西澳大利亚珀斯盆地页岩气资源研究     

杨恺  李华 《中国煤炭地质》2014,(12):48-53

珀斯盆地位于澳大利亚西海岸,是西澳大利亚页岩气资源勘探的重点区域。该盆地属于复杂的凹陷裂谷,海相沉积二叠纪的Carynginia组和早三叠世Kockatea页岩层被认为是潜在的含气地层。通过搜集大量外文文献,全面总结了该盆地含气目标层的地物化特征,Carynginia组的总有机碳含量为1%~15%,干酪根为III型,Ro在0.56~1.91;Kockatea页岩层的总有机碳含量为1%~4%,干酪根为II/III混合型,Ro为0.48~1.93。两组共划分了11各岩相段,其中黑色页岩岩相段和含黄铁矿泥岩段是最重要的生烃含气层。综合考虑地层、地化指标和岩石地球物理性质,圈出了可供参考的页岩气甜点区。  相似文献   

Genesis and organic geochemical characteristics of the carbonaceous rock stratabound gold deposits, South China     

HU Kai  ZHAI Jianping  LIU Yingjun  WANG Henian  ZHANG Jingrong  JIA Rongfen 《中国科学D辑(英文版)》2000,43(5):507-520

The organic matter of three different chronological major carbonaceous rock gold-bearing formations of South China (Middle Proterozoic Shangqiaoshan group of northeastern Jiangxi, Lower Cambrian Shuikou group of northern Guangxi and Devonian Shetianqiao group of eastern Hunan) and related carbonaceous stratabound gold deposits such as Jinshan, Longshui and Shixia deposits, respectively, has been characterized by organic geochemical techniques. These organic geochemical results show that the average total organic carbon (TOC) content of the three chronological carbonaceous rock gold-bearing formations of South China ranges from 0.15% to 1.56%. The thermal maturity of the organic matter of host rocks in the three gold-bearing formations is high. The micro-component of the organic matter of the host rocks consists primarily of solid bitumen and graphite. The organic carbon and gold of the host rocks appear to syndepositin situ during the formation of the gold-bearing formations. The organic carbon played a certain role in controlling the geochemical environment of the gold-bearing formations. The metallogenetic mechanism of the carbonaceous rock stratabound gold deposits of South China is closely associated in genesis with the sedimentation, diagenesis and thermal evolution history of the organic matter of host rocks in the gold-bearing formations.  相似文献   

Free fatty acid analysis of the early proterozoic animikie group,Minnesota and Ontario     

J.S. Janks  R.M. Matherly  A.F. Koster van Groos 《Organic Geochemistry》1985,8(3):215-219

The Early Proterozoic iron formation-slate sequences of the Animikie Group have been analyzed for fatty acids and the results discussed in light of the regional metamorphic history and kerogen H/C and N/C atomic ratios. No fatty acids, free or inorganically bound, were detected. The highest H/C ratios are found in the Gunflint (mean = 0.57) and lowest in the Virginia State (0.19). The lower H/C ratio in the Biwabik (mean = 0.45) is interpreted as a function of higher metamorphic grade in that iron formation. The absence of fatty acids is attributed to dehydrogenation and cyclization of the original material to the present H/C ratio of about 0.5. The Gunflint Iron-Formation, which represents those conditions most likely to preserve chemical fossils in the Animikie Group has already exceeded minimum conditions for fatty acid preservation. Hydrogen to carbon ratios in pelitic rocks are consistently lower than their underlying iron-formation. It is suggested that sulfur and/or clay alter the kinetics of the dehydrogenation reaction, creating lower H/C ratios in the pelites.  相似文献   

On the chemical mechanism of kerogen thermal transformation. Study of the transformation of sporopollenin     

M.A. Bestougeff  R.J. Byramjee  B. Pesneau 《Organic Geochemistry》1985,8(6):389-398

