首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 250 毫秒
1.
刘斌 《地球化学》1985,(1):90-97
Three thermodynamical equations, for unitary two-phase fluid inclusions have been deduced. (1) The thermodynamical equation for mutual transformation between gas and liquid phases in fluid inclusions. The transformation direction from one phase to the other can be known in terms of the density and filling degree of gas and liquid. (2) The thermodynamical equation for pressure effect on temperature after homogenization of fluid inclusions. The coefficient of P-T variation is directly proportional to the fining degree of gas phase and inversely to the density of gas phase and liquid phase. Equations for homogenization, decrepitation and formation temperatures of fluid inclusions can be inferred from. this equation. (3) The thermodynomical equation for decrepitation temperatures of fluid inclusions. Many factors have effects on the decrepitation temperatures of fluid inclusions.Decrepitation temperature cannot be considered in any case as formation temperature.Thermal and vapor halos produced by decrepitation of minerals of the same kind and the same period from the same locality are worthy of consideration.  相似文献   

2.
Presented in this paper are the rypes,salinities,homogenization temperatures and organic components of fluid inclusions formed at the four stages of diagenetic authigenesis in the Eogene of the Biyang Depression.The results of cooling experiments on fluid inclusions were used to determine the fluid system and composition of saline aqueous solution in each of the stages .The homogenization temperatures of saline aqueous solution inclusions and hydrocarbon organic inclu-sions have been corrected by two approaches ,and the trapping temperatures and pressures of fluid inclusions at each of the stages have been obtained.This strdy has shed light on the physicochemistry and evolution of diagenetic fluids.The diagentic fluid system is a system which was transformed from a chloride-bearing to a carbonate-bearing system along with the diagenic evolu-tion.The decrease of diagenetic temperature at Stage III of diagenetic authigenesis suggests that the depression would have experiences uplifting at that time.The fluorescent characteristics of fluid inclusions indicate the varieties of organic components in fluid inclusions both in time and in space.  相似文献   

3.
The acoustic decrepitation method heats a small monomineralic sample and counts pressure impulses as the inclusions burst when they develop high internal pressures.For aqueous fluids,the decrepitation temperature is correlated with the homogenisation temperature,but gas rich fluids give a distinct and characteristic low temperature decrepitation peak which can be used to recognize gas rich fluid inclusions.This information is useful in exploration for Au deposits,which are frequently associated with CO_2 rich and sometimes CH_4 rich fluids. This distinctive decrepitation occurs because the CO_2 rich inclusion fluids expand according to the gas law and develop internal pressures high enough to burst the host mineral grain at temperatures well below their homogenisation temperatures.In contrast,aqueous fluids condense to a liquid and vapour phase during post-entrapment cooling.Upon subsequent heating their internal pressures do not increase significantly until after homogenisation to a single phase occurs and hence they do not decrepitate"prematurely"as gas rich inclusions do. This behaviour is usually regarded as an annoyance in conventional microthermometric homogenisation studies,but can readily be used as an exploration aid to find mineralisation deposited from such gas rich fluids.Decrepitation results on samples from Cowra Ck, NSW,Australia,which have also been microthermometrically measured for CO_2 content,show that amounts of less than 5 mole % CO_2 are easily distinguished by decrepitation and amounts as low as 1 mole % CO_2 may be determinable. Examples of the use of acoustic decrepitation in the study of 6 gold mines in the Shandong and Hebei provinces of China are discussed.  相似文献   

