通过对志丹-甘泉地区天然气样品的组分、稳定碳氢同位素的测定,综合分析、对比认为:①鄂尔多斯盆地志丹-甘泉地区天然气主要组分甲烷的稳定碳同位素主要分布在-32‰≤δ13 C 1≤-25‰范围内,乙烷的稳定碳同位素主要分布在-38‰≤δ13 C ...通过对志丹-甘泉地区天然气样品的组分、稳定碳氢同位素的测定,综合分析、对比认为:①鄂尔多斯盆地志丹-甘泉地区天然气主要组分甲烷的稳定碳同位素主要分布在-32‰≤δ13 C 1≤-25‰范围内,乙烷的稳定碳同位素主要分布在-38‰≤δ13 C 2≤-24‰范围内,天然气甲烷氢同位素主要分布在-170‰≤δ2D 1≤-160‰内;②研究区碳氢同位素相比北部苏里格气田偏重,天然气类型主要为煤系烃源岩Ⅲ型干酪根初次裂解气,同时混有少量液态烃的二次裂解气;该区天然气已发生明显的次生变化,但是扩散运移和外部气源的混入都可以使测试样品发生碳同位素的斜率的倒转;③运移分馏是造成该区天然气产生碳同位素倒转和次生变化的主要原因之一。以上成果认识对研究区天然气地球化学特征研究具有重要指导作用,对类似盆地天然气地球化学特征研究具有一定借鉴价值。展开更多
玛湖凹陷风城组是目前中国已知最古老的碱湖沉积,发育优质湖相烃源岩。来自风城组的烃源岩作为准噶尔盆地油气生成的物质基础发挥了至关重要的作用。为了解该套烃源岩的生烃演化特征,应用WYMN-3型高温高压半封闭模拟实验平台对采自玛湖...玛湖凹陷风城组是目前中国已知最古老的碱湖沉积,发育优质湖相烃源岩。来自风城组的烃源岩作为准噶尔盆地油气生成的物质基础发挥了至关重要的作用。为了解该套烃源岩的生烃演化特征,应用WYMN-3型高温高压半封闭模拟实验平台对采自玛湖凹陷玛页1井风城组的烃源岩样品进行生烃模拟实验,获取生油、生气及其气体碳同位素参数,分析其生烃演化过程。结果表明:风城组风二段(P 1 f 2)泥岩在受热演化过程中以生油为主,生气为辅。在350℃时为排出油、残留油产率的高峰,分别为325.35、239.45 mg/gTOC,在高温阶段(400~500℃)仍然存在生油潜力。气态烃在375℃以后开始逐渐产出,烃类气体的来源主要为油的二次裂解。烃类气体的碳同位素序列未出现倒转现象。但在低温阶段出现了翻转现象,350℃为转折点,也是生油高峰的温度点。根据烃类产率特征、气态烃碳同位素组成以及烃类气体异构比特征可将风城组烃源岩的演化生烃过程划分为4个阶段,即干酪根最初裂解→干酪根裂解→油裂解→油气裂解。展开更多
Based on analyses of the components of crude oil hydrocarbons and carbon isotopes,the content of normal alkane decreased from 49.00% to 20.10% when moving from the No.3 to No.5 tectonic belt of the Lenghu area of the ...Based on analyses of the components of crude oil hydrocarbons and carbon isotopes,the content of normal alkane decreased from 49.00% to 20.10% when moving from the No.3 to No.5 tectonic belt of the Lenghu area of the Qaidam Basin,while cycloalkanes increased from 30.00% to 52.20% and aromatic and branch chain alkanes increased gradually as well. The maturity of sterane in crude oil is higher than that of its source-rock,which shows that the hydrocarbons were generated from a deep source-rock of high maturity around the tectonic belts of the Lenghu area. The analysis of the characteristics of carbon isotopes also shows that these isotopes of hydrocarbon compounds in the No.4 and No.5 tectonic belt are apparently heavier than those in the No.3 belt. The results of our research show that the hydrocarbons in the No.3 tectonic belt are mainly from a relatively rich sapropelic substance,while the hydrocarbons in the No.4 and No.5 tectonic belt originated mainly from organic matter of a relatively rich humic type substance.展开更多
Speleothem carbonates are precipitated continuously from inorganic carbon dissolved in seepage water infiltrating from the land surface,that reflects a mixture of atmospheric CO_2,respired soil carbon,and epikarst sou...Speleothem carbonates are precipitated continuously from inorganic carbon dissolved in seepage water infiltrating from the land surface,that reflects a mixture of atmospheric CO_2,respired soil carbon,and epikarst sources,each with distinct δ^(13)C values.To aid in deconvolving these signatures,soil samples were collected above the Blue Spring cave system in Sparta,Tennessee,USA and subjected to a series of incubation experiments,in order to constrain the correlation between CO_2respiration rates and soil moisture.This relationship is used to parameterize a simple mixing model which predicts the relationship between δ^(13)C and soil moisture in fluids infiltrating into the underlying cave system.展开更多
