节点文献
柴达木盆地天然气的碳同位素地球化学特征及成因分析
Characteristics of Carbon Isotope and Origin of Natural Gas in Qaidam Basin
【摘要】 依据天然气碳同位素中δ13C1、δ13C2、δ13C3的组成与划分标准,将柴达木盆地天然气划分为煤型气、裂解气、油型气与生物气四种类型,通过对天然气同位素中的1δ3C1、1δ3C2-1δ3C1、δ13C3-1δ3C2值的差异分析以及与对应的烃源岩干酪根碳同位素进行对比分析,探讨了柴达木盆地不同地区天然气的成因以及影响因素,这对于探索柴达木盆地的成气规律以及在不同地区天然气勘探的目标选择都有着现实意义。
【Abstract】 δ13C1,δ13C2,δ13C3,δ13C4ofnatural gas isotopic composition are various in different parts of Qaidam Basin.The averageof them are-23.1‰,-24.1‰,-22.7‰ and-23.6‰ in Sanhu area around;-29.8‰,-24.7‰,-23.1‰ and-22.9‰ in Chaibeiyuan area;-39.2‰,-26.8‰,-23‰ and-23‰ in Chaixi area;-67.8‰,-39.2‰,-32.3‰ and lack ofδ13C4in Sanhu area.δ13C4>δ13C3>δ13C2>δ13C1exist betweencomponent of most naturalgas isotope,and reversionof minor heavy carbon isotopic composition exist.Reginally,δ13C1,δ13C2,δ13C3,δ13C4ofnatural gas isotopic compositiondecrease gradually fromSanhu area around,Chaibeiyuan area and Chaixi area to Sanhu area.δ13C2-δ13C1andδ13C3-δ13C2 ofnatural gas isotopic composition increase gradually fromSanhu area around,Chaibeiyuan area and Chaixi area to Sanhu area,the averageof them are-0.8‰ and-0.9‰ inSanhu area around,5.1‰ and 1.3‰ in Chaibeiyuan area,14.5‰ and 2.3‰ in Chaixi area,27.9‰ and 12.5‰ in Sanhu area. δ13C4>δ13C3>δ13C2>δ13C1exist betweencomponent of most naturalgas isotope because naturalgas of organic geneses are derived from the similar process of thermodynamic action,and reversionof minor heavy carbon isotopic composition exist because of the mixed action of natural gas from the different derivation or the difference of duration,temperatures and pressuresin developing hydrocarbon process from the same source rock.The difference between δ13C2-δ13C1and δ13C3-δ13C2in different area depend on duration,temperatures and pressuresof source rock evolution,the higher temperatures and pressuresand the longer duration of source rock evolution,the more uniformδ13C distribution between naturalgas component.In the meantime,bacteria and types of kerogen have an effect on δ13C2-δ13C1andδ13C3-δ13C2to some extent.The study on carbon isotope geochemical characteristic.can not only divide types of naturalgas and discusstheir geneses in theory,but also guide the exploration of naturalgas.
- 【文献出处】 沉积学报 ,Acta Sedimentologica Sinica , 编辑部邮箱 ,2006年01期
- 【分类号】P618.13;P597
- 【被引频次】17
- 【下载频次】590