4.
The Hujiayu Cu deposit,representative of the "HuBi-type" Cu deposits in the Zhongtiao Mountains district in the southern edge of the North China Craton,is primarily hosted in graphitebearing schists and carbonate rocks.The ore minerals comprise mainly chalcopyrite,with minor sphalerite,siegenite[(Co,Ni)_3S_4],and clausthalite[Pb(S,Se)].The gangue minerals are mainly quartz and dolomite,with minor albite.Four fluid inclusion types were recognized in the chalcopyrite-pyrite-dolomite-quartz veins,including CO_2-rich inclusions(type Ⅰ),low-salinity,liquid-dominated,biphase aqueous inclusions(type Ⅱ),solid-bearing aqueous inclusions(type Ⅲ),and solid-bearing aqueous-carbonic inclusions(type Ⅳ).Type I inclusion can be further divided into two sub-types,i.e.,monophase CO_2 inclusions(type Ⅰa) and biphase CO_2-rich inclusions(with a visible aqueous phase),and type Ⅲ inclusion is divided into a subtype with a halite daughter mineral(type Ⅲa) and a subtype with multiple solids(type Ⅲb).Various fluid inclusion assemblages(FIAs) were identified through petrographic observations,and were classified into four groups.The group-1 FIA,consisting of monophase CO_2 inclusions(type Ⅰa),homogenized into the liquid phase in a large range of temperatures from-1 to 28℃,suggesting post-entrapment modification.The group-2 FIA consists of type Ⅰb,Ⅲb and Ⅳ inclusions,and is interpreted to reflect fluid immiscibility.The group-3 FIA comprises type Ⅱ and Ⅲa inclusions,and the group-4FIA consists of type Ⅱ inclusions with consistent phase ratios.The group-1 and group-2 FIAs are interpreted to be entrapped during mineralization,whereas group-3 and group-4 FIAs probably represent the post-mineralization fluids.The solid CO_2 melting temperatures range from-60.6 to56.6℃ and from-66.0 to-63.4℃ for type Ⅰa and type Ⅳ inclusions,respectively.The homogenization temperatures for type Ⅱ inclusions range from 132 to 170℃ for group-3 FIAs and115 to 219℃ for group-4 FIAs.The halite melting temperatures range from 530 to 562℃ for typeⅢ b and Ⅳ inclusions,whereas those for type Ⅲa inclusions range from 198 to 398℃.Laser Raman and SEM-EDS results show that the gas species in fluid inclusions are mainly CO_2 with minor CH_4,and the solids are dominated by calcite and halite.The calcite in the hosting marble and dolomite in the hydrothermal veins have δ~(13)C_(V-pdb) values of-0.2 to 1.2‰ and-1.2 to-6.3‰,and δ~(18)O_(v-smow) values of 14.0 to 20.8 ‰ and 13.2 to 14.3‰,respectively.The fluid inclusion and carbon-oxygen isotope data suggest that the ore-forming fluids were probably derived from metamorphic fluids,which had reacted with organic matter in sedimentary rocks or graphite and undergone phase separation at 1.4-1.8 kbar and 230-240℃,after peak metamorphism.It is proposed that the Hujiayu Cu deposit consists of two mineralization stages.The early stage mineralization,characterized by disseminated and veinlet copper sulfides,probably took place in an environment similar to sediment-hosted stratiform copper mineralization.Ore minerals formed in this precursor mineralization stage were remobilized and enriched in the late metamorphic hydrothermal stage,leading to the formation of thick quartz-dolomite-sulfides veins.  相似文献   

5.
The Ordos Basin is well-known for the coexistence of oil, natural gas, coal and uranium. However, there has been little research to discuss the genetic relationship between them. In this paper, a case study of the Zaohuohao area in Dongsheng, Inner Mongolia, China, is conducted to investigate the genetic relationship between the natural gas and the uranium accumulation. Fluid inclusion data from the uranium-bearing sandstone samples indicate that the fluid inclusions formed in a gas-water transition zone. Using the homogeneous temperatures of aqueous inclusions coeval with hydrocarbon-bearing inclusions, combined with the buried history and paleo-temperature data, the gas-water transition zone reached the area at about 110 Ma. On the basis of this, the contents of Uranium (U) and Total Organic Carbon (TOC) of the samples were analyzed, and there was no obvious relation between them. With regard to the available data from both publications and this study, it is found that the U mineralization has a spatiotemporal accordance with the gas-water dispersal zone. Thus, it is believed that the natural gas in the gas-water zone is an effective reducer to the U-bearing ground water abundant in oxygen, which is the main factor to U accumulation. This result can be used as the reference to the U mines predicting and prospecting.  相似文献   

