【作者】 张元高；

【导师】 张明学； 姜传金；

【作者基本信息】 大庆石油学院 ， 地球探测与信息技术， 2006， 硕士

【摘要】 本次论文以松辽盆地北部古中央隆起带为研究目标,采用地质和地球物理相结合的研究思路,运用多种手段和方法,从不同角度揭示古中央隆起带的构造特征及其演化历程,并揭示基底岩性的分布状况。应用地层层序边界不整合分析法并结合地层残余厚度分析,确定了松辽盆地北部古中央隆起带的性质;通过构造沉降史分析,认识了不同时期的构造沉降特点;通过对古中央隆起带的剥蚀量研究,认清了不整合面剥蚀范围和厚度;利用平衡剖面原理编制的构造发育史剖面图,再现了古中央隆起带的演化历程;利用高精度的构造成图和构造要素统计,展现了古中央隆起带的构造特征;在盆地基底演化的大背景下,利用地球物理特性与地质规律相结合的办法,预测了基底岩性的分布。研究结果表明:1、古中央隆起带是一个持续发育的古隆起,在火石岭组地层沉积时期,开始形成,在沙河子组和营城组地层沉积时期,由于差异沉降,古隆起进一步发育,在登娄库组地层沉积时期,古隆起活动开始减弱直到至停止,此后盆地进入整体沉降接受沉积的坳陷期。2、古中央隆起带在营城组地层沉积前和登娄库组地层沉积前,有过两次明显的抬升剥蚀。经地震剖面和钻井资料相结合,估算总剥蚀量可达2200米,其中营城组沉积前为1500米,登娄库组沉积前为700米左右。3、古中央隆起带的形成,在东西向受东边的徐西大断裂和西边的大庆断阶带的阶梯状断层控制,在南北向受三组北西方向转换断层的切割,形成了四个背斜圈闭发育带;北部为升平凸起、卫星凸起和中内泡凸起,中部为昌德凸起,南部为肇州西凸起和源二构造。4、古中央隆起带基底岩性,具有东西分带、南北分块、受基底断裂控制明显的特征。在古中央隆起带上花岗岩大面积分布,总体上呈南北向展布,具弱磁异常和重力负异常特征;其次是千枚岩+板岩混合发育区,主要分布在工区的西北角和肇深7井西侧以及徐西断裂内部;花岗岩+千枚岩混合发育区,主要分布在头台镇以南地区;其它岩性分布范围很小,如:片岩、石英变质岩等,散落在隆起带上。5、圈闭的主控因素是储层的发育程度。古风化剥蚀作用控制着研究区储集体的分布,亦即控制着天然气聚集。斜坡区是最有利的储集体发育区。构造演化过程表明在火石岭-营城组地层中,有利的圈闭是构造影响下的岩性圈闭、地层超覆圈闭及二者联合作用组成的复合圈闭。在登娄库组地层中,有利圈闭是砂砾岩发育区的构造圈闭。更多还原

【Abstract】 Focusing the main research goal on paleo-central uplift belt of northern Songliao basin,guided by the train of research thought of integrating geology and geophysics, and usingmultiple means and methods, this paper reveals the structural characters and the evolutionaryprocess of paleo-central uplift belt in different aspects, and also disclose the distribution statusof basement lithologies. This paper determines the features of the paleo-central uplift belt innorthern Songliao basin by using the method of the unconformity analysis of the stratigraphicsequence boundary in combination with the thickness analysis of relic strata;finds out thetectonic subsidence characters for different periods through the analysis of tectonicsubsidence history;recognizes the erosion range and the erosion thickness of theunconformity surface through the study of eroded thickness on the paleo-central uplift belt;represents the evolution process of the paleo-central uplift belt by means of the tectonicdevelopment history section map compiled according to the balance section principle;exhibitsthe structural characters of the paleo-central uplift belt utilizing the high-precision structuralmap and the statistical information of structure elements;and predicts the distribution statusof the basement lithologies making use of the analysis of the geophysics and the basementevolutionary history.The research of this paper acquired the following several cognitions: 1. The paleo-central uplift belt of northern Songliao basin is a paleohigh with differentialsubsidence and denudation, which includes multiple uplifts and denudations. Thepaleo-central uplift belt start to develop in Huoshiling period, extended intensively in faultdepression period, and ceased developing and was buried and saved in the late deposition ofDenglouku Formation.2. in the late depositional stages of Shahezi Formation and Yingcheng Formation, owingto the basin being elevated in large areas, the range of denudation extended to the total basinand thus both the uplift belt and the slope region suffered from denudation, which resulted inthe 2200 meters of total eroded thickness,1500 meters for the late stage of Shahezi Formationstratum, and 700 meters of total eroded thickness for the late stage of Yingcheng Formationstratum.3. The formation of the paleo-central uplift belt not only was controlled by the easternlarge-scale fracture of Xuxi and the western step faults of Daqing fault bench belt in east-westorientation, but also was incised by two groups of NW-trending transitional faults insouth-north orientation. This led to the formation of three growth zones of anticline trap in thepaleo-central uplift belt: the northern Weixing uplift and Zhongneipao uplift, the middleChangde uplift, and the southern Zhaozhouxi uplift and Yuaner structure.4. The distribution of the basement lithology of paleo-central uplift belt was markedlycontrolled by the basement faults, which resulted in the lithology distribution features ofbelting in east-west oriention and of blocking in south-north orientation. There were largeareas of granite in the paleo-central uplift region along south-north trend, and distributed in awidespread range, especially in the central uplift area where the granite was the mostdeveloped and the types of rocks were almost confined to the only granite with the charactersof slight magnetic anomalies and gravity negative anomalies.5. The slope region was the most favorable development area of the reservoir bodies, andlow-lying area can form a good sealing cap formation. The paleo-weathering effect not onlycontrolled the formation and evolution of the reservoir bodies in the research area, but alsocontrolled the accumulation of natural gas. The evolutionary process of structure for theresearch area indicated that in the depositional period of Huoshiliang-Yingcheng Formation,the dominant traps are not structural traps but lithologic traps, stratigraphic overlap traps andthe combination traps formed by the allied actions of lithologic traps and stratigraphic overlaptraps;while in the depositional stage of Denglouku Formation, the structural traps play adominant role.更多还原