Experiments were carried out on the thermal decomposition of sporopollenin, isolated from a marine algae (Lycopodium clavatum) at constant temperature (380°C) and pressure (around 200 atm), but for varying pyrolysis times.The decomposition products were separated into groups, analysed by chromatography and infra-red spectroscopy, and their elemental composition determined. The thermal evolution of sporopollenin proceeds in three distinct steps: first, a partial decomposition of the initial substance occurs with the formation of soluble materials. This is followed by a full decomposition of the sporopollenin and disappearance of the non-soluble residue. Finally, a non-soluble material reappears. It is proposed that, due to secondary reactions, the evolution of kerogen of the sapropelic type is similar to what has been observed in mild pyrolysis experiments.  相似文献   

Kerogen-mineral reactions at raised temperatures in the presence of water     

T.I. Eglinton  S.J. Rowland  C.D. Curtis  A.G. Douglas 《Organic Geochemistry》1986,10(4-6)

Kerogen has been artificially matured under “hydrous pyrolysis” conditions in the presence of various minerals in order to investigate the influence of the latter on the organic products. In addition to three clay minerals (montmorillonite, illite, kaolinite), calcium carbonate and limonite were also employed as inorganic substrates. Kerogen (Type II) isolated from the Kimmeridge Blackstone band was heated in the presence of water and a 20-fold excess of mineral phase at two different temperatures (280 and 330°C) for 72 hr. Control experiments were also carried out using kerogen and water only and kerogen under anhydrous conditions. This preliminary study describes the bulk composition of the pyrolysates with detailed analyses of the aliphatic hydrocarbon distributions being provided by gas chromatography and combined gas chromatography-mass spectrometry.In the 280°C experiments, considerably more organic-soluble pyrolysate (15% by weight of original kerogen) was produced when calcium carbonate was the inorganic phase. At 330°C, all samples generated much greater amounts of organic-soluble products with calcium carbonate again producing a large yield (40% wt/wt). Biomarker epimerisation reactions have also proceeded further in the 330°C pyrolysate formed in the presence of calcium carbonate than with other inorganic phases. Implications of these and other observations are discussed.  相似文献   

Long-chain carboxylic acids in pyrolysates of Green River kerogen     

Kimitaka Kawamura  Eu Tannenbaum  B.J. Huizinga  I.R. Kaplan 《Organic Geochemistry》1986,10(4-6)

Long-chain fatty acids (C₁₀-C₃₂), as well as C₁₄-C21 isoprenoid acids (except for C₁₈), have been identified in anhydrous and hydrous pyrolyses products of Green River kerogen (200–400°C, 2–1000 hr). These kerogen-released fatty acids are characterized by a strong even/odd predominance (CPI: 4.8-10.2) with a maximum at C₁₆ followed by lesser amounts of C₁₈ and C₂₂ acids. This distribution is different from that of unbound and bound geolipids extracted from Green River shale. The unbound fatty acids show a weak even/odd predominance (CPI: 1.64) with a maximum at C₁₄, and bound fatty acids display an even/odd predominance (CPI: 2.8) with maxima at C₁₈ and C₃₀. These results suggest that fatty acids were incorporated into kerogen during sedimentation and early diagenesis and were protected from microbial and chemical changes over geological periods of time. Total quantities of fatty acids produced during heating of the kerogen ranged from 0.71 to 3.2 mg/g kerogen. Highest concentrations were obtained when kerogen was heated with water for 100 hr at 300°C. Generally, their amounts did not decrease under hydrous conditions with increase in temperature or heating time, suggesting that significant decarboxylation did not occur under the pyrolysis conditions used, although hydrocarbons were extensively generated.  相似文献   