To understand the effects of leaf physiological and morphological characteristics on δ13C of alpine trees, we examined leaf δ13C value, LA, SD, LNC, LPC, LKC, Chla+b, LDMC, LMA and Narea in one-year-old needles of P...To understand the effects of leaf physiological and morphological characteristics on δ13C of alpine trees, we examined leaf δ13C value, LA, SD, LNC, LPC, LKC, Chla+b, LDMC, LMA and Narea in one-year-old needles of Picea schrenkiana var. tianschanica at ten points along an altitudinal gradient from 1420 m to 2300 m a.s.l. on the northern slopes of the Tianshan Mountains in northwest China. Our results indicated that all the leaf traits differed significantly among sampling sites along the altitudinal gradient(P<0.001). LA, SD, LPC, LKC increased linearly with increasing elevation, whereas leaf δ13C, LNC, Chla+b, LDMC, LMA and Narea varied non-linearly with changes in altitude. Stepwise multiple regression analyses showed that four controlled physiological and morphological characteristics influenced the variation of δ13C. Among these four controlled factors, LKC was the most profound physiological factor that affected δ13C values, LA was the secondary morphological factor, SD was the third morphological factor, LNC was the last physiological factor. This suggested that leaf δ13C was directly controlled by physiological and morphological adjustments with changing environmental conditions due to the elevation.展开更多
文摘通过对志丹-甘泉地区天然气样品的组分、稳定碳氢同位素的测定,综合分析、对比认为:①鄂尔多斯盆地志丹-甘泉地区天然气主要组分甲烷的稳定碳同位素主要分布在-32‰≤δ13 C 1≤-25‰范围内,乙烷的稳定碳同位素主要分布在-38‰≤δ13 C 2≤-24‰范围内,天然气甲烷氢同位素主要分布在-170‰≤δ2D 1≤-160‰内;②研究区碳氢同位素相比北部苏里格气田偏重,天然气类型主要为煤系烃源岩Ⅲ型干酪根初次裂解气,同时混有少量液态烃的二次裂解气;该区天然气已发生明显的次生变化,但是扩散运移和外部气源的混入都可以使测试样品发生碳同位素的斜率的倒转;③运移分馏是造成该区天然气产生碳同位素倒转和次生变化的主要原因之一。以上成果认识对研究区天然气地球化学特征研究具有重要指导作用,对类似盆地天然气地球化学特征研究具有一定借鉴价值。
文摘玛湖凹陷风城组是目前中国已知最古老的碱湖沉积,发育优质湖相烃源岩。来自风城组的烃源岩作为准噶尔盆地油气生成的物质基础发挥了至关重要的作用。为了解该套烃源岩的生烃演化特征,应用WYMN-3型高温高压半封闭模拟实验平台对采自玛湖凹陷玛页1井风城组的烃源岩样品进行生烃模拟实验,获取生油、生气及其气体碳同位素参数,分析其生烃演化过程。结果表明:风城组风二段(P 1 f 2)泥岩在受热演化过程中以生油为主,生气为辅。在350℃时为排出油、残留油产率的高峰,分别为325.35、239.45 mg/gTOC,在高温阶段(400~500℃)仍然存在生油潜力。气态烃在375℃以后开始逐渐产出,烃类气体的来源主要为油的二次裂解。烃类气体的碳同位素序列未出现倒转现象。但在低温阶段出现了翻转现象,350℃为转折点,也是生油高峰的温度点。根据烃类产率特征、气态烃碳同位素组成以及烃类气体异构比特征可将风城组烃源岩的演化生烃过程划分为4个阶段,即干酪根最初裂解→干酪根裂解→油裂解→油气裂解。
基金Project 2009011 supported by the Resource Exploration Projects of the Ministry of Land and Resources of Chinathe State Key Laboratory of Petroleum Resource and Prospecting of China Petroleum University (Beijing)
