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1.
《中国科学D辑(英文版)》2008,(Z1)
Based on the examination of the global researches on oil and gas provinces and large gas fields and the analysis of the features,attributes and distribution of large gas provinces and gas fields,this paper puts forward three indicators of determining large oil and gas provinces:spatial indicator,reservoir-forming indicator and resource indicator.It classifies the gas accumulated areas and large gas provinces in China and analyzes the controlling factors on the distribution of large gas provinces and large gas fields:the lateral distribution is mainly controlled by high-energy sedimentary facies and constructive diagenetic facies,palaeo-highs and their periclinal zones,deep faults,etc,and the vertical distribution is mainly controlled by unconformities,series of evaporates and deep low-velocity highly-conductive beds,etc.It also reveals the main geological characteristics of large gas provinces and large gas fields in China.Large gas fields in four-type basins have their own characteristics and onland large gas fields are dominantly developed in foreland basins and craton basins;there are three types of gas sources,of which,coal is the main source with high gas generating intensity and varying origins;reservoir rocks of the large gas fields(provinces)are of various types and dominated generally by low-middle permeability and porosity pore-type reservoirs;structural traps and litho-stratigraphic traps coexist in Chinese large gas fields and form dense high abundance and large-area low and middle-abundance large gas fields;most of the large gas fields have late hydrocarbon-generation peaks and reservoir formation,and experienced the process of multiple-stage charging and late finalization; large gas provinces(fields)have good sealing and preservation conditions,and evaporates seals are largely developed in large and extra-large gas fields.This paper intends to shed light on the exploration and development of large gas fields(provinces)through analyzing their geological characteristics. 相似文献
2.
《中国科学D辑(英文版)》2008,(Z1)
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. 相似文献
3.
Carbon and hydrogen isotopic characteristics of natural gases from the Luliang and Baoshan basins in Yunnan Province, China 总被引:5,自引:1,他引:5
XU Yongchang LIU Wenhui SHEN Ping WANG Wanchun WANG Xiaofeng Tenger YAN Yaomin & LIU Ruobin . Lanzhou Center of Oil & Gas Resources Institute of Geology Geophsics Chinese Academy of Sciences Lanzhou China . Research Institute of Petroleum Exploration Production SINOPEC Beijing China . South Branch of Petroleum Exploration Production Company SINOPEC Kuming China 《中国科学D辑(英文版)》2006,49(9):938-946
The Luliang and Baoshan basins are two small ba- sins in Yunnan Province. In the recent ten years or so, there have been found a number of natural gas pools of commercial importance in the two basins. Although the gas pools are small in size, the natural … 相似文献
4.
Low-mature gases and typical low-mature gas fields in China 总被引:2,自引:0,他引:2
No natural gas pool of industrial importance could be formed at the low-evolution stage of organic matter. In the 1980s, on the basis of the development in exploration practice, the hypotheses of bio-thermo-catalytic transitional zone gases and early thermogenic gases were proposed. The lower-limit Ro values for the formation and accumulation of natural gases of industrial importance have been expanded to 0.3%―0.4%. In the light of the two-stage model established on the basis of carbon isotope fractionation in coal-type natural gases, the upper-limit Ro values have been set at 0.8%―1.0%. In terms of the geological practice in the low-mature gas zones and China's main coal-type gas fields, it is feasible and proper to set the upper-limit Ro value of low-mature gases at 0.8%. Supper-large gas fields such as the Urengoy gas field in western Siberian Basin should belong to low-mature gas fields, of which the natural gas reserves account for more than 20% of the global proven reserves, providing strong evidence for the significance of such a type of resources. The proven natural gas reserves in the Turpan-Hami Basin of China have almost reached 1000 × 108 m3. The main source rocks in this area are the Jurassic Xishanyao Formation, which occurs as a suite of coal series strata. The corresponding thermal evolution indices (Ro ) are mainly within the range of about 0.4%―0.8%, the δ 13C1 values of methane vary between-44‰ and-39‰ (correspondingly Ro =0.6%―0.8%), and those of ethane are within the range of-29‰―-26‰, indicating that natural gases in the Turpan-Hami Basin should be designated to coal-type low-mature gases. The light hydrocarbon evolution indices of natural gases also fall within the area of low evolution while the precursor type of light hydrocarbons also shows the characteristics of the coal-type. The geological background, carbon isotopic composition and light hydrocarbon index all provide strong evidence suggesting that the proven natural gases in the Turpan-Hami Basin are low-mature gases. In China a gas field with the gas reserves reaching 300 ×108 m3 can be defined as a large gas field, and thus the proven low-mature gases in the Turpan-Hami Basin are equivalent to the reserves of three large gas fields. Its existence is of great significance in research on and exploration of low-mature gases in China. 相似文献
5.
