临汾—运城盆地中生界沉积特征与资源潜力分析

发布时间：2018-05-08 20:36

本文选题：中生界 + 沉积体系　；参考：《西北大学》2015年硕士论文

【摘要】：临汾-运城盆地位于山西省南部,是叠加在华北克拉通之上的新生代断陷盆地。以往的勘探和研究表明,该地区新生代断陷时间新、堆积地层较薄,烃源岩不发育,故缺乏油气资源潜力。但盆地新生界之下是否具有油气资源潜力,以往并未开展专门研究。中-晚三叠世及早-中侏罗世地层是鄂尔多斯盆地及邻区主要的烃源层和石油储层。临汾-运城盆地位于鄂尔多斯盆地中生代富烃凹陷的东延部分之上,因此对该地区中生界进行油气资源分析具有实际意义。根据研究区的地质特点和勘探资料实际情况,本文采用改造型盆地原盆恢复的思路,重点对临汾-运城盆地周缘残留中生界进行系统观测,通过地层对比、沉积相与物源分析、后期改造分析等,确定中生代主要时期的沉积相与盆地沉积范围。在此基础上结合最新收集的钻孔资料,推断新生界基岩地层的时代与展布。对临汾-运城盆地前新生界资源潜力进行了初步探讨。区域地层对比认为,山西地区中-上三叠统铜川组、延长组与今鄂尔多斯盆地延长组对应；下-中侏罗统大同组、云冈组、天池河组,分别与鄂尔多斯盆地延安组、直罗组、安定组对应。中-上三叠统铜川组、延长组在山西地区厚度为280-620m,具有南厚北薄、南细北粗的特点,与鄂尔多斯盆地同时期地层在南北厚度差异及岩性特征上具有一致性。沉积相类型白下而上可识别出辫状河、曲流河、三角洲等,未见边缘相沉积。山西地区下-中侏罗统各组地层南北变化较大。北部大同、宁武-静乐盆地发育全,永定庄组、大同组、云冈组及天池河组均有沉积,厚度650-950m,中-南部榆社、洪洞一带仅残留云冈组、天池河组,厚度250-550m；可识别出冲积扇、辫状河、曲流河等沉积类型。大同组白北而南由含煤性好的三角洲沉积,变为含煤性差的湖相沉积。云冈组底部冲积扇沉积自北而南逐渐变薄,砾岩砾径减小,表明北部接近物源区。结合区域地质研究和对汾渭地堑边缘挤压构造变形现象的分析,认为临汾-运城盆地三叠纪-中侏罗世沉积之后,在晚侏罗世遭受过显著的区域性挤压和抬升事件,晚侏罗世沉积缺失。根据前人对鄂尔多斯盆地下白垩统的厚度恢复,认为临汾-运城盆地在早白垩时期仍可能接受沉积；但晚白垩世该地区以及西侧的吕梁山、鄂尔多斯盆地均整体抬升,遭受剥蚀。新生代早期,受NE-SW向的剪切拉张作用,南部的运城-关中地区于古新世晚期最早发生断陷；而北部临汾地区直到上新世才发生断陷,接受沉积。综合分析,恢复了中生代临汾-运城盆地主要时期的沉积面貌,认为延长组沉积期,临汾-运城盆地与鄂尔多斯盆地为统一大型沉积盆地,塔尔山陷隆以北为河流相、三角洲相为主,以南为湖相沉积；大同组沉积期,研究区内主要为河流沼泽相、三角洲相等沉积类型,相比延长组时期沉积范围大幅度缩小；云冈组-天池河组沉积期,沉积边界在临汾-运城盆地以东,太行山以西,研究区总体以冲积扇、河流相为主,该时期较大同组沉积时期范围进一步缩小。研究表明,中生代主要时期,临汾-运城盆地所在地区均有沉积,但由于后期挤压和抬升构造改造,致使现今断陷内部中生界残存不全。依据最新收集的地热和水文钻孔资料,编制了临汾-运城盆地前新生界分布图,显示仅在临汾-洪洞地区深部地层为下-中三叠统,另有小部分中-上侏罗统,研究区普遍缺失延长组、大同组同期地层。因此临汾-运城盆地中生界勘探潜力不容乐观。虽然中生界潜在烃源层段在断陷内部几乎没有保存,但上古生界石炭-二叠系在断陷深部大范围保存,且近年来煤田勘探工作已证实具有工业开采价值的煤田,故临汾-运城盆地深部的石炭-二叠系具有形成煤型天然气资源的物质条件,值得进一步研究。
[Abstract]:The Linfen Yuncheng basin, located in the southern part of Shanxi Province, is a Cenozoic fault basin superimposed on the North China Craton. Previous exploration and research showed that the Cenozoic fault subsidence time was new, the accumulation strata were thinner and the source rocks were not developed, so the potential of oil and gas resources under the Cenozoic basin was not in the past. The middle - late three - fold and early Middle Jurassic strata are the main hydrocarbon source beds and oil reservoirs in the Ordos Basin and its adjacent areas. The Linfen Yuncheng basin is located on the eastern part of the Mesozoic hydrocarbon rich sag in the Ordos Basin. Therefore, the analysis of the Mesozoic oil and gas resources in this area is of practical significance. On the basis of the geological characteristics and the actual exploration data, this paper uses the thought of the restoration of the original basin of the reformed basin, focusing on the systematic observation of the residual Mesozoic in the periphery of the Linfen Yuncheng basin, through the stratigraphic contrast, the analysis of the sedimentary and the material sources, and the later transformation analysis, to determine the sedimentary facies and the sedimentary range of the Mesozoic main period. Based on the newly collected borehole data, the age and distribution of the Cenozoic bedrock strata are deduced. The preliminary exploration of the potential of the pre Cenozoic resources in the Linfen Yuncheng basin is preliminarily discussed. The regional stratigraphic correlation holds that the middle upper three series of Tongchuan formation in the middle and upper strata of the Shanxi region is corresponding to the Yanchang Formation in the Ordos Basin, the lower middle Jurassic Datong formation, the Yungang formation, The Tianchi River formation, respectively, corresponds to the Yanan formation, the diazo group and the diazepam formation in the Ordos Basin, the middle upper three series Tongchuan formation, the Yanchang group is 280-620m in thickness in the Shanxi area, and has the characteristics of the South thicknesses and the southern thin north. The same period of the Ordos Basin is consistent with the thickness difference and lithology of the north and south. The upper and