本文選題：尼瑪盆地 + 烴源巖�。� 參考：《成都理工大學》2017年碩士論文

【摘要】：尼瑪盆地位于西藏中部,是一個新生代陸相盆地。與之毗鄰的倫坡拉盆地是目前西藏唯一獲得工業(yè)油流的沉積盆地。近年油氣顯示的發(fā)現(xiàn)表明尼瑪盆地是一個含油氣盆地。古近系牛堡組和丁青湖組被認為是最有可能發(fā)育有效烴源巖的層位,目前對于這套烴源巖的研究集中于傳統(tǒng)的烴源巖評價,而沉積學特征卻鮮有涉及。本文以沉積學、石油地質(zhì)學為理論指導,應(yīng)用巖相分析、有機地球化學和有機巖石學方法,對尼瑪盆地古近系烴源巖進行了系統(tǒng)的沉積學研究和烴源巖綜合評價,并結(jié)合兩者初步討論了尼瑪盆地湖相烴源巖的控制因素。取得了如下認識:在尼瑪盆地實測古近系地層剖面中劃分出17中主要的巖相類型,可歸納為7種巖相序列。利用巖相組合特征對各個剖面進行沉積相分析,結(jié)果如下:新禿那若剖面識別出湖泊相與扇三角洲沉積相;蝦別錯剖面識別出扇三角洲相;朗弄巴剖面識別出三角洲相與湖泊相兩種沉積相;查昂巴剖面識別出湖泊相;尼1井剖面識別出三角洲相和湖泊相兩種沉積相。牛堡組烴源巖有機質(zhì)豐度較高,大多數(shù)樣品的TOC0.4%,其中泥質(zhì)烴源巖的TOC明顯高于灰?guī)r烴源巖,有機質(zhì)類型以Ⅱ1為主,樣品成熟度以低成熟和成熟為主。丁青湖組烴源巖雖然TOC含量很高,平均值達到了5.06%,但有機質(zhì)類型以Ⅱ2或者Ⅲ型為主,且樣品成熟度偏低,以低成熟和未成熟為主。綜合評價表明,牛堡組烴源巖生烴條件優(yōu)于丁青湖組,丁青湖組烴源巖品質(zhì)的關(guān)鍵限制因素是成熟度偏低。查昂巴地區(qū)的牛堡組泥質(zhì)烴源巖厚度大,生烴條件好,應(yīng)是油氣勘探的重點關(guān)注區(qū)域。尼瑪盆地古近系沉積相分布控制了烴源巖的發(fā)育情況,北部坳陷地區(qū)水體淺,發(fā)育扇三角洲平原與干鹽湖相沉積,烴源巖品質(zhì)并不是很好,并且有機質(zhì)成熟度普遍偏低,很多樣品的有機質(zhì)成熟度并沒有到達生烴門限。南部坳陷水體深度大于北部坳陷,湖湘沉積更為發(fā)育。其西部干鹽湖地區(qū)的烴源巖樣品品質(zhì)較差,中東部地區(qū)深湖相烴源巖品質(zhì)明顯變好。此外,CPI與TOC、姥植比與CPI、姥植比與TOC之間存在著相關(guān)性,尼瑪盆地古湖盆可能受到高鹽度的影響,生產(chǎn)力較為低下,高等植物輸入量在很大程度上控制了有機質(zhì)的豐度,這造成了盆地內(nèi)的烴源巖有機質(zhì)類型普遍是混合型的�？傮w而言,尼瑪盆地形成具有一定厚度高有機質(zhì)豐度烴源巖的可能性較小。
[Abstract]:The Nima basin, located in central Tibet, is a Cenozoic continental basin. The Lunpola basin is the only sedimentary basin with industrial oil flow in Tibet. The discovery of oil and gas in recent years indicates that the Nima Basin is an oil and gas bearing basin. Paleogene Niupu formation and Dingqinghu formation are considered to be the most likely horizons for the development of effective source rocks. At present, the research on this set of source rocks is focused on traditional source rock evaluation, but the sedimentological characteristics are seldom involved. Based on the theory of sedimentology and petroleum geology and the application of lithofacies analysis, organic geochemistry and organic petrology, a systematic sedimentological study and a comprehensive evaluation of the source rocks of Paleogene in the Nima Basin have been carried out in this paper. The controlling factors of lacustrine source rocks in Nima Basin are discussed. The main lithofacies types in the Paleogene stratigraphic profile of the Nima Basin can be divided into 7 lithofacies sequences. The sedimentary facies of each section are analyzed by using the characteristics of lithofacies assemblage. The results are as follows: the lacustrine facies and fan delta sedimentary facies are identified in the Xinbalanaro section, the fan delta facies are identified in the Shrimp fault section; Two sedimentary facies, delta facies and lacustrine facies, are identified in Langomba section, Chaumba section and Nei 1 section respectively. The abundance of organic matter in source rocks of Niubu formation is relatively high, and the TOC 0.4 of most samples is high. The TOC of argillaceous source rocks is obviously higher than that of limestone source rocks, and the type of organic matter is mainly 鈪，

本文編號：1930307