《中国科学D辑(英文版)》2008,(Z1)
The components and carbon isotope of gases in inclusions are one of the most important geochemical indexes for gas pools.The analysis results of the components and carbon isotope of gases from inclusions in reservoir layers of Upper Palaeozoic gas pools in the Ordos Basin show that most inclusions grown in reservoir sandstone are primary inclusions.There is only a little difference about the components and carbon isotope between the well gases and the secondary inclusions gases.This indicated that the epigenetic change of gas pools is little.This difference between the well gases and the secondary inclusions gases is caused by two reasons:(i)The well gases come from several disconnected sand bodies buried in a segment of depth,while the inclusion gases come from a point of depth.(ii)The secondary inclusions trapped the gases generated in the former stage of source rock gas generation,and the well gases are the mixed gases generated in all the stages.It is irresponsible to reconstruct the palaeo-temperature and palaeo-pressure under which the gas pool formed using carbon dioxide inclusions. 相似文献
6.
Medium-giant gas fields refer to those whose proved reserves are or more than 10 × 109 m3. Now, 30 such fields have been found in China. The main controlling factors of their formation are as follows:gas-generating
center and its surroundings; traps related to paleo-uplift in the gas-generating area; traps of medium-giant size hidden in
low-medium rank coal-bearing series and those above or beneath the coal measures; late reservoir formation; poretype reservoir
in gas-generating area and well-developed regional cap rock. 相似文献
7.
Oxygen and carbon isotope composition from the UHP Shuanghe marbles, Dabie Mountains, China 总被引:5,自引:0,他引:5
Investigations on the oxygen and carbon isotope compositions from the ultrahigh-pressure (UHP)-metamorphosed Shuanghe marbles,
that occur as a member of a UHP slab, show that the δ18 O values range from +11.1% to+20.5% SMOW, and δ13 C from+1.0% to+5.7% PDB, respectively. The variations in isotope compositions show a centimeter scale of homogeneity and
a heterogeneity of regional scale larger than 1 meter.
In contrast to the eclogite marbles from Norway, the Shuanghe marbles have inherited the carbon isotope compositions from
their sedimentary precursor. The δ13C shows positive correlation to the content of dolomite. The depletion in18O, compared with the pmtolithic carbonate strata, might result from three possible geological processes: 1) exchanging oxygen
isotope with meteoric water before the UHP metamorphism, 2) decarbonation during the UHP metamorphism, and 3) exchanging oxygen
isotope with country gneiss at local scale during retrograde metamorphism.
It seems that the advection of fluid in the orogenic belt was very limited during subduction and exhumation of UHP rocks.
Project supported by a U. S. -China cooperative project led by Prof. Cong Bolin of the Institute of Geology. Chinese Acade-my
of Sciences, and Prof. J. G. Liou of the Department of Geological and Environmental Sciences, Stanford University and by the
National Natural Science Foundation of china (Grant No. 49794042). Chinese Academy of Sciences (Grant No. KZ951-A1-401r, and
National Science Foundation (Grant No. EAR-95-26700). 相似文献
8.
