A Novel Approach for Quantitative Study on Two-source-mixed Natural Gas Reservoirs
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摘要: 确定端元气混合比例是混源气定量研究的主要内容。以两元混合天然气为例,首先要分析混源成藏的地质条件,以确定可能的气源岩;然后根据源岩生气模拟实验与实测数据,建立端元气与混源气的地球化学模型,确定混源气的混合比例与源岩成熟度;最后将结果用于混源成藏过程分析,提出混源成藏的地球化学机制。鄂尔多斯盆地中部奥陶系风化壳天然气为上古生界煤成气和下古生界油型气混源气。从混源气藏形成的地质条件和地质过程着手,利用天然气中甲、乙烷百分组成和碳同位素组成,建立了混合比例估算模型,并绘制了估算图版。对靖边等气田13个天然气样品进行研究,发现混源气混合比变化很大。除去全为煤成气(陕21井)和全为油型气(陕5井)的两个样品之外,11个样品上古生界煤成气和下古生界油型气比例分布分别为22%～84%和16%～78%。但总体以下古生界油型气为主,平均所占比例63.2%,说明鄂尔多斯盆地中部奥陶系风化壳天然气以下古生界自生油型气为主。Abstract: Calculating ratio of source-mixed natural gas is important in study ing source-mixed gas reservoir. For a two-source-mixed gas reservoir, the follow ing w orkmust be done: (1) analyzing the geological factors of formation of source-mixed gas reservoir, confirm ing potential source rocks, (2) based on experimental data of ascertained source rocks andmeasured data of natural gas, f ind ing geochemical modes of different end-gas and source-mixed gas, then using themodes to calculate ratios of source-mixed gas andmaturity of source rocks, (3) using the ratios to analyze the format ion process of source-mixed gas reservoir, proposing geochemical trappingmechanism. The natural gas in Ordovician weathering crust reservoir in the Central Portion Gas Field in Ordos basin is source-m ixed gas of Upper Paleozoic coal-typed gas with Lower Paleozoic oil-typed gas. Starting w ith analyzing geoloical factors and process of the source-mixed reservoir, with geochemical parameters of percentages and carbon isotope composit ions of methane and ethane, a calculating model of rat ios w as established and a calcu lating graph of ratios was given in this paper. 13 gas samples collected from Jianbian gas field were analyzed using the method. The percentages of Upper Paleozo ic coal-typed gas and Lower Paleozoic oil-typed gas are 22~ 84 percent and 16~ 78 percen,t respective ly, according to 11 samples ( samples collected from Well Shan21 and Shan5 were excluded). Based on the result, we could draw a conclusion that Lower Paleozoic oil-typed gas, with the percentage of 63.2, is dom inant in Ordovician weathering crust reservoir in the Centra lPotion gas field in Ordos basin
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[1] 1 金强,程付启,刘文汇. 混源气藏及混源比例研究[J].天然气工业,2004,(02):22-24.
2 Faber E,Stahl W. Geochemical surface exploration for hydrocarbons in the North Sea[J].AAPG Bulletin,1984.363-368.
3 Berner U,Faber E. Maturity related mixing model for methane,ethane and propane,based on carbon isotopes[J].Advances in Organic Geochemistry,1988.67-72.
4 戴金星. 天然气碳氢同位素的特征和各类天然气的识别[J].天然气地球科学,1993,(2-3):1-40.
5 张义纲,章复康,郑朝阳. 识别天然气的碳同位素方法[A].北京:地质出版社,1987.1-14.
6 戴金星,裴锡古,戚厚发. 中国天然气地质学[M].北京:石油工业出版社,1992.
7 高先志. 利用甲烷碳同位素研究混合气的混合体积[J].沉积学报,1997,(02):63-65.
8 王顺玉,戴鸿鸣,王海清. 混源天然气定量计算方法-以川西白马庙气田为例[J].天然气地球科学,2003,(05):351-353.
9 陈安定. 陕甘宁盆地奥陶系源岩及碳酸盐岩生烃的有关问题讨论[J].沉积学报,1996,(ZK):90-99.
10 陈安定. 论鄂尔多斯盆地中部气田混合气的实质[J].石油勘探与开发,2002,(02):33-38.
11 孙冬敏,秦胜飞,李先奇. 鄂尔多斯盆地奥陶系风化壳产层天然气来源分析[A].北京:石油工业出版社,1997.46-54.
12 郝石生,高耀斌,黄志龙. 鄂尔多斯中部大气田聚集条件及运聚动平衡[J].中国科学D辑,1996,(06):488-492.
13 关德师,张文正,裴戈. 鄂尔多斯盆地中部气田奥陶系产层的油气源[J].石油与天然气地质,1993,(03):191-199.
14 Schoell M. The hydrogen and carbon isotopic compositions of methane from natural gases of various origins[J].Geochimica et Cosmochimica Acta,1980,(05):649-661.
15 沈平,徐永昌,王先彬. 气源岩和天然气地球化学特征及成气机理研究[M].兰州:甘肃科学技术出版社,1991.1-243.
16 Berner U,Faber E. Empirical carbon isotope/maturity relationships for gases from algal kerogens and terrigenous organic matter,based on dry,open-system pyrolysis[J].Organic Geochemistry,1996,(10):947-955.
17 刘文汇,宋岩,刘全有. 煤岩及其主显微组份热解气碳同位素组成的演化[J].沉积学报,2003,(01):183-190.
18 夏新宇,赵林,曾凡刚. 鄂尔多斯盆地中部气田奥陶系风化壳气藏天然气来源及混源比计算[J].沉积学报,1998,(03):75-79.
19 Jenden P D,Drazan D J,Kaplan I R. Mixing of thermogenic natural gases in northern Appalachian basin[J].AAPG Bulletin,1993,(06):980-998. -
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