Effects of uranium on hydrocarbon generation of hydrocarbon source rocks with type-Ⅲ kerogen

Organic-inorganic interaction exists universally and is important in the process of mineral resources formation.It is the essential reason why organic oil,gas,coal and inorganic uranium coexist,accumulate,and mineralize in the same sedimentary basins.Hydrocarbon-generating simulation experiment was conducted using low-mature hydrocarbon source rock containing kerogen type III with uranium(UO2CO3 solution)added to study the effects of uranium on the hydrocarbon generation of hydrocarbon source rocks.Experiment results show that uranium can enhance the yield of gas hydrocarbon,promote the total gas output,and increase the total hydrocarbon production(mass or volume).Uranium may lower the hydrocarbon generation threshold temperature and lead to the generation of liquid hydrocarbon in the relative low temperature of hydrocarbon source rock.Uranium can enhance the yield of saturated hydrocarbon,promote the low molecular weight hydrocarbons generating,and in turn increase the content of CH4 and the content of dry gas of the generated hydrocarbons.Uranium is one of the potential inorganic accelerating factors of the immature hydrocarbons.     

Effects of uranium on hydrocarbon generation of hydrocarbon source rocks with type-III kerogen

Organic-inorganic interaction exists universally and is important in the process of mineral resources formation.It is the essential reason why organic oil,gas,coal and inorganic uranium coexist,accumulate,and mineralize in the same sedimentary basins.Hydrocarbon-generating simulation experiment was conducted using low-mature hydrocarbon source rock containing kerogen type III with uranium(UO2CO3 solution)added to study the effects of uranium on the hydrocarbon generation of hydrocarbon source rocks.Experiment results show that uranium can enhance the yield of gas hydrocarbon,promote the total gas output,and increase the total hydrocarbon production(mass or volume).Uranium may lower the hydrocarbon generation threshold temperature and lead to the generation of liquid hydrocarbon in the relative low temperature of hydrocarbon source rock.Uranium can enhance the yield of saturated hydrocarbon,promote the low molecular weight hydrocarbons generating,and in turn increase the content of CH4 and the content of dry gas of the generated hydrocarbons.Uranium is one of the potential inorganic accelerating factors of the immature hydrocarbons.     

Natural gas origins of large and medium-scale gas fields in China sedimentary basins

China sedimentary basins present abundant natural gas resource thanks to its unique geological settings.Marine highly-matured hydrocarbon source rocks,widespread coal-measure strata and low temperature Quaternary saline strata,etc.,indicate the wide foreground of China natural gas resources. Up to now,most of the petroliferous basins have been discovered to have wholesale natural gas accumulation from Precambrian,Paleozoic,Mesozoic to Cenozoic in the east,the central,the west and the coast of China.These large and medium-scale gas reservoirs are mainly composed of hydrocarbon gas with big dry coefficient,tiny non-hydrocarbon,wide carbon isotope distribution and varying origin types,the hydrocarbon gas includes coal-formed gas,oil-formed gas,biogenic gas and inorganic gas, etc.Coal-formed gas is the main type of China natural gas resources,in particular several explored large-scale gas fields(>100 billion cubic meter)of Kela 2,Sulige and Daniudi,etc.,they all belong to coal-formed gas fields or the gas fields consisting mostly of coal-formed gas.Oil-formed gas is also abundant in China marine basins,for example marine natural gas of Sichuan Basin generated from crude oil cracking gas.Primary and secondary biogenic gas fields were discovered respectively in the Qaidam Basin and Western Slope of Songliao Basin.In addition,inorganic gases are mainly distributed in the eastern China,in particular the Songliao Basin with abundant carbon dioxide accumulation,indicating that the eastern China present large exploration potential of inorganic gas.     

石油双机(有机+无机)混合成因的研究与探索

石油与天然气的成因问题关系到我国乃至世界各国能源结构的配置及其能源在社会与经济发展中的地位和导向.自从17世纪展开对石油的有机与无机成因的争论以来,至今已有约300~400年的历史.尽管有机成因论占据了统治地位,但是无机成因论亦不断地在兴起!通过对这二者的理解和研究,从理论上讲他们都具有一定的物质基础和论据.基于对国内、外一些特异油田的生储环境,原油中所富含的微量金属元素的聚集与散失,某些油田中并未找到卟啉分子这样的生物标志物,碳、氢、氧化学合成实验等方面取得了一定的成效,故全盘否定无机生油的论点和论据确尚感为时过早或欠妥!显然,在以有机物成油为主体的前提下,无机物亦可生成部分石油,并通过运移、渗透到各油田的储集层中应是完全可能的.基于这样的分析、研究和探索,现提出石油的双机(a有机+b无机)混合成因的新理念.诚希能在今后的石油工业发展中,从理论、技术、实验和实践中强化对双机混合成因新理念的深化研究与探索,以达深切理解和扩展石油生、储空间环境等是不无裨益的!     