《中国科学D辑(英文版)》2008,(Z1)
The Ordos Basin,the second largest sedimentary basin in China,contains the broad distribution of natural gas types.So far,several giant gas fields have been discovered in the Upper and Lower Paleozoic in this basin,each having over 1000×10 8 m 3 of proven gas reserves,and several gas pools have also been discovered in the Mesozoic.This paper collected the data of natural gases and elucidated the geochemical characteristics of gases from different reservoirs,and then discussed their origin.For hydrocarbons preserved in the Upper Paleozoic,the elevatedδ13C values of methane,ethane and propane indicate that the gases would be mainly coal-formed gases;the singular reversal in the stable carbon isotopes of gaseous alkanes suggests the mixed gases from humic sources with different maturity.In the Lower Paleozoic,theδ13C 1 values are mostly similar with those in the Upper Paleozoic,but theδ13C 2 andδ13C 3 values are slightly lighter,suggesting that the gases would be mixing of coal-type gases as a main member and oil-type gases.There are multiple reversals in carbon isotopes for gaseous alkanes,especially abnormal reversal for methane and ethane(i.e.δ13C 1 >δ13C 2 ),inferring that gases would be mixed between high-mature coal-formed gases and oil-type gases.In the Mesozoic,the δ13Cvalues for gaseous alkanes are enriched in 12C,indicating that the gases are mainly derived from sapropelic sources;the carbon isotopic reversal for propane and butane in the Mesozoic is caused by microbial oxidation and mixing of gases from sapropelic sources with different maturity.In contrast to the Upper Paleozoic gases,the Mesozoic gases are characterized by heavier carbon isotopes of iso-butane than normal butane,which may be caused by gases generated from different kerogen types. Finally,according toδ13C 1 -Ro relationship and extremely low total organic carbon contents,the Low Paleozoic gases would not be generated from the Ordovician source as a main gas source,bycontrast, the Upper Paleozoic source as a main gas source is contributed to the Lower Paleozoic gases. 相似文献
9.
Organic carbon and nitrogen stable isotopes in the intertidal sediments from the Yangtze Estuary, China 总被引:2,自引:0,他引:2
The natural isotopic compositions and C/N elemental ratios of sedimentary organic matter were determined in the intertidal flat of the Yangtze Estuary. The results showed that the ratios of carbon and nitrogen stable isotopes were respectively −29.8‰ to − 26.0‰ and 1.6‰–5.5‰ in the flood season (July), while they were −27.3‰ to − 25.6‰ and 1.7‰–7.8‰ in the dry season (February), respectively. The δ13C signatures were remarkably higher in July than in February, and gradually increased from the freshwater areas to the brackish areas. In contrast, there were relatively complex seasonal and spatial changes in stable nitrogen isotopes. It was also reflected that δ15N and C/N compositions had been obviously modified by organic matter diagenesis and biological processing, and could not be used to trace the sources of organic matter at the study area. In addition, it was considered that the mixing inputs of terrigenous and marine materials generally dominated sedimentary organic matter in the intertidal flat. The contribution of terrigenous inputs to sedimentary organic matter was roughly estimated according to the mixing balance model of stable carbon isotopes. 相似文献
10.
ZHAO Quanhong WANG PinXian CHENG Xinrong Wang Jiliang Huang Baoqi XU Jian ZHOU Zhen JIAN Zhimin 《中国科学D辑(英文版)》2001,44(10):943-951
High-resolution δ13C records are presented for the Miocene benthic foraminifersCibicidoides wuellerstorfi andC. kullenbergi (24-5 Ma) and the planktonic foraminiferGlobigerinoides sacculifer (18-5 Ma) from ODP Site 1148A (18° 50.17’N, 116° 33.93’E, water depth 3308.3 m), northern South China Sea. The general pattern of parallel benthic and planktonic δ13C shows a decrease trend of δ13C values from the early-middle Miocene to the middle-late Miocene. Two distinct δ13C positive excursions at 23.1-22.2 and 17.3-13.6 Ma, and two negative excursions at 10.2-9.4 and 6.9-6.2 Ma have been recognized. All these events are cosmopolitan, providing the good data for the stratigraphic correlation of the South China Sea with the global oceans as well as for studying the changes of the global carbon reservoir and its corresponding climate. 相似文献
11.