6.
Terrigenous clastic reservoir rocks are widespread in China,and nearly all the industrial oil and gas accumulations in eastern China occur in the clastic rocks.The study shows that organic inclusions are mostly distributed in the secondary fissures and pores which were ormed in the process of oil-rock interaction,rather than in the cements or secondary enlargements. The organic inclusions are dominantly organic gas-rich or are composed of pure hydrocarbons.Homogenization temperatures range mainly from 120℃ to 130℃,which shows a relatively high maturity of organic matter.Vertical and horizontal temperature changes provide the grounds for the investigation of basin evolution and thermal fluid-kinetics-model.Fluorescence spectral characteristics o the organic inclusions indicate that oils and gases in the area studied probably have experienced two-stage or two-time migration.Micro-fluorescence rescearch is one of the effective approaches to oil/source correlation and oil migration-stage determination.The abundance and occurrence of organic inclusions is one of the indicators of oil and gas abundance and accumulation in rock layers.With the help of other informatio,organic inclusions can provide the basis for the prospective assessment of oil and gas in clastic reservoir rocks.  相似文献   

7.
In order to recognize the impact of aqueous medium on gas yields and the kinetic behaviors of hydrogen isotope fractionation during organic matter thermal degradation, the gold tube apparatus was used to conduct thermal simulation experiments by mixing the nC18 with the water of different properties and proportions. The yields of natural gas components, the relation among hydrogen isotope composition of each component and the experimental temperatures vs. heating rates have been obtained, and the results indicate that under the higher temperature conditions, the hydrous experiment has obvious impact on gas yields, such as when more water is added, higher amounts of hydrocarbon gas and H2 are yielded, and the existence of water obviously prolongs the temperature interval with the existence of heavy hydrocarbon gas. It also shows that the hydrogen isotope of hydrocarbon gas generated by the hydrous experiment is obviously lighter than that generated by the anhydrous experiment, and with the increasing amount of added water, the δD value of hydrocarbon gas gradually decreases. Compared with gas yields, the variation of δD value is more sensitive to aqueous medium in the thermal simulation experiment. However, compared with the amount of the added water, the aqueous medium property has smaller impact on the gas yields, which still shows the inherit effect on hydrogen isotope composition of aqueous medium. Through the model simulation and the isotope fractionation behavior analysis, it is validated that the hydrogen isotope fractionation process can be well described by the chemical kinetic model. The difference of reaction fraction of normal methane and D-containing methane is large, corresponding to the same activation energy. The content of normal methane is obviously higher in the part with lower activation energy, while the content of D-containing methane is higher in the part with higher activation energy. Therefore, it will result in larger hydrogen isotope fractionation amplitude, and the δD values will be more sensitive to the variation of maturity. Meanwhile, the average activation energy of methane generation from nC18 in the hydrous experiment is higher than that in the anhydrous experiment, and the greater amount of added water, the larger the average activation energy of methane generation reaction. This has laid foundation for its exploratory application in the study of gas reservoir forming history and the gas-source correlation, which indicates the research and application prospects in this orientation.  相似文献   

8.
How to quantitatively evaluate the maturity of crude oils is still an open question. Mango discovered a remarkable compositional invariance of four isoheptane ratios in crude oils, and proposed a steady-state catalytic model for the origin of light hydrocarbons. According to this model, 2,4/2,3 dimethylpentane ratio is a pure temperature parameter. Bement, Mango et al. established the functional equation between the two parameters--light hydrocarbon temperature and burial temperature and applied it to the calculation of hydrocarbon-generating temperature, which provided a new choice for the study of oil maturity. In this paper, the Mango's parameters for hydrocarbons from the Tazhong area were calculated, the average K1 value is 1.06, which is in good consistency with the Mango's proposal that the K1 value is relatively stable. Calculated with the functional formula of hydrocarbon-generating temperature, the hydrocarbon-generating temperatures are with the range of 120-129℃, and the converted vitrinite reflectance (Ro) varies from 0.88% to 0.90%. This is well consistent with the maturity characteristics of neohopanes. The results have verified the reliability of this method.  相似文献   