第二深度空间(5000~10000 m)油、气形成与聚集的深层物理与动力学响应

在当今全球各国对油、气能源的需求和我国在工业化进程中油气能源十分紧缺的前提下,共享世界油、气能源的同时,必须立足于本土,迅速建立起安全、稳定,且可保证持续供给的油、气能源战略后备基地.油、气田勘探和开采中,尚存在着大于或远大于通常所规范的油、气生成稳定温度和深度限定,而向深部勘察油、气的理念又受到传统油、气成因理论的严峻挑战.为此,近些年来,通过对沉积建造、结晶基底,深部油气生成的物理（主指温度、压力）条件、物源和聚集储存空间的研究,提出：①沉积盆地中存在双相（陆相+海相）沉积建造,而基底则分为中、新生代沉积基底和古老的变质岩结晶基底,即双层基底;②地壳深部介质的物理－化学属性和变质岩及存储空间为油、气的生成和聚集提供了物质基础;③厘定了在有机成因主导下,油、气混合成因（有机+无机）的新理念;④第二深度空间（5000~10000 m）的油、气探查和开发将必是未来深部发现大型和超大型油、气田和深化研究的必然轨迹.     

Mineral photoelectrons and their implications for the origin and early evolution of life on Earth

Energy is the key issue of all life activities.The energy source and energy yielding pathway are the key scientific issues of the origin and early evolution of life on Earth.Current researches indicate that the utilization of solar energy in large scale by life was an important breaking point of the early evolution of life on Earth and afterwards life gradually developed and flourished.However,in the widespread biochemical electron transfer of life activities,it is still not clear whether the electron source is sun or how electrons originated from sun.For billions of years,the ubiquitous semiconducting minerals in epigeosphere absorb solar energy,forming photoelectrons and photoholes.In reductive and weak acidic environment of early Earth,when photoholes were easily scavenged by reducing matters,photoelectrons were separated.Photoelectrons could effectively reduce carbon dioxide to organic matters,possibly providing organic matter foundation for the origin of life.Photoelectrons participated in photoelectron transfer chains driven by potential difference and transfer into primitive cells to maintain metabolisms.Semiconducting minerals,by absorbing ultraviolet,also protected primitive cells from being damaged by ultraviolet in the origin of life.Due to the continuous photoelectrons generation in semiconducting minerals and utilization by primitive cells,photoelectrons from semiconducting minerals’photocatalysis played multiple roles in the origin of life on early Earth,such as organic synthesis,cell protection,and energy supply.This mechanism still plays important roles in modern Earth surface systems.     

Natural gas generation model and its response in accumulated fluids in the Yinggehai basin

The generation of natural gases is much more complicated in comparison with liquid petro-leum in that natural gases could be generated from both humic and sapropelic organic matter at different stages and that natural gases could be organic and inorganic …     

The palaeomagnetism of muddy sediment cores from the Inner Sound,Northwest Scotland,and the glacial and post-glacial history of sedimentation in the area

Josephinite is a terrestrial iron-nickel alloy with an intergrown magnesium silicate, and arsenide and sulphide phases, and andradite garnet; several specimens have been found to contain elemental silicon and CaO · 2“FeO”. Josephinite is not awaruite, an iron-nickel mineral formed by serpentinization of ultramafic rocks. Because of its geologic setting and unique mineralogy we propose that josephinite might have originated in the region of the coremantle boundary, was transported via a deep-mantle “plume” and diatreme mechanism into lithosphere mantle that has been emplaced in the Klamaths by ophiolite obduction. Regardless of such a hypothesis, we report here the discovery of terrestrial silicon occurring with josephinite, which seems to preclude a lithosphere environment of origin for josephinite.     

Organic compounds in thermal water: The Mutnovskii area and the Uzon caldera

New data are reported relating to the presence and relative concentrations of organic compounds of medium volatility in samples from the water of hot springs and in the condensate of a steam–water mixture from wells drilled in the Mutnovskii geothermal area and from a well and springs in the Uzon caldera. The Mutnovskii area was found to contain 95 compounds belonging to 16 homologous series, with 71 compounds (12 series) in the Uzon caldera. Among these we found homologous series of biologically important compounds: carbonic acids, alcohols, ethers, aldehydes, ketones, and others. Evidence was obtained for a contribution of the abiogenic component in organic matter from sterile condensates of an overheated steam–water mixture from wells (alkanes, aromatic hydrocarbons, ketones, alcohols, and others) and in thermal water from natural discharges (in particular, alkanes and chlorine-containing hydrocarbons). The results of this study can be used for the preparation and conduction of laboratory experiments in prebiological chemistry under conditions that simulate a hydrothermal environment.     