根据鄂尔多斯盆地苏里格气田以往实测和新测的共17口井51块岩样超声波实验数据,得到304组不同孔隙度和不同含水饱和度下对应的纵横波速度、泊松比等弹性参数.重新优选计算体积模量和泊松比与含气饱和度的关系,表明苏里格气田上古生界二叠系石盒子组盒8致密砂岩储层的模型与Brie模型(e=2)相似度最高.由此建立的苏里格气田储层岩石物理模型,更好的表征了致密岩石储层物理参数随含气饱和度变化规律,为该区储层预测提供了理论依据.致密储层岩石物理模型研究成果应用于苏里格气田多波地震资料气水预测中,实际例子表明该模型适用于该区的储层和含气性预测,并取得了较好的效果. 相似文献
12.
Changqun Cao Wei Wang Lujun Liu Shuzhong Shen Roger E. Summons 《Earth and Planetary Science Letters》2008,270(3-4):251-257
New analyses reveal two intervals of distinctly lower δ13C values in the terrestrial organic matter of Permian–Triassic sequences in northern Xinjiang, China. The younger negative δ13Corg spike can be correlated to the conspicuous and sharp δ13C drops both in carbonate carbon and organic carbon near the Permian–Triassic event boundary (PTEB) in the marine section at Meishan. The geochemical correlation criteria are accompanied by a magnetic susceptibility pulse and higher abundances of distinctive, chain-like organic fossil remains of Reduviasporonites.The older negative δ13Corg spike originates within a latest Permian regression. Significant changes in organic geochemical proxies are recorded in the equivalent interval of the marine section at Meishan. These include relatively higher concentrations of total organic carbon, isorenieratane, C14–C30 aryl isoprenoids and lower ratios of pristane/phytane that, together, indicate the onset of anoxic, euxinic and restricted environments within the photic zone. The massive and widespread oxidation of buried organic matter that induced these euxinic conditions in the ocean would also result in increased concentrations of 13C-depleted atmospheric CO2. The latest Permian environmental stress marked by the older negative δ13Corg episode can be correlated with the distinct changeover of ostracod assemblages and the occurrences of morphological abnormalities of pollen grains. These observations imply that biogeochemical disturbance was manifested on the land at the end of the Permian and that terrestrial organisms responded to it before the main extinction of the marine fauna. 相似文献
13.
Paul Farrimond 《中国科学D辑(英文版)》2004,47(5)
Gaseous components of gas inclusions in deep carbonate rocks (>5700 m) from the Tacan 1 well were analyzed by online mass spectrometry by means of either the stepwise heating technique or vacuum electromagnetism crushing. The carbon isotopic compositions of gases released by vacuum electromagnetism crushing were also measured. Although the molecular compositions of gas inclusions show differences between the two methods, the overall characteristics are that gas inclusions mainly contain CO2, whilst hydrocarbon gases, such as CH4, C2H6 and C3H8, are less abundant. The content of CO is higher in the stepwise heating experiment than that in the method of vacuum electromagnetism crushing, and there are only minor amounts of N2, H2 and O2 in gas inclusions. Methane δ13C values of gas inclusions in Lower Ordovician and Upper Cambrian rocks (from 5713.7 to 6422 m; -52‰-63‰) are similar to those of bacterial methane, but their chemical compositions do not exhibit the dry character in comparison with biogenic gases. These characteristics of deep gas inclusions may be related to the migration fractionation. Some deep natural gases with light carbon isotopic characteristics in the Tazhong Uplift may have a similar origin. The δ13C1 values of gas inclusions in Lower Cambrian rocks (7117-7124 m) are heavier (-39‰), consistent with highly mature natural gases. Carbon isotopic compositions of CO2 in the gas inclusions of deep carbonate rocks are similar (from -4‰ to -13‰) to those of deep natural gases, indicating predominantly an inorganic origin. 相似文献
14.