9.
How to quantitatively evaluate the maturity of crude oils is still an open question. Mango discovered a remarkable compositional invariance of four isoheptane ratios in crude oils, and proposed a steady-state catalytic model for the origin of light hydrocarbons. According to this model, 2,4/2,3 dimethylpentane ratio is a pure temperature parameter. Bement, Mango et al. established the functional equation between the two parameters-light hydrocarbon temperature and burial temperature and applied it to the calculation of hydrocarbon-generating temperature, which provided a new choice for the study of oil maturity. In this paper, the Mango's parameters for hydrocarbons from the Tazhong area were calculated, the average K1 value is 1.06, which is in good consistency with the Mango's proposal that the K1 value is relatively stable. Calculated with the functional formula of hydrocarbon-generating temperature, the hydrocarbon-generating temperatures are with the range of 120-129℃, and the converted vitrinite reflectance (Ro) varies from 0.88% to 0.90%. This is well consistent with the maturity characteristics of neohopanes. The results have verified the reliability of this method.  相似文献   

10.
In this paper a thermogravimetry-differential thermal analysis method coupled with chromatography (TG-DTA-GC) has been adopted to simulate the generation of gaseous hydrocarbons from different hydrocarbon source rocks such as coals, mudstones, and carbonate rocks with different maturities. The temperature programming for thermal simulation experiment is 20℃/min from ambient temperature to 700℃. As viewed from the quantities and composition of generated gaseous hydrocarbons at different temperatures, it is shown that low-mature coal has experienced the strongest exothermic reaction and the highest loss of weight in which the first exothermic peak is relatively low. Low-mature coal samples have stronger capability of generating gaseous hydrocarbons than high-mature samples. The amounts and composition of gaseous hydrocarbons generated are closely related not only to the abundance of organic carbon in source rocks, but also to the type of kerogen in the source rocks, and their thermal maturity. In the present highly mature and over-mature rock samples organic carbon, probably, has already been exhausted, so the production of gaseous hydrocarbons in large amounts is impossible. The contents of heavy components in gaseous hydrocarbons from the source rocks containing type- Ⅰ and - Ⅱ kerogens are generally high ; those of light components such as methane and ethane in gaseous hydrocarbons from the source rocks with Ⅲ-type kerogens are high as well. In the course of thermal simulation of carbonate rock samples, large amounts of gaseous hydrocarbons were produced in a high temperature range.  相似文献   

11.
Measurements of the final dissociation temperature of gas-clathrate hydrates (TmCLA) are routinely used to determine the salinity of fluid inclusions which contain a volatile component in addition to water. Traditionally, experimental data are used to quantitatively relate TmCLA to the inclusion electrolyte concentration. Because of limitations in the experimental database, however, this method has hitherto not been applicable to the multivolatile fluid inclusions that are common in crustal rocks.A general solution to this problem is provided by statistical thermodynamics predictions of multivolatile clathrate stability. Published theoretical models explicitly account for the effect of aqueous NaCl in depressing the stability of clathrates composed of any mixture of CO2, N2, H2S, CH4 and higher-order hydrocarbons. Analysis of phase relations in complex clathrate systems shows that such theoretical predictions yield model salinities if the following fluid inclusion data are available: (1) the identity of the phase assemblage at TmCLA, (2) the relative concentrations of the volatile species, and (3) either the homogenization temperature of the volatile fluid fraction (bubble point or dew point, either stable or metastable), or an independent estimate of internal pressure at TmCLA. Additional data on fluid inclusion cation ratios can be incorporated in the calculations to recast equivalent weight percent aqueous NaCl in terms of effective electrolyte concentrations.New experimental data on mixed N2-CO2 clathrates, obtained from synthetic fluid inclusions, provide a test of both the model predictions and of the analytical procedure proposed for natural fluid inclusions. While the accuracy of the predictions varies between volatile compositions, the uncertainties in the salinities derived from the statistical thermodynamics method are generally of the order acceptable for geochemical applications. Applications to multivolatile, multi-electrolyte fluid inclusions from gold-quartz deposits illustrate the practical operations involved in determining salinity.  相似文献   