Hydrocarbons in the water, particulate matter, seston, and bottom sediments of the White Sea in the late summer

Aliphatic and polycyclic aromatic hydrocarbons were studied in water, filtration and separation particulate matter, seston, and bottom sediments with the aim to determine their concentrations and origin and compare them with the concentrations of lipids and C_org (August 2006). The effect of anthropogenic hydrocarbons was identified mostly in the Northern Dvina mouth area and in the apex of Dvina Bay. In other parts of the sea, natural compounds dominate in all examined objects, since anthropogenic hydrocarbon cannot pass through the Northern Dvina-the White Sea geochemical barrier. The low temperatures in the high-latitude water areas are shown not to reduce the rate of diagenetic processes in the sedimentary strata.     

Petroleum Hydrocarbon Bioventing Kinetics Determined in Soil Core, Microcosm, and Tubing Cluster Studies

Aerobic biodegradation of vapor-phase petroleum hydrocarbons was evaluated in an intact soil core from the site of an aviation gasoline release. An unsaturated zone soil core was subjected to a flow of nitrogen gas, oxygen, water vapor, and vapor-phase hydrocarbons in a configuration analogous to a biofilter or an in situ bioventing or sparging situation. The vertical profiles of vapor-phase hydrocarbon concentration in the soil core were determined by gas chromatography of vapor samples. Biodegradation reduced low influent hydrocarbon concentrations by 45 to 92 percent over a 0.6-m interval of an intact soil core. The estimated total hydrocarbon concentration was reduced by 75 percent from 26 to 7 parts per million. Steady-state concentrations were input to a simple analytical model balancing advection and first-order biodegradation of hydrocarbons. First-order rate constants for the major hydrocarbon compounds were used to calibrate the model to the concentration profiles. Rate constants for the seven individual hydrocarbon compounds varied by a factor of 4. Compounds with lower molecular weights, fewer methyl groups, and no quaternary carbons tended to have higher rate constants. The first-order rate constants were consistent with kinetic parameters determined from both microcosm and tubing cluster studies at the field site.     

地壳的新的地球物理模型与石油的无机成因说

根据深地震测深法，大爆破，天然地震转换波法，区域对比折射比，共深度点法，结合重，磁，电法等地球物理方法，建立了含油气盆地的“缺花岗岩”型的地壳模型，这种模型地地质条件下费托合成无机油气；近期提出的深部－浅部“立交桥模型”更为这种油气生成，运移成藏提供了可能；而沥青，干酪根的Ｐｂ，Ｓｒ，Ｎｄ同位素数据则为原油的无机成因揭示了十分可靠的证据，原油中Ｓｉ－Ｃ键有机化全物的发现更为这种形成机理提供了一个重     

Classification and origin of natural gases from Lishui Sag,the East China Sea Basin

Natural gases discovered up to now in Lishui Sag, the East China Sea Basin, differ greatly in gaseous compositions, of which hydrocarbon gases amount to 2%–94% while non-hydrocarbon gases are dominated by CO₂. Their hydrocarbon gases, without exception, contain less than 90% of methane and over 10% of C₂ ⁺ heavier hydrocarbons, indicating a wet gas. Carbon isotopic analyses on these hydrocarbon gases showed that δ ¹³C₁, δ ¹³C₂ and δ ¹³C₃ are basically lighter than ?44‰, ?29‰ and ?26‰, respectively. The difference in carbon isotopic values between methane and ethane is great, suggesting a biogenic oil-type gas produced by the mixed organic matter at peak generation. δ ¹³ \(C_{CO_2 } \) values of nonhydrocarbon gases are all heavier than ?10‰, indicating a typical abiogenic gas. The simulation experiment on hydrocarbon generation of organic matter in a closed gold-tube system showed that the proportion of methane in natural gases produced by terrigenous organic matter in the Lingfeng Formation marine deposit is obviously higher than that in natural gases derived from the aquatic and terrigenous mixed organic matter in the Yueguifeng Formation lacustrine deposit, consequently the proportion of heavier hydrocarbons of the former is remarkably lower than that of the latter. Moreover, δ ¹³C₁ values of natural gases produced by terrigenous organic matter in the Lingfeng Formation marine deposit are about 5‰ heavier than those of natural gases derived from the aquatic and terrigenous mixed organic matter in the Yueguifeng Formation lacustrine deposit while δ ¹³C₂ and δ ¹³C₃ values of the former are over 9‰ heavier than those of the latter. Currently the LS36-1 oil-gas pool is the only commercial oil-gas reservoir in Lishui Sag, where carbon isotopic compositions of various hydrocarbon components differ greatly from those of natural gases produced by the Lingfeng Formation organic matter but are very similar to those of natural gases derived from the Yueguifeng Formation organic matter, therefore, natural gases in the LS36-1 oil-gas pool are mainly derived from the Yueguifeng Formation lacustrine source rock rather than the Lingfeng Formation marine or Mingyuefeng Formation coal-measures source rocks.     

