河南省孟州市石庄生油岩特点及潜力分析

河南省孟州市石庄位于济源盆地东南缘,地层属华北地层区山西分区太行山小区。出露的主要地层有中生界三叠系、新生界第三系、第四系。中生代经历了长期陆相湖盆沉积阶段,岩石中有机物含量高。所以该区中生界地层一直作为煤系地层并进行了煤矿资源的勘查工作。本文通过对中生界上三叠统谭庄组的灰黑色岩系取样分析研究,认为该区上三叠统谭庄组为一套含生油岩地层,是济源盆地东侧生油区。在具备一定的运移、储集及盖层等地质条件下可以形成一定规模的油气资源。为今后在河南西北济源盆地寻找油气资源提供了启示。     

中尺度流域次降雨洪水过程模拟——以太湖上游西苕溪流域为例

古近系沙河街组是阳信洼陷最重要的生烃层段.其湖盆充填具阶段性和沉积演化的旋回性,形成了由沙四段、沙三段与沙一段组成的复合生烃系统和不同的地球化学特征.利用Rock-Eval生油岩评价仪、色谱-质谱仪等实验分析技术对不同层系样品进行了地球化学特征分析研究,其中生烃潜力指标包括有机碳含量(TOC)、残余生烃潜量(S1 S2)、氢指数IH、氯仿沥青"A";成熟度指标包括热解峰温Tmax、奇偶优势参数OEP、饱和烃轻重比(C21 C22)/(C28 C29)及∑C21-/∑C22 、镜质体反射率Ro、莫烷/藿烷及甾烷生物标志物参数C29ββ(ββ αα)、C29ααα20S(20S 20R);古环境指标包括异构烷烃参数Pr/Ph、Pr/n-C17、Ph/n-C18及伽马蜡烷等.结果表明,沙四段为弱还原-还原性的半深湖沉积,沉积了一套中等厚度、分布局限的烃源岩(TOC平均为1.5%),其较深位置的烃源岩基本进入成熟阶段,多形成成熟油;沙三段属弱还原-还原性的半深湖-深湖环境,其烃源岩中有机质丰度较高(TOC平均为3.5%),大部分烃源岩处于未成熟-低成熟状态,主要形成未熟油;沙一段为湖水咸化、还原性的半深湖相环境,其烃源岩中有机质丰度高(TOC平均为5%左右),但处于未成熟阶段,主要生成生物气.     

Paleo-productivity evolution across the Permian-Triassic boundary and quantitative calculation of primary productivity of black rock series from the Dalong Formation,South China

The change of the primary productivity across the Permian-Triassic boundary(PTB)remains controversial.In this study,records from two deep-water sections in South China(Xiakou and Xinmin sections)show the primary productivity decreased gradually from the latest Permian to the earliest Triassic,and five evolutionary stages Increase-Decrease-Recovery-RecessionStagnation)can be observed from Clarkina changxingensis-C.deflecta to Hindeodus parvus-Isarcicella isarcica zones.Primary productivity decreased abruptly from the base of C.meishanensis zone.Besides,for adjusting to the deterioration of the oceanic environment,the primary producers in the oceanic surface had changed to acritarch and cyanobacteria,which were more tolerant of stressful environment.Then the producers were under huge stagnation in the H.parvus-I.isarcica zone.The values of quantitative calculation of the primary productivity from the black rock series in the Dalong Formation were very high,corresponding to that of an upwelling area in modern ocean,which shows that the strata of the Dalong Formation in the study region are potential hydrocarbon source-rocks.This result may come from the fact that South China craton was located at the equatorial upwelling area during the Permian-Triassic transitions.But organic matter contents were different in various sections because they could be affected by redox conditions and diagenesis process after burial.     

Early diagenetic growth of carbonate concretions in the upper Doushantuo Formation in South China and their significance for the assessment of hydrocarbon source rock

Mineralogical and textural characteristics and organic carbon composition of the carbonate concretions from the upper Doushantuo Formation (ca. 551 Ma) in the eastern Yangtze Gorge area reveal their early diagenetic (shallow) growth in organic-rich shale. High organic carbon content (up to 10%) and abundance of framboidal pyrites in the hosting shale suggest an anoxic or euxinic depositional environment. Well-preserved cardhouse clay fabrics in the concretions suggest their formation at 0-3 m burial depth, likely associated with microbial decomposition of organic matter and anaerobic oxidation of methane. Gases through decomposition of organic matter and/or from methanogenesis created bubbles and cavities, and anaerobic methane oxidation at the sulfate reduction zone resulted in carbonate precipitation, filling in bubbles and cavities to form spherical structures of the concretions. Rock pyrolysis analyses show that the carbonate concretions have lower total organic carbon (TOC) content but higher effective carbon than those in the host rocks. This may be caused by enclosed organic matter in pores of the concretions so that organic matter was protected from further modification during deep burial and maintained high hydrocarbon generating potential even in over-matured source rock. As a microbialite sensu latu, concretions have special growth conditions and may provide important information on the microbial activities in depositional and early burial environments.     

