【作者】 徐翔军；

【导师】 王东坡；

【作者基本信息】 吉林大学 ， 矿物学、岩石学、矿床学， 2007， 博士

【摘要】 伊通地堑为一狭长不对称双断式走滑-拉分断陷盆地,西北缘边界断裂是控制伊通地堑构造演化的主要断裂构造。盆地结构独特与其他类型陆相盆地有着显著的差别,沉积体系和沉积相类型复杂;冲积扇-河流-扇三角洲-湖泊(水下扇)沉积体系;扇(辫状)三角洲-湖泊(水下扇)沉积体系;湖泊(水下扇)沉积体系;河流沉积体系。地堑西北缘独特地质条件下形成特殊类型水下扇——跌水扇。伊通地堑具备了应用层序地层学理论和方法的基本条件,根据层序和体系域划分标志,伊通地堑古近系和新近系分为10个三级层序。依据可控制全区地轴和横向地震剖面及相对应的连井剖面层序地层解译成果,建立了全区等时地层对比格架。根据岩相、地震相、测井相分析建立了伊通地堑层序地层发育模式。构造沉降是本区层序地层发育的决定性因素,气候条件、基底和物源区岩性对层序发育也有不同程度的影响。根据生储盖特征及钻井层序与含油气性的分析,认为大南凹陷层序1、2、3,新安堡凹陷层序3、5、6、为最有利的含油气层序;低水位体系域是重要的岩性地层圈闭发育场所,本次研究优选出7个有利油气勘探区带。更多还原

【Abstract】 Yitong Graben is the south part of Jia-Yi Graben which is great in length / width, being a continental stride-slip full apart basin bounded by faults. The episodic activities of tectonics were strong, the degrees of subsidence were different, and the sedimentations were complex with the point source areas and the paleo-geography of interplaced lakes and fans during the basin evolution. At present, some problems influenced the development of petroleum exploration are dividing and correlation of chronological stratigraphy, sequence stratigraphy and non structural oil traps. Those are focused in this paper to serve the petroleum exploration, specially in litho-straral traps.The interior architectures, structural units, sedimentary fillings of Yitong Graben were controlled strictly by faulting, and the study of structural-sedimentary evolution is a basic work of the analysis of sequence stratigraphy. The key controlling fault is a stride-slip one steeply located in northwestern margin, having complicated changing histories in activity patterns and mechanism during the forming and evolution of the graben. The boundary faults in the southeastern margin were associate faults which had different patterns due to the basement lithography and mechanism. The evolution of the graben had 6 stages that were initial rifting, right-rotation extensional-wresting, lift-rotation extensional-strip-slipping, right-rotation shearing, transverse faulting and thrusting.Under the guidance of modern sedimentology, some sedimentary facies are recognized, including alluvial fan, delta, lucastrine, sub-water fan and fluvial ect., through the integrated study of drilling, logging and seismic facies. The depositional systems developed during Paleocene were follow : (1) alluvial-fluvial-fan delta-lake (sub-water fan) system in lowstand systems tract, (2) fan (braid stream) delta-lake (sub-water fan)system in transgressive and highstand systems tract, (3) lake ( sub- water fan) with on source supplying (lake bay), (4) fluvial system during the ending of the basin. The evolution model and sedimentary filling sequence are set up by analysis the paleo-geography, giving a dividing standard of interior units in a sequence and the recognizing marks of sequence boundaries. The sedimentary covers are divided into 10 sequences ofⅢrank in study area, 7 of the sequence (from sequence 1 to sequence 7)and 21 systems tracts are analyzed, as well as dealing with the relationship between sequence boundaries and the traditional surfaces.Sequence1 is Shuang1 member, Sequence 2 is Shuang2 member, Shuang3 member and lower part of Sheling formation, Sequence 3 is the upper part of Sheling formation, Sequence 4 is Yong1 member, Sequence 5 is Yong2 member, Sequence 6 is Yong3 member and Yong4 member, Sequence 7 is Wan1 member, Sequence 8 is Wan2 member and Wan3 member, Sequence 9 is Qijia formation, and Sequence 10 is Chaluhe formation.The girding of seismic profiles with drills being as framwork to control the strata distribution of the graben, the interpretation of seismic sequence stratigraphy is started with 3D space in different structural units and different locations in the same unit, while the dividing and correlation of high resolution of sequence stratigraphy is started in selected drilling wells sections corresponding with related the seismic profiles using the results of high resolution of sequence stratigraphy in single wells. The reasonable chronological stratigraphic framework is set up using integration of drilling and seimic data to compare and test.The developing model of sequence stratigraphy is special, due to the special tectonic background of Yitong Graben. The model of the deep depression zone in the northwestern margin of the graben is different from that of other continental fault basins both in homeland and oversea, while the model of the fault slope in the southeastern margin of the graben is familiar to that of steep slope of half graben developed in other basin in our country. This developing model of sequence stratigraphy of continental basin is one of asymmetry, both sides’faulting and linearity, in high light of tectonic subsidence and lithography as influences on the development of sequence stratigraphy through dividing and correlation of sequence stratigraphy and analysis of key controlling factors. The integrated sequence is composed of LST, TST and HST.The favorable oil bearing sequences is sequence1,2,3 in Danan depression and sequence 3,5,6 in Xinanbao depression, by the associations of source, reservoir and cover rocks and analysis of oil bearing. LST is important litho-stratal trap locations, developed mainly in the transitional zone between depression and uplift. The sand bodies of sub- water fan and fan delta occurred richly in northwestern margin, led to possibility of litho-fault trap in the hangingwall of growth fault. The deep cut valleys and LST fans occurred during LST, the sub-water fan and fan (braid) delta occurred during TST and HST might litho oil trap, upward tinning stratal trap, unconformity trap as well as complex trap. There are 7 favorable exploration zones in Dnan and Xinanbao depressions.更多还原