Classification and origin of natural gases from Lishui Sag,the East China Sea Basin

Natural gases discovered up to now in Lishui Sag, the East China Sea Basin, differ greatly in gaseous compositions, of which hydrocarbon gases amount to 2%–94% while non-hydrocarbon gases are dominated by CO₂. Their hydrocarbon gases, without exception, contain less than 90% of methane and over 10% of C₂ ⁺ heavier hydrocarbons, indicating a wet gas. Carbon isotopic analyses on these hydrocarbon gases showed that δ ¹³C₁, δ ¹³C₂ and δ ¹³C₃ are basically lighter than −44‰, −29‰ and −26‰, respectively. The difference in carbon isotopic values between methane and ethane is great, suggesting a biogenic oil-type gas produced by the mixed organic matter at peak generation. δ ¹³ \( C_{CO_2 } \) values of nonhydrocarbon gases are all heavier than −10‰, indicating a typical abiogenic gas. The simulation experiment on hydrocarbon generation of organic matter in a closed gold-tube system showed that the proportion of methane in natural gases produced by terrigenous organic matter in the Lingfeng Formation marine deposit is obviously higher than that in natural gases derived from the aquatic and terrigenous mixed organic matter in the Yueguifeng Formation lacustrine deposit, consequently the proportion of heavier hydrocarbons of the former is remarkably lower than that of the latter. Moreover, δ ¹³C₁ values of natural gases produced by terrigenous organic matter in the Lingfeng Formation marine deposit are about 5‰ heavier than those of natural gases derived from the aquatic and terrigenous mixed organic matter in the Yueguifeng Formation lacustrine deposit while δ ¹³C₂ and δ ¹³C₃ values of the former are over 9‰ heavier than those of the latter. Currently the LS36-1 oil-gas pool is the only commercial oil-gas reservoir in Lishui Sag, where carbon isotopic compositions of various hydrocarbon components differ greatly from those of natural gases produced by the Lingfeng Formation organic matter but are very similar to those of natural gases derived from the Yueguifeng Formation organic matter, therefore, natural gases in the LS36-1 oil-gas pool are mainly derived from the Yueguifeng Formation lacustrine source rock rather than the Lingfeng Formation marine or Mingyuefeng Formation coal-measures source rocks.

     

沉积盆地、结晶基底和油、气成因理念与第二深度空间勘探和开发

在石油、天然气的勘探和开发研究中,涉及到深部空间的介质、结构和属性,在沉积建造上涉及到陆相沉积、海相沉积和火山岩相,在油、气成因理论上涉及到有机成因和无机成因,在机制上涉及到深部流体的分异、调整、运移和动力作用.这些本质性问题的研究和探讨是人们十分关注的科学领域.基于油、气生、储和形成的理论、应用和成效的研究提出,有几个基础性的理念问题必须重新认识,特别是沉积建造与古老变质岩结晶基底;双相（海相和陆相）沉积建造与盆地的内涵和双基（有机和无机）混合油、气成因理念.清晰地厘定这些认识不仅有益于对油、气形成、聚集和勘探及开发给出一个更为科学的深部空间,即第二深度空间（5000~10000 m）的油、气勘探,而更为重要的是基于对这些理念的重新认识和深化研究可构建新的思路或理论,且在新的理念导向下,强化油、气深部勘探,以期能在理论研究和实践应用中取得新的成效,发现大型与超大型油、气田.     