Geobiological processes of the formation of lacustrine source rock in Paleogene

Gypsum-salt rocks and coccolith calcareous shale are widely deposited in the lower part of the Paleogene Shahejie Formation in the Dongying Sag,Shandong Province.The gypsum-salt rock is believed to be formed during the earlier deposition in salt lake,while the overlying coccolith shale in saline lake with relatively low salinity.By comparing the lake environment and lacustrine microbial communities between ancient and recent lakes,cyanobacteria are regarded as the main representative of productivity during the formation of gypsum-salt strata series,with the annual productivity of 1500-2000 gC m-2 yr-1.Based on the research of ultramicrofossils in the calcareous shale,coccolith is considered as the main contributor to the productivity during the formation of calcareous shale.On the basis of statistic data of sedimentary rates,shale laminations,and coccolith fossils in each lamination,the quantitative value of productivity is calculated,with the annual productivity of 2250-3810gC m-2 yr-1(averagely 3120 gC m-2 yr-1).Statistic data of large amount of pyrite framboids indicate that the lower water column was persistently in sulfidic or anoxic conditions during the deposition of gypsum-salt strata series,but it changed to be dysoxic when the coccolith calcareous shale was deposited.Both of these water conditions are favorable for the preservation of organic matter.It is estimated that the organic carbon burial efficiency of the Lower Paleogene salt lakes and saline lakes of Dongying Depression is about 10%-15%,which is calculated and analyzed using the multi-parameter geobiological model.     

Sr-Nd isotopic compositions of the Changjiang sediments: Implications for tracing sediment sources

The suspended particulate and fine-grained floodplain sediments were collected from the main stream and tributaries of the Changjiang River for Sr-Nd isotopic measurements. The εNd(0) values gradually decrease downstream from -10.8 on average in the upper reaches to -12.3 in the lower reaches, whereas the 87Sr/86Sr ratios increase correspondingly, averaging 0.721899 and 0.725826 respectively in the upper and middle-lower reaches. The compositional variations primarily reflect the complex con- trols of provenance rocks, chemical weathering, and sediment characters between different catchments, among which the abnormal Sr-Nd isotopic compositions of the Yalong, Fujiang, Tuojiang and Yuanjiang rivers indicate the sediment provenance contributions from the Emeishan Basalt in the upper reaches and the old metamorphic and siliceous rocks in the middle-lower reaches. The Sr-Nd isotopic ratios of the Changjiang sediments can better reflect the average composition of weathered continental crust compared to other major rivers in the world because of the unique source rock types in the Changjiang drainage basin. The recognition of the Sr-Nd isotopic systematics of the Changjiang sediments will contribute to our understanding of the Changjiang evolution history and continental weathering processes during the Cenozoic, and also to reconstructing the paleoenvironmental changes in East China and the marginal seas.     

Relation between seismic source parameters and mechanical properties of rocks: A case study

This study attempts to determine the relation between source parameters and mechanical properties of the rock matrix in which the microseismic events occur. For this purpose, accurate geological, mechanical and seismological data were acquired on a gas field experiencing induced seismicity due to its reservoir pressure drop. More than 30 deep boreholes (depth greater than 4 km) are concentrated in a 10×10×5 km volume, providing core samples for both geological and mechanical assessment. In this study, we focus on induced seismic events recorded by the local seismic network, over a three-year-long period. Characteristics of the seismic sources were obtained using spectral analysis and a dynamic model of failure. Results point out correlation between physical parameters of the seismic sources and the geomechanical properties of the rocks involved. Maximal static stress drops are found to be associated with the mechanical strength of the geological strata where the rupture occurs. The fracture size, using a circular model of failure, is also found to be dependent on the geomechanical setting. It is found that the size of the seismic fractures is dependent on the layer thickness and the prefracturation of the medium, both factors influencing the extension of preexisting discontinuities. The parameters of the seismic sources also show important changes when the gas reservoir is reached. The reservoir unit experienced a 45 MPa pore fluid pressure drop over a period of 20 years.     