Source and distribution of lead in the surface sediments from the South China Sea as derived from Pb isotopes 总被引:1,自引:0,他引:1
Rapid economic development in East Asian countries has inevitably resulted in environmental degradation in the surrounding seas, and concern for the environment and its protection against pollutants is increasing. Identification of sources of contaminants and evaluation of current environmental status are essential to environmental pollution management, but relatively little has been done in the South China Sea (SCS). In order to investigate the abundance, distribution, and sources of Pb within the SCS, stable Pb isotopes and their ratios were employed to assess the contamination status and to differentiate between natural and anthropogenic origins of Pb in the surface sediments. The total Pb concentrations in sediments varied from 4.18 to 58.7 mg kg−1, with an average concentration of 23.6 ± 8.9 mg kg−1. The observed Pb isotope ratios varied from 18.039 to 19.211 for 206Pb/204Pb, 15.228 to 16.080 for 207Pb/204Pb, 37.786 to 39.951 for 208Pb/204Pb, 1.176 to 1.235 for 206Pb/207Pb, and 2.468 to 2.521 for 208Pb/207Pb. The majority of these ratios are similar to those reported for natural detrital materials. Combined with Pb enrichment factor values, our results show that Pb found within most of the SCS sediments was mainly derived from natural sources, and that there was not significant Pb pollution from anthropogenic sources before 1998. Further studies are needed to reconstruct deposition history and for trend analysis. 相似文献
15.
Young-Joo Lee 《中国科学D辑(英文版)》2006,49(8):872-880
Serious interest has been directed toward natural gas hydrate as a potential energy resource; factor in global climate change, and submarine geohazard since naturally occurring gas-hydrate deposits were found in the 1960s. Hydrate Ridge, Cascadia convergent mar- gin, is characterized by abundant methane hydrates at and below the seafloor, active venting of fluids and gases, chemosynthetic communities, and some of the highest methane oxidation rates ever found in the ma-rine environment. All of… 相似文献
16.
SHUAI YanHua? ZHANG ShuiChang ZHAO WenZhi SU AiGuo & WANG HuiTong Petroleum Geology Research Central Laboratory Research Institute of Petroleum Exploration Development Beijing China 《中国科学D辑(英文版)》2007,50(2):221-227
The distribution of two formation pathways of biogenic methane, acetate fermentation and reduction of CO2, has been extensively studied. In general, CO2 reduction is the dominate pathway in marine envi- ronment where acetate is relatively depleted because of SRB consuming. While in terrestrial freshwater or brackish environment, acetate fermentation is initially significant, but decreases with increasing buried depth. In this paper, character of biogenic gases is profiled in the XS3-4 well of the Sebei 1 gas field in the Sanhu depression, Qaidam Basin. It indicates that those two pathways do not change strictly with increasing buried depth. CO2 reduction is important near the surface (between 50 m and 160 m), and at the mesozone (between 400 and 1650 m). While acetate fermentation is the primary pathway at two zones, from 160 to 400 m and from 1650 to 1700 m. δ 13C of methane generated in those two acetate fermentation zones varies greatly, owing to different sediment circumstances. At the sec- ond zone (160-400 m), δ 13C1 ranges from ?65‰ to ?30‰ (PDB), because the main deposit is mudstone and makes the circumstance confined. At the fourth zone of the well bottom (1650-1700 m), δ 13C1 is lighter than ?65‰ (PDB). Because the deposit is mainly composed of siltstone, it well connects with outer fertile groundwater and abundant nutrition has supplied into this open system. The high con- centration of acetate is a forceful proof. δ 13C of methane would not turn heavier during fermentation, owing to enough nutrition supply. In spite of multi-occurrence of acetate fermentation, the commercial gas accumulation is dominated by methane of CO2-reduction pathway. A certain content of alkene gases in the biogenic gases suggests that methanogensis is still active at present. 相似文献
17.