Hydrocarbons in the atmosphere

Trace concentrations of highly reactive hydrocarbons of biogenic origin have been proposed for some time as being important in aerosol formation processes in the atmosphere. More recently, assessments of potential photochemical reactions in the troposphere have proposed a role in the atmospheric ozone cycle for hydrocarbons, even for compounds such as methane that had previously been considered nonreactive. An assessment of the atmospheric hydrocarbon reaction system has been limited by a lack of observational information on the nature of conditions in the remote or non-urban atmosphere. Recent data on terpene concentrations and other biogenic hydrocarbon compounds are presented. Data on ethane and acetylene from aircraft samples taken over the north and south Pacific Ocean show concentrations in the 0.5 to 1 /m³ range for ethane and in the 0.05 to 0.3 g/m³ range for acetylene. A concentration gradient is present for these compounds between the northern and southern hemisphere. A rudimentary global concentration pattern for these C₂ compounds has been developed on the basis of recent data.     

Hydrocarbon gases (C1–C5) and organic matter in bottom sediments of the Ivankovo Reservoir on the Volga River

The results of studying the composition of hydrocarbon gases (C₁–C₅) and organic matter in bottom sediments of the Ivankovo Reservoir in 1995, 2004, and 2005 are given. The methods used in the study include vapor-phase gas chromatography, instrumental pyrolysis gas chromatography, and mass-spectrometry for determining organic carbon δ ¹³C_org. The gas field of bottom sediments in different regions of the reservoir varies widely in terms of gas saturation and the spectrum of hydrocarbon gases. This suggests the heterogeneous composition of organic matter in the sediments and different conditions of its input and transformation processes. The gases were found to contain saturated hydrocarbons from methane to pentane C₁–C₅, including isomers i-C₄ and i-C₅ and unsaturated compounds C₂–C₄. A correlation was found to exist between methane distribution and the distribution of its more high-molecular homologues, which confirms their genetic relationship in bottom sediments. The obtained results show an increase in the rate of microbiological processes and organic matter transformation for most regions in the Ivankovo Reservoir. The only exceptions are the zones of Moshkovichskii Bay and the sections at Gorodnya and Konakovo, where technogenic organic matter is being accumulated. The high information value of hydrocarbon gases as biogeochemical markers of the sources of organic matter and the rates of its transformation is demonstrated. The isotopic composition of organic-matter carbon in the bottom sediments of the Ivankovo Reservoir δ ¹³C varies from ?26.21 to ?30.86‰.     

Weathering of Oil in a Surficial Aquifer

The composition of crude oil in a surficial aquifer was determined in two locations at the Bemidji, MN, spill site. The abundances of 71 individual hydrocarbons varied within 16 locations sampled. Little depletion of these hydrocarbons (relative to the pipeline oil) occurred in the first 10 years after the spill, whereas losses of 25% to 85% of the total measured hydrocarbons occurred after 30 years. The C_6‐30 n‐alkanes, toluene, and o‐xylene were the most depleted hydrocarbons. Some hydrocarbons, such as the n‐C_10–24 cyclohexanes, tri‐ and tetra‐ methylbenzenes, acyclic isoprenoids, and naphthalenes were the least depleted. Benzene was detected at every sampling location 30 years after the spill. Degradation of the oil led to increases in the percent organic carbon and in the δ ¹³C of the oil. Another method of determining hydrocarbon loss was by normalizing the total measured hydrocarbon concentrations to that of the most conservative analytes. This method indicated that the total measured hydrocarbons were depleted by 47% to 77% and loss of the oil mass over 30 years was 18% to 31%. Differences in hydrocarbon depletion were related to the depth of the oil in the aquifer, local topography, amount of recharge reaching the oil, availability of electron acceptors, and the presence of less permeable soils above the oil. The results from this study indicate that once crude oil has been in the subsurface for a number of years there is no longer a “starting oil concentration” that can be used to understand processes that affect its fate and the transport of hydrocarbons in groundwater.     

也谈地壳内第二深度空间石油、天然气的形成及勘探前景

在当前国内油气供需紧张的严峻形势下,开展"第二深度空间"的油气勘探"势在必行",也是"当务之急"."第二深度空间"的油气勘探需解决3个问题.一是油气无机成因的地球化学证据.原油、沥青、干酪根的Pb,Sr,Nd同位素示踪、原油中异常高含量的金属微量元素、原油中有机硅化合物的发现等均表明原油可以由无机反应而生成.二是油气无机成因论是可以指导油气勘探的.油气的分布与中地壳的低速、高导层的耦合表明有成因关系,中地壳的低速、高导层是油气的发生器,也是初始储层,据此可以对油气田进行预测.柴达木盆地昆北花岗岩油田的发现是一典型案例.三是"第二深度空间"的油气勘探需要地球物理方法和技术的支撑.目前第4代采集处理新理论、新方法业已提出.地球物理学家已经把深部勘探的新方法、新技术提到议事日程.总之,"第二深度空间"的油气勘探是有理论依据的,是可能的,是可操作的.发现大型、超大型油气田指日可待.