Geochemical characteristics and accumulation of marine oil and gas around Halahatang depression,Tarim Basin,China

There exists a petroleum system rich of oil and gas around Halahatang depression,where the oil and gas possess obvious local distinctions of properties in different parts.The research proved that the discovered crude oil and natural gas in the region derived mainly from O2 3 source rock,and the differences of its properties were controlled by the oil and gas filling intensity.The comprehensive study result shows the oil and gas reservoirs of the region mainly underwent three important accumulation phases:late Caledonian-Early Hercynian epoch,late Hercynian epoch,and Yanshan-Himalayan epoch. In the first phase,the oil and gas derived mostly from Cambrian source rock,which formed the primary ancient oil reservoirs,then suffered strong degradation and remained a great quantity of pyrobitumen in the high position of Tabei uplift in the present.In the second phase,the O2 3 source rock of Manjia'er depression started its generation of hydrocarbon,which accumulated in the high position of Tabei uplift afterwards,and then biodegradated to heavy oil in the late Hercynian epoch.In the last phase,the O2 3 source rock of southern Halahatang depression and margin of Manjia'er depression started its peak of generating liquid hydrocarbon,which mostly accumulated in the trap formed before the Indo-China and Yanshan epoch,and in somewhere the heavy oil suffered dilutions in various degrees or serious gas invading,to lead to obvious crude oil divergence.     

Development of site-specific design ground motions in Western and Eastern North America

This paper presents results recently obtained for generating site-specific ground motions needed for design of critical facilities. The general approach followed in developing these ground motions using either deterministic or probabilistic criteria is specification of motions for rock outcrop or very firm soil conditions followed by adjustments for site-specific conditions. Central issues in this process include development of appropriate attenuation relations and their uncertainties, differences in expected motions between Western and Eastern North America, and incorporation of site-specific adjustments that maintain the same hazard level as the control motions, while incorporating uncertainties in local dynamic material properties. For tectonically active regions, such as the Western United States (WUS), sufficient strong motion data exist to constrain empirical attenuation relations for M up to about 7 and for distances greater than about 10–15 km. Motions for larger magnitudes and closer distances are largely driven by extrapolations of empirical relations and uncertainties need to be substantially increased for these cases.

For the Eastern United States (CEUS), due to the paucity of strong motion data for cratonic regions worldwide, estimation of strong ground motions for engineering design is based entirely on calibrated models. The models are usually calibrated and validated in the WUS where sufficient strong motion data are available and then recalibrated for applications to the CEUS. Recalibration generally entails revising parameters based on available CEUS ground motion data as well as indirect inferences through intensity observations. Known differences in model parameters such as crustal structure between WUS and CEUS are generally accommodated as well. These procedures are examined and discussed.     

Catalytic decarboxylations of fatty acids in immature oil source rocks

More attention has been paid to the formation conditions of petroleum and gas[1,2]. It is gen-erally accepted that various types of organic materials have served as the most important source of petroleum and gas in sediments. The formation of hydrocarbons…     

重论"上生下储"与"侧向运移"

油气运移是油气藏形成与分布研究的基础．随着生油层理论的建立和发展,油气“上生下储”与“侧向运移”已经成为解释生油层与储集层关系的金科玉律．随着世界范围内油气勘探实践的积累和油气形成与分布研究,特别是对基岩油气藏勘探研究的不断深入,上述运移途径需要重新加以认识。     

声波测井资料地质应用的某些实例及探索

本文用正演方法讨论的问题有:声波速度（或声波时差）在断层附近的异常;用声阻抗信息研究生油泥岩的性能;地层压力的估算方法及地层压力数值在研究古地应力场及地质构造中的应用.     

1999年度中俄合作岩石破裂实验研究

１９９９年１１月～１２月,俄罗斯科学院圣彼得堡Ｉｏｆｆｅ技术物理研究所Ｖ．Ｓ．Ｋｕｋ－ｓｅｎｋｏ教授等专家应邀来华,与中国地震局地球物理研究所和中国科学院地球物理研究所合作,在震源物理实验室开展分米级尺度岩石破裂实验研究。实验中采用了ＳＤＡＥ－８型系统,进行声发射地定位和实时显示。实验采用了多种典型构造模拟和加－卸载方式,取得了丰富的成果。该实验开辟了国际间实质性合作的新途径。     

辽河坳陷大民屯凹陷三台子地区下第三系碎屑岩储层预测研究

针对目标区下第三系储层横向变化快,沉积特征不明显等特点,为提高滚动探井、开发井的钻探成功率,本文研制形成一套具有针对性的油气藏勘探预测研究方法.即运用多井约束波阻抗地震反演方法来预测砂体展布,同时对生成的地震波阻抗反演数据体中的振幅、厚度等暗含的有效信息进行提取,对砂体的分布范围及厚度变化进行准确而精细的描述和预测,最终依据此法优选有利相带,部署井位,取得了很好的勘探开发效果.     