12.
油气和含油气包裹体及其在油气地质地球化学研究中的意义   总被引:36,自引:3,他引:36  
本文在综合前人研究的基础上,结合笔者的工作经验,提出了一个实用的油气和含油气包裹体分类方案,详细论述了各类油气和含油气包裹体的相态、组成和均一温度特征。在同一油气藏,均一温度越高,油相包裹体中的气态烃和挥发份的含量也越高。依据油相包裹体的均一温度的变化及其与同生水溶液包裹体的均一温度的关系可以研究油气藏在充填过程中油气组成,特别是气态烃和挥发份含量的演变。进而可以研究油气藏的油源--生油岩的类型和热演化程度。本文评述了依据油相包裹体和同生水溶液包裹体PVT相图推断其捕获温度和压力范围的有效性和局限性。最后讨论了各类油气和含油气包裹体的成因机制及其在油气地质和地球化学研究中的意义。  相似文献   

13.
为研究鄂尔多斯盆地中部地区马家沟组成藏期次和天然气运移方向与断裂活动的相关性,利用流体包裹体岩相学观察、激光拉曼光谱分析、均一温度和冰点温度的测定以及热力学PVT模拟方法对奥陶系马家沟组马五段储层的岩心样品进行了成分、温度和压力的测定与恢复.结果表明:构造裂缝脉体中充填的矿物为方解石、白云石和菱镁矿;脉体中共有4类流体包裹体,分别为富甲烷气体包裹体、含CO2富甲烷气体包裹体、含甲烷盐水包裹体和盐水包裹体,这4类流体包裹体均存在于方解石脉体中;构造裂缝脉体和溶孔中含甲烷流体包裹体的均一温度在130.1~179.6 ℃之间,与含甲烷流体包裹体同期的盐水包裹体的均一温度范围为112.3~173.3 ℃.结合生排烃史和埋藏史,证明早白垩世是马家沟组天然气的主要成藏期.沿断裂分布的各井的捕获压力和压力系数呈现由西南向东北递减的趋势,早白垩世的构造运动在北东向的断层中产生大量构造裂缝,为天然气的运移提供了通道,证明含甲烷的流体沿北东向断裂运移并充注成藏.   相似文献   

14.
15.
Interaction between oil and hydrothermal solutions of different compositions was experimentally studied in a wide range of temperature (260–490°C) and pressures (8–150 MPa). This study was based on a new technique involving simultaneous occurrence of water-hydrocarbon interaction and growth of quartz, calcite, and fluorite crystals with fluid inclusions from the same solution. Fluid inclusions were studied to characterize the behavior of oil and aqueous solutions at elevated and high temperatures and pressures. It was shown that, owing to interaction with hydrothermal solutions, oil is intensely removed from the source rock and accumulated in the frontal part of hydrothermal convective flow. During this process, the oil is partially transformed into hydrocarbons, light oil, semiliquid and solid bitumens. At temperatures of 300–350°C and pressures of 50–100 MPa, oil and its fractionation products migrate in hydrothermal solution mainly in a drop-liquid state. At higher temperatures (360–395°C), when the oil/water ratio in the initial mixture is no higher than 1/70–1/35, liquid and gaseous hydrocarbons are completely dissolved in hydrothermal solutions forming a complex homogenous water-hydrocarbon fluid. The fluid can exist and migrate in this state, but it becomes heterogeneous with decreasing P-T parameters. Under favourable structural and lithological conditions, this can lead to the formation of displaced oil-and-gas deposits, with oil enriched in light components. The experiments unambiguously confirmed the concept that bitumen inclusions in minerals can serve as indicators of hydrocarbon migration paths in the Earth’s crust.  相似文献   

