were obvious. In the study area, there are gravelly beach dams developed along the coast of the study area, and the inner banks are influenced by the waves, mainly the inshore bar sand and the interdam beach sand deposits, and the zonation of sand bodies from the lake shore to the interior of the lake basin is obvious. Through comprehensive analysis of core, logging data and seismic data, the main characteristics of different types of sand bodies in core, logging and seismic are summarized. During the period of low level sedimentation, the datum level decreased, the supply of provenance was sufficient, and the sandbody of beach and dam developed in the lake basin, and in the period of lake transgression, the datum level increased, the supply range of material source decreased, and the sand body inside lake basin was almost undeveloped. In the period of high level sedimentation, the datum level rose slowly to a slow decrease, and the supply range of provenance increased compared with the period of lake transgression. The sand bodies in the lake basin are distributed sporadically, and the main control parameters of the beach dam are quantified: the formation of the large scale beach dam needs a certain supply of material sources and an appropriate ancient water depth. At the same time, the paleogeomorphology affects the distribution of sand bodies in the lake basin, and the wind force, as the original driving force of beach dam formation, also controls the formation and distribution of beach and dam sand bodies. On the basis of sequence division and analysis of sedimentary characteristics of sand bodies, different quantitative restoration methods are used to quantify the main control parameters in the key development period of beach and dam. The beach bar sand body in the study area is controlled by the bedrock in the western Luxi uplift, which belongs to the bedrock beach dam sedimentary system, and the Jinjia gentle slope belt in the south is the main source area, in view of the characteristics of the beach bar sand body, The ancient water depth of the area is about 2 ~ 9 meters, which reflects the strong hydrodynamic condition. The water depth of the dam sand body is larger than that of the beach sand body, and the overall slope of the paleogeomorphology is smaller, and the water depth of the dam sand body is larger than that of the beach sand body. It is the main area of receiving beach and dam sedimentation, the paleo-wind speed is calculated and the paleo-wind force in the study area is quantitatively restored, and the wind grade of low-lying area is determined to be 5 ~ 7 grade by calculating paleo-wind speed, and the formation is inclined from the south to the north, and the sub-depression area is developed in the north, which is the main area where the paleo-wind force is recovered. The wind is moderate, and it is the ideal condition for forming the thin interbedded sand body of beach and dam. The sand body distribution is predicted: the main parameters of the development of beach and dam are controlled synthetically, and the distribution range and development scale of different types of sand bodies in key layers of beach and dam development in the study area are forecasted.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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