Analysis of mining-induced microseismic events at Strathcona Mine,Subdury, Canada

Rockbursts and mining-induced seismic events have serious socio-economic consequences for the Canadian mining industry, as their mines are extended to greater depths. Automatic multichannel monitoring systems (Electro-Lab MP250s) are routinely, used to detect the arrival times of seismic waves radiated by mining-induced events and sensed on an array of single component transducers installed throughout a mine. These arrival times are then used to locate the events and produce maps of areas of high activity for use in mine planning and design. This approach has limitations in that, it does not allow a detailed analysis of source mechanisms, which could be extracted if whole waveform signals are recorded and analyzed.A major research project, sponsored by the Natural Sciences and Engineering Research Council of Canada (NSERC) with the collaboration of the Canadian mining industry, is aimed at enhancing existing mine seismic monitoring technology in Canada, in order to carry out more advanced processing of data to obtain fundamental scientific information on mining-induced seismic events This paper describes preliminary results from seismic monitoring experiments carried out in a hard rock nickel mine in Sudbury, Canada. Existing seismic monitoring instrumentation was enhanced with a low cost microcomputer-based whole waveform seismic acquisition system. Some of the signals recorded during this experiment indicate anisotropic wave propagation through the mine rock masses, as observed by the splitting of shear waves and the relative arrival of two shear waves polarized in directions which may be related to the structural fabric and/or state of stress in the rock mass. Analysis of compressional wave first motion shows the predominance of shear events, as indicated by focal mechanism studies and is confirmed by spectral analysis of the waveforms. The source parameters were estimated fro typical low magnitude localized microseismic events during the initial monitoring experiments. The seismic moment of these events varied between 10⁶ N.m and 2.10⁸ N.m. with a circular source radius of between 1 m and 2 m with an estimated stress drop of the order of 1 MPa.     

Source area and seasonal 87Sr/86Sr variations in rivers of the Amazon basin

We report the results of a detailed study of dissolved Sr isotopes in the Solimões and Beni‐Madeira Rivers of the Amazon basin. This study developed data collected over 8 years indicating large spatial and temporal variations in dissolved Sr isotopes among the rivers of the Amazon basin. The large ⁸⁷Sr/⁸⁶Sr variations were found to be correlated with the geology of the source areas of the suspended sediments. The Beni‐Madeira River displays a high average ⁸⁷Sr/⁸⁶Sr ratio and large ⁸⁷Sr/⁸⁶Sr fluctuations during the hydrological cycle. This large average value and fluctuations were related to the presence of Precambrian rocks and Ordovician sediments in the source area of the suspended sediment of the river. In contrast, the Solimões River displays a narrow range of Sr isotope ratio variations and an average value close to 0.709. This river drains mostly Phanerozoic rocks of northern Peru and Ecuador that are characterized by low Sr isotope ratios. The isotopic fluctuations in the Beni‐Madeira River were observed to propagate downstream at least as far as Óbidos. This signal is characterized by an inverse relationship between the concentration of elemental Sr and its isotopic ratios. We further demonstrate that the Sr isotopic composition and content in the Beni‐Madeira River is controlled by suspended sediments derived from the Andes. Despite draining areas underlain by Precambrian rocks and having high ⁸⁷Sr/⁸⁶Sr ratios, such rivers as the Negro and Tapajós play a minor role in the total Sr budget of the Amazon basin. Copyright © 2013 John Wiley & Sons, Ltd.     