The formation, and clay mineral and CaCO₃ association reactions of melanoidins     

K. Taguchi  Y. Sampei 《Organic Geochemistry》1986,10(4-6)

Melanoidin syntheses, which are carried out by preparing aqueous solutions of glucose and glycine, and glucose and alanine are examined with respect to variation of concentration of reactants, hydrogen ion concentration, molecular weights, functional groups and elemental compositions with increasing heating time at constant temperature (90°C). The experiments reveal that “melanoidins” consist of a mixture of fulvic acid-, humic acid- and kerogen-like polymers, with the initial formation of fulvic acid-, followed by humic acid- and kerogen-like polymers, but showing a period of coexistence of humic acid- and kerogen-like polymers. The kerogen-like polymers have elemental compositions similar to type II or II/III kerogens. The rate of melanoidin formation is much higher in the presence of montmorillonite. The CaCO₃ association reactions of the same experiments, however, show extremely low rates of melanoidin formation. Laboratory simulations seem to be consistent with the observation that carbonate sediments usually contain small amounts of kerogens compared with clayey sediments, both Recent and ancient.  相似文献   

四川石棉田湾金矿床中原生型和迁移型有机质及其成矿意义     

胡明安  杨铸生  贺金良 《地质科技情报》1999,18(1):18-59

四川石棉田湾金矿床中含有原生型干酪根和迁移型有机流体,在成矿期间由于含矿热液的改造,原生有机质发生热降解,生成小分子有机化合物,构成容易迁移的有机流体。同时,地表下渗的大气降水携带了细菌类微生物,对原生有机质进行生物降解,并生成硫化氢类还原物质。当含矿热液与有机流体及硫化氢混合时,促使矿液中金络合物被破坏,导致自然金的沉淀富集。  相似文献   

Prognostication of hydrocarbon generative potential in the onshore and offshore Niger Delta,Nigeria using TOC content and rock-eval pyrolysis techniques     

E. K. Nyantakyi  Tao Li  Wangshui Hu  J. K. Borkloe  R. D. Nagre 《中国地球化学学报》2014,33(2):138-144

This article prognosticates the hydrocarbon generation potential of core samples from fields A, B, C and D in Niger delta, Nigeria. The objectives of this study are to characterize the quality of these core samples by organic geochemical analyses. A total of ten core samples collected from fields A, B, C and D in Niger delta were analyzed using total organic carbon （TOC） content analysis, rock-eval pyrolysis technique. The analytical results of the stud- ied core samples reveal that they have generally high total organic carbon contents （TOC）, suggesting that conditions in the Niger delta favour organic matter production and preservation. There is a variation in the kerogen types and this may be attributed to the relative stratigraphic positions of the core samples within the Niger delta. The rock-eval results indicate that the samples from fields C and D contain predominantly Type II kerogen with a capacity to gen- erate oil and gas and hence have good generative potential. The samples from fields A and B contain mainly Type III kerogen and are gas-prone with moderate generative potential.  相似文献   

西藏南羌塘盆地侏罗系烃源岩地球化学特征   总被引：4，自引：1，他引：3  

陈文彬  廖忠礼  刘建清  付修根  杜佰伟  冯兴雷  杜秋定 《现代地质》2010,24(4)

依据剖面露头样品的实验测试资料,通过Rock-Eval岩石评价、显微镜下观察、镜质体反射率、烃源岩可溶有机质特征、单体烃碳同位素等分析方法,对南羌塘盆地侏罗系烃源岩地球化学特征进行综合研究。研究结果表明:南羌塘盆地侏罗系烃源岩有机质丰度较低,总体上夏里组泥质烃源岩要好于布曲组和索瓦组碳酸盐岩烃源岩;烃源岩的有机质类型较好,主要为Ⅱ1型,并且反映出烃源岩形成于具一定盐度的较强还原环境,其有机质以海相低等水生生物为主;烃源岩的热演化程度总体较高,达到高成熟阶段。正构烷烃单体烃碳同位素分析表明,侏罗系各组烃源岩之间在母质输入上可能存在较大差异,该地区白云岩油苗与夏里组泥质烃源岩有很强亲缘关系。  相似文献