【作者】 刘春艳；

【导师】 马锦龙； 王晓锋；

【作者基本信息】 兰州大学 ， 古生物学与地层学， 2009， 硕士

【摘要】 三塘湖盆地位于新疆维吾尔自治区东北部,西临准噶尔盆地,南临吐鲁番-哈密盆地,东北部与蒙古国接壤,盆地总体呈北西—南东向展布,三塘湖盆地是由不同构造演化时期的原型盆地叠加形成的展布范围较小的复合型含油气盆地。论文在收集和整理三塘湖盆地石炭系相关地质资料的基础上,结合前人研究成果,对三塘湖盆地石炭系烃源岩的有机地球化学特征进行了综合分析和研究,并进行了初步评价,同时试图探讨构造—热事件对烃源岩的改造与影响等科学问题,其主要认识如下:在研究石炭系碎屑岩沉积厚度基础之上,重点对三塘湖地区上石炭统的巴塔玛依内山组（C₂b）、哈尔加乌组（C₂h）、卡拉岗组（C₂k）进行了研究。认为哈尔加乌组（C₂h）是上石炭统泥岩主要沉积期,也是上石炭统的主要烃源岩。其中,哈尔加乌组泥岩大部分为很好—极好的烃源岩,有机质丰度也具有随深度逐渐变好的趋势。三塘湖盆地卡拉岗组泥岩主要以Ⅱ₂—Ⅲ型偏Ⅱ₂型干酪根为主,含少量Ⅰ、Ⅱ₁型干酪根。哈尔加乌组泥岩主要以Ⅱ₂、Ⅲ型干酪根为主,巴塔玛依内山组泥岩主要以Ⅲ型干酪根为主。三塘湖盆地上石炭统烃源岩已经进入了成熟阶段的早、中期,少量样品热演化程度达到生油-湿气阶段。巴塔玛依内山组泥岩热成熟度要高于卡拉岗组和哈尔加乌组。三塘湖盆地剖面泥岩样品主要为差—一般烃源岩。姜巴斯套组烃源岩好于巴塔玛依内山组,哈尔加乌组烃源岩相对最差。三塘湖盆地石炭系岩心有机地球化学特征研究表明,上石炭统的沉积环境为淡水环境,并且呈现水体深浅不同的特征。地表样品有机地球化学特征研究表明,三塘湖盆地伊吾、纸房、大黑山等5个剖面及岩体一侧五个样品,其有机质形成的古环境为咸水还原环境,有机质输入以藻类等低水生生物和细菌为主,岩心样品的有机质类型为Ⅱ型～Ⅲ型,即含腐泥的腐殖型或腐殖型,而剖面样品主要为腐泥型。从多种生物标志化合物参数显示的结果来看,石炭系剖面样品的古沉积环境为咸化深水条件下的还原环境;有机质类型为腐泥型（海相藻类Ⅱ型～Ⅰ型）,有机质输入以藻类等水生生物为主,细菌有机质和少量的陆源物质也具有一定的贡献;有机质的演化程度总体为过成熟。中晚期海西构造运动以来构造—热事件对石炭系烃源岩的熟化起到了积极的作用。岩浆活动使地温梯度升高,促进了该区石炭系烃源岩快速达到成熟阶段,有利于烃类的形成。另一方面,火山-岩浆活动带来了丰富的地幔物质,这些物质的加入对有机质生烃演化起到了明显的催化作用,促进了烃类的形成。通过分析辉绿岩岩体一侧不同距离的烃源岩样品各项地球化学特征发现,该组烃源岩整体成熟度较高,同时靠近岩体1m～1.5m距离范围内,有机质的各项成熟度指标具有异常增高的趋势,说明侵入岩体与直接接触的烃源岩的烘烤作用的范围相对较小,大约在1.5m以内。更多还原

【Abstract】 Santanghu Basin,located in the northeast of Xinjiang Uighur Autonomous Region, bordering on Junggar basin to the west and Turpan-Hami Basin to the south,neighboring in Mongilia in northeast,the basin is generally NW-SE distributed.Santanghu Basin is a compound petroliferous basin with small areal extent,and it is formed by the superposition of various prototype basins from different age in tectonic evolution,which is in the south margin of Siberia Plate,south to Kazakhstan- Junggar Plate.The basin is located in the joint between the Kazakhstanian Plate and the Siberian Plate,situated between the Altai and Kelamaili structural belt,overlain the Paleozoic orogenic belt,and its tectonic position results in a complex tectonic evolutionary history for the basin.On the basis of the study in sedimentary thickness of the Carboniferous clastic rock,we mainly do some research on the Batamayineishan（C₂b）,the Haerjiawu（C₂h） and the Kalagang Formation（C₂k） of the Upper Carboniferous from the Santanghu area.It is inferred that the Haerjiawu Formation（C₂h） is the primary sedimentary period for the Upper Carboniferous mudstone,and it is the primary source rocks as well.Among all of them,the mudstone of the Haerjiawu mostly is well or perfect source rocks,and the mudstone of Kalagang is generally kerogen typeⅡ₂-Ⅲ,dominated by typeⅡ₂,contained a little kerogen typeⅠandⅡ₁.That of the Haerjiawu is mainly kerogen typeⅡ₂ orⅢ,and that of the Batamayineishan is mainly kerogen typeⅢ.The Upper Carboniferous source rocks in Santanghu are in the early or middle of maturity;A few samples reach the stage of hydrocarbon-humid gas generation as to thermal evolution degree.The thermal maturity of mudstone from Batamayineishan is higher than that of the Kalagang and Haerjiawu Formation.The mudstone samples from Santanghu section are mainly poor or general source rocks.Source rocks from the Jiangbasitao Formation are better than that of the Batamayineishan,and the Haerjiawu are the poorest in all of them.According to the geochemical characteristics of soluble organic matter of core samples from the Carboniferous source rocks in Santanghu basin,it is concluded that the Upper Carboniferous was deposited under fresh water environment,and characterized by different deep or shallow water.Based on the geochemical characteristics of soluble organic matter from surface samples,five sections included Yiwu,Zhifang,Daheishan and samples in the basin,it is inferred that the organic matter were formed under salt water reducing environment,organic matter was mainly from lower hydrobiont such as algae and bacteria, the soluble organic matter of core samples in the basin are generally typeⅡ-Ⅲ,that is sapropel-humic or humic type,while section samples are mainly sapropel in type.As far as various biomarker parameters concerned,section samples of the Carboniferous were deposited under a reducing environment with salty deep water,organic matter was sapropel type（marine algae typeⅡ-Ⅰtype）,and which was mainly derived from hydrobiont such as algae,include a little bacteria and terrigenous matters;Organic matter was high mature in evolution as a whole.The tectonic-thermal event since Hercynian Movement was positive for the maturity of the Carboniferous source rocks,magmatic activity increased geothermal gradient,and promoted the Carboniferous source rocks in the area being mature quickly,all of which were made for the formation of hydrocarbon.Additionally,volcano-magmatic activities brought abundant mantle matters,and these matters played a significant role in promoting hydrocarbon generation and evolution.The geochemical characteristic of the source rock samples from the side of diabase in different distance revealed high maturity of this group of source rocks,and the maturity parameters of organic matters increased abnormally in the range of 1m-1.5m distance to the rock,which show that the bake range of intrusive body and its direct contact source rocks was quite small,range in 1.5m.更多还原