Middle Jurassic strata in Shanxi area have great changes. The northern Datong, the Ningwu - Jingle basin developed all, the Yongding Zhuang formation, the Datong formation, the Yungang formation and the Tianchi River formation, the thickness 650-950m, the middle - South Yushe, and Hongdong only residual Yungang formation. The Tianchi River group, with a thickness of 250-550m, can identify alluvial fan, braided river, and meandering river and other sedimentary types. The Datong group is deposited in a good coal bearing Delta in the north and south of the Datong group, and becomes a lacustrine deposit with poor coal property. The deposit of the bottom alluvial fan in the Yungang formation is thinning from the north to the South and the gravel diameter decreases. After the analysis of the tectonic deformation on the edge of the Fen Wei graben, it is believed that after the Triassic to Middle Jurassic deposits in the Linfen Yuncheng basin, there were significant regional extrusion and uplift events in the late Jurassic, and the late Jurassic deposition was missing. According to the thickness of the lower Cretaceous in the Ordos Basin, the Linfen Yuncheng basin was considered to be in the basin. The early Cretaceous may still be deposited in the early Cretaceous, but in the late Cretaceous, the Ordos Basin on the west side and the Ordos Basin were all uplifted and eroded. The early Cenozoic was affected by the shear tension of NE-SW, and the early fault of the Yuncheng Guanzhong area in the southern part of the Guanzhong Area in the late Palaeocene, and the northern Linfen region was not broken until the Pliocene. The sedimentary features of the Mesozoic Linfen Yuncheng basin were restored. The sedimentary features of the Mesozoic Linfen Yuncheng basin were restored. The sedimentary period of the Yanchang formation was considered, the Linfen Yuncheng basin and Ordos Basin were the unified large sedimentary basins, the northern part of the taulshan trapping was the river facies, the delta facies was the main and the lake facies deposits in the south, the Datong formation period, the main study area main. The sedimentary types of river marshes and deltaic are equal, compared with the period of Yanchang formation, the sedimentary boundaries of Yungang formation and Tianchi River formation are in the east of Linfen Yuncheng basin, west of Taihang Mountain, alluvial fan and river facies in the study area, and the time period is further narrowed by the sedimentary period of the Datong group. In the main period of the Mesozoic era, the region of the Linfen Yuncheng basin was deposited, but due to the late extrusion and uplift structure transformation, the Mesozoic Mesozoic in the present fault depression was incomplete. According to the latest collected geothermal and hydrologic drilling data, the distribution map of the former Cenozoic in the Linfen Yuncheng Basin was compiled, showing that it was only deep in the Linfen Hongdong region. The Mesozoic in the Linfen Yuncheng basin is not optimistic about the potential of Mesozoic exploration in the Linfen Yuncheng basin, although the potential hydrocarbon source layer in the Mesozoic is hardly preserved within the fault, but the upper Paleozoic Carboniferous Permian is preserved in a large range of deep fault, and the upper Paleozoic Carboniferous Permian is preserved in a large range, and the upper Paleozoic Carboniferous Permian is preserved in a large range. In recent years, coal field exploration has confirmed the coal field with industrial exploitation value, so the Carboniferous Permian in the deep part of the Linfen Yuncheng basin has the material conditions for forming coal type natural gas resources. It is worth further study.

【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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