文摘Based on analyses of the components of crude oil hydrocarbons and carbon isotopes,the content of normal alkane decreased from 49.00% to 20.10% when moving from the No.3 to No.5 tectonic belt of the Lenghu area of the Qaidam Basin,while cycloalkanes increased from 30.00% to 52.20% and aromatic and branch chain alkanes increased gradually as well. The maturity of sterane in crude oil is higher than that of its source-rock,which shows that the hydrocarbons were generated from a deep source-rock of high maturity around the tectonic belts of the Lenghu area. The analysis of the characteristics of carbon isotopes also shows that these isotopes of hydrocarbon compounds in the No.4 and No.5 tectonic belt are apparently heavier than those in the No.3 belt. The results of our research show that the hydrocarbons in the No.3 tectonic belt are mainly from a relatively rich sapropelic substance,while the hydrocarbons in the No.4 and No.5 tectonic belt originated mainly from organic matter of a relatively rich humic type substance.
基金supported by the US National Science Foundation, project EAR-1600931
文摘Speleothem carbonates are precipitated continuously from inorganic carbon dissolved in seepage water infiltrating from the land surface,that reflects a mixture of atmospheric CO_2,respired soil carbon,and epikarst sources,each with distinct δ^(13)C values.To aid in deconvolving these signatures,soil samples were collected above the Blue Spring cave system in Sparta,Tennessee,USA and subjected to a series of incubation experiments,in order to constrain the correlation between CO_2respiration rates and soil moisture.This relationship is used to parameterize a simple mixing model which predicts the relationship between δ^(13)C and soil moisture in fluids infiltrating into the underlying cave system.
基金supported by the Major Research Plan of the National Natural Science Foundation of China (Grant No. Y411381001)the National Natural Science Foundation of China (Grant No. 91125025)the Postdoctoral Science Foundation of China (Grant No. 2013M532096)
文摘To understand the effects of leaf physiological and morphological characteristics on δ13C of alpine trees, we examined leaf δ13C value, LA, SD, LNC, LPC, LKC, Chla+b, LDMC, LMA and Narea in one-year-old needles of Picea schrenkiana var. tianschanica at ten points along an altitudinal gradient from 1420 m to 2300 m a.s.l. on the northern slopes of the Tianshan Mountains in northwest China. Our results indicated that all the leaf traits differed significantly among sampling sites along the altitudinal gradient(P<0.001). LA, SD, LPC, LKC increased linearly with increasing elevation, whereas leaf δ13C, LNC, Chla+b, LDMC, LMA and Narea varied non-linearly with changes in altitude. Stepwise multiple regression analyses showed that four controlled physiological and morphological characteristics influenced the variation of δ13C. Among these four controlled factors, LKC was the most profound physiological factor that affected δ13C values, LA was the secondary morphological factor, SD was the third morphological factor, LNC was the last physiological factor. This suggested that leaf δ13C was directly controlled by physiological and morphological adjustments with changing environmental conditions due to the elevation.