16.
山西中条山铜矿峪铜矿流体演化特征   总被引:1,自引:0,他引:1  
王键  李碧乐  张晗  许庆林 《世界地质》2013,32(2):200-211
铜矿峪铜矿大地构造位置位于华北克拉通中部造山带南部,主容矿围岩为花岗闪长斑岩、二长花岗岩及变质基性火山岩。对不同阶段石英流体包裹体进行了包裹体岩相学、显微测温学和激光拉曼显微探针研究。结果表明,成矿流体包裹体可分为气液两相包裹体、含多子晶包裹体、含石盐子晶包裹体、含CO2 包裹体及纯CO2 包裹体。其中早阶段以富含多子晶包裹体( 均一温度为436. 2 ℃ ~ > 550 ℃,盐度( w ( NaCl) ) 为49. 34% ~ > 62%) 和含石盐子晶包裹体( 均一温度为345. 6 ℃ ~ > 550 ℃,盐度( w ( NaCl) ) 为29. 72% ~ > 62%) 为主。主成矿阶段主要由含石盐子晶包裹体( 均一温度为169. 1 ℃ ~ 324. 9 ℃,盐度( w ( NaCl) ) 为30. 47% ~ 39. 75%) 、气液两相包裹体( 均一温度介于159. 9 ℃ ~ 242. 9 ℃,盐度( w ( NaCl) ) 为1. 56% ~ 22. 31%) 组成并发现少量含CO2 包裹体 ( 均一温度为259. 7 ℃ ~ 320. 5 ℃,盐度( w ( NaCl) ) 为8. 93% ~ 13. 16%) 和纯CO2 包裹体( CO2 均一温度为24. 3 ℃ ~ 27. 22 ℃) 。晚成矿阶段仅发育气液两相包裹体( 均一温度为126. 9 ℃ ~ 212. 3 ℃,盐度( w ( NaCl) ) 为1. 56% ~ 7. 44 %) 。激光拉曼光谱分析包裹体气相成分主要为H2O、CO2、 HF 组成,晚期为CO2、N2。包裹体中普遍存在CO2。早阶段流体应为高温高盐高氧逸度NaCl - H2O - CO2 体系。主成矿阶段含气液两相包裹体与富CO2 相包裹体共存,表明流体发生了不混溶或沸腾现象。成矿晚阶段低温低盐度气液两相包裹体可能来源于大气降水。分析认为,铜矿峪铜矿成因类型属斑岩型。  相似文献   

17.
胜利油田火山岩辉石中岩浆包裹体成分及有关成因问题   总被引:5,自引:1,他引:4  
赫英  廖永胜 《地质论评》2000,46(6):638-644
对胜利油田火山岩中辉石及其中岩浆包裹体成分的研究表明:CO2气藏区和非CO2气藏区新生代火山岩辉石及其中岩浆包裹体成分有明显区别,前者中辉石为普通辉石,成分相对富SiO2,而贫Al2O3、TiO2、MgO和挥发成分;而后者中辉石为透辉石,成分相对贫SiO2和挥发份,而富Al2O3、TiO2和MgO。前者岩浆包裹体玻相中富含CO2,包裹体中的金属子矿物多为黄铁矿;而后者岩浆包裹体玻相中贫CO2;包裹  相似文献   

18.
热水溶液地球化学   总被引:8,自引:0,他引:8  
曾贻善 《地学前缘》1996,3(3):89-95
概述了热水溶液地球化学的主要研究内容和近年来在实验和理论研究方面的进展,包括高温高压下水的热力学性质、状态方程式、介电常数、电导率和电离平衡;NaCl-CO2-H2O体系及其边界体系(NaCl-H2O和CO2-H2O)的相关系、热力学性质和状态方程式,特别是利用人工流体包裹体技术和分子动力学模拟取得的新成果;高温高压电解质稀水溶液的电导测定;以HKF模型为基础,热水溶液中不同物种的标准偏摩尔热力学性质和高温高压有关物理化学参数的估算;热水溶液中的物种形成(热液流体中的矿物溶解度测定、电势测量和谱学研究);水和热水溶液结构的红外和拉曼谱学研究;水和热水溶液的传输性质(粘度和导热系数)。  相似文献   

19.
葛云锦  陈勇  周瑶琪 《岩矿测试》2008,27(3):207-210
论述了包裹体低温分析技术的原理以及进展。传统的流体包裹体低温分析技术是以显微冷冻测温测定无机盐体系为主,目前已发展到应用低温原位拉曼光谱技术对包裹体中的阳离子和阴离子进行定量-半定量分析。油气包裹体原位低温分析技术也取得了较大的突破,对不同成分油气包裹体低温下的相变过程取得了一定的认识,据此对油气包裹体进行分类,推测其主要成分,为油气包裹体计算提供基础参数。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号