本文概述了中国南方碳酸盐岩地区的油气勘探经历和认识过程.在刘光鼎院士提出的"油气资源二次创业"理论方法指导下,我国在海相碳酸盐岩地区开展的地球物理勘探工作取得了重要成果.海相碳酸盐岩地区具有更复杂的地质构造和演化过程,该类地区寻找油气是世界性难题,传统勘探手段已不适用.本文给出了该类地区进行地球物理勘探的新思路、新方法、新技术,并以举世瞻目的普光大气田的发现说明了新方法的合理性和优势.文章最后给出在南方海相碳酸盐岩地区进行油气地球物理勘探的发展远景. 相似文献
18.
《中国科学D辑(英文版)》2008,(Z1)
The Xushen gas field,located in the north of Songliao Basin,is a potential giant gas area for China in the future.Its proved reserves have exceeded 1000×10 8 m 3 by the end of 2005.But,the origin of natural gases from the deep strata is still in debating.Epimetamorphic rocks as a potential gas source are widely spreading in the northern basement of Songliao Basin.According to pyrolysis experiments for these rocks in the semi-confined system,gas production and geochemistry of alkane gases are discussed in this paper.The Carboniferous-Permian epimetamorphic rocks were heated from 300℃to 550℃,with temperature interval of 50℃.The gas production was quantified and measured for chemical and carbon isotopic compositions.Results show thatδ13C 1 is less than?20‰,carbon isotope trend of alkane gas isδ13C 1 <δ13C 2 <δ13C 3 orδ13C 1 <δ13C 2 >δ13C 3 ,these features suggest that the gas would be coal-type gas at high-over maturity,not be inorganic gas with reversal trend of gaseous alkanes (δ13C 1 >δ13C 2 >δ13C 3 ).These characteristics of carbon isotopes are similar with the natural gas from the basin basement,but disagree with gas from the Xingcheng reservoir.Thus,the mixing gases from the pyrolysis gas with coal-typed gases at high-over maturity or oil-typed gases do not cause the reversal trend of carbon isotopes.The gas generation intensity for epimetamorphic rocks is 3.0×10 8 ―23.8×10 8 m 3 /km 2 ,corresponding to Ro from 2.0%to 3.5%for organic matter. 相似文献
19.
The Ediacaran period is characterized by the extremely negative carbon isotope anomalies and great biotic evolution in Earth history. At least four negative carbon isotope anomalies have been reported from this interval in South China so far. It is traditionally argued that the isotope variations can be used as a useful tool for global correlation of Ediacaran succession; however, more and more researches argued against this idea. We reviewed the previously published carbon isotope data in South China, and ... 相似文献
20.
WANG XianBin GUO ZhanQian TUO JinCai GUO HongYan LI ZhenXi ZHUO ShengGuang JIANG HongLiang ZENG LongWei ZHANG MingJie WANG LianSheng LIU ChunXue YAN Hong LI LiWu ZHOU XiaoFeng WANG YongLi YANG Hui & WANG Guang Key Laboratory of Gas Geochemistry Chinese Academy of Sciences Lanzhou China Daqing Oilfield Company Ltd. Daqing 《中国科学D辑(英文版)》2009,52(2):213-226
This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mecha- nisms and from different sources in nature. It is demonstrated that the biodegradation or thermode- gradation of complex high-molecule sedimentary organic material can form microbial gas or thermogenic gas. The δ 13C1 value ranges from -110‰ to -50‰ for microbial gases but from -50‰ to -35‰ (even heavier) f... 相似文献