Cracking conditions of crude oil under different geological environments

There are mainly 3 kinds of existing states of oil generating from source rocks,that is,dispersive liquid hydrocarbon inside of source rock,dispersive liquid hydrocarbon outside of source rock and concentrated liquid hydrocarbon outside of source rock.Because of the differences in thermal history and medium conditions around,and the interaction of organic and inorganic matter,the liquid hydrocarbon with 3 kinds of existing state has different cracking conditions.The gas generation dynamics experiments of crude oil matching different mediums indicate that the distribution of activation energy of methane changes a lot according to medium difference.The carbonate has a main influence on oil cracking conditions and can largely reduce its activation energy,which reflects the lower cracking temperature of crude oil.The mudstone takes a second place and the sandstone is the smallest.The catalytic cracking function to the oil of the carbonate,of the mudstone and of the sandstone changes weaken in turn.The corresponding Ro values of main gas generation period in different mediums are as follows:1.5%―3.8%with pure crude oil,1.2%―3.2%with dispersive crude oil in carbonate,1.3%~3.4% with dispersive crude oil in mudstone and 1.4%―3.6%with dispersive crude oil in sandstone.The influence of pressure to crude oil cracking is relatively complicated.In the low heating speed condition, pressure restrains the oil cracking and gas generation,but in the high heating speed condition,pressure has an indistinctive influence to the oil cracking and gas generation.Pressure also makes a different effort in different evolvement stage.Taking the middle and lower Cambrian source rocks in the Tarim Basin as an example,primary oil generating quantity is 2232.24×10 8 t,residual oil and oil cracking gas quantity is 806.21×10 8 t and 106.95×10 12 m 3 respectively.     

Occurrence, thermal evolution and primary migration processes derived from studies of organic matter in the Lucaogou source rock at the southern margin of the Junggar Basin, NW China

The Lucaogou Formation carbonate-rich oil shale source rock is exposed at the southern margin of the Junggar Basin, Xinjiang, NW China. We have sampled it in detail and conducted microstructural, mineralogical and geochemical studies, including thin section petrography, UV fluorescence petrography, X-ray diffraction, vitrinite reflectance, bitumen reflectance, fluid inclusion analysis and Raman spectroscopy. Organic matter is disseminated through the carbonate-bearing siltstone source rocks and concentrated in numerous bedding parallel stylolites and in two sets of carbonate veins, one along bedding parallel fractures and the other cross-cutting stylolites and bedding. The research about maturity of organic matter finds vitrinite reflectance values increase from the dispersed kerogen (0.64%) to the stylolites (the one of oriented vitrinite is 0.72% and the one of migrated bitumen is 2.38%); Homogenization temperatures of fluid inclusions in veins containing hydrocarbon fluid inclusions show an increase from 178.5℃ in the bedding parallel veins to 222℃ in the cross-cutting veins, confirmed by Raman spectroscopy. These results support a model of progressive heating accompanied by fluid loss during later stages of thermal maturation of source rock and the onset of primary migration. Obviously, the occurrence of organic matter is the trace of hydrocarbon primary migration, and the bedding lamination surfaces and cross-cutting fissures are the principal pathways of hydrocarbon-bearing fluids migration. Bedding lamination surfaces evolved into stylolites along the earliest primary migration pathways, followed by bedding parallel and cross-cutting fissures.     

On the development mechanism of the lacustrine high-grade hydrocarbon source rocks of Chang 91 member in Ordos Basin

As revealed from recent drilling and organic geochemical testing and research, a series of lacustrine high-grade hydrocarbon source rocks was discovered in the upper section of the Chang 9 oil reservoir member of upper Triassic in Ordos Basin. The hydrocarbon source rocks show average TOC content as high as 5.03%, average bitumen "A" content as high as 0.8603%, and good quality organic precursors, which are of the sapropelic type mainly derived from lower aquatic plants and have reached the thermal evolution stage featured by oil-producing climax. Generally the lacustrine high-grade hydrocarbon source rocks were developed in local depressions of a lake basin, and the Chang 91 member was particularly formed in a depositional environment characterized by fresh water to weakly saline water, weakly oxidizing to weakly reducing setting and semi-deep lake facies, as was demonstrated by a variety of organic to inorganic geochemical parameters. As a result, high productivity constitutes the principal controlling force for generation of this series of high-grade hydrocarbon source rocks. Deposition of thinly-bedded and laminated tuffs as well as positive Eu anomaly corroborate the possible occurrence of anoxic geological event closely related to contemporaneous volcanic eruption, which would play a key part in development of the Chang 91 member of high-grade hydrocarbon source rocks.     

岩浆岩和变质岩边坡岩体结构类型的划分

在研究岩浆岩和变质岩特点的基础上,根据岩浆岩岩体结构体的大小、有无缓倾的结构面及岩浆岩散粒状边坡岩体的特征,将岩浆岩边坡岩体结构划分为4大类7个亚类;根据部分正变质岩边坡岩体结构与岩浆岩边坡岩体结构类似,部分副变质岩中发育的板理、千枚理、片理类似沉积岩中的层理,以及边坡岩体具有似层状岩体结构的特征,把变质岩边坡岩体的结构划分为5大类11个亚类。岩体结构的划分为边坡稳定性研究、边坡病害治理及其工程效果评价提供了依据。