Chief Editor:HOU Zengqian
Governing Body:China Association for Science and Technology
Organizer:Geological Society of China
start publication :1922
ISSN:ISSN 1000-9515
CN:CN 11-2001/P
- Most Read
- Most Cited
- Most Downloaded
LIANG Xinquan , LI Xianhua , QIU Yuanxi Guangzhou Institute of Geochemistry , Chinese Academy of Sciences , Guangzhou , Guangdong Geoscience Department , Zhongshan University , Guangzhou , Guangdong
2004, 78(3).
Abstract:Sedimentary response to an orogenic process is important for determining whether South China had compressional or extensional orogeny during the period from the Late Permian to the Middle Triassic besides the tectonic and magmatologic evidence. An intracontinental collision event took place between the Yangtze and Cathaysia blocks in the Late Permian. Beginning at the Late Triassic, the tectonic movement was completely changed in nature and entered a post-collisional extensional orogenic and basin-making process. This paper presents sedimentological evidence from the Late Permian to the Middle Triassic in the Shiwandashan basin at the southwestern end of the junction zone between the Yangtze and Cathaysia blocks.
XIA Xuehui , DONGYE Moxing , ZHANG Zhuo Geological Institute , Bureau of Geology , Mining of China Chemical Industry , Zhuozhou , Hebei , China Department of Biology , Yunnan University , Kunming , Yunnan , China
2004, 78(3).
Abstract:Dianchi Lake is one of the lakes with the richest phosphorus source in the world, in which the P2O5 content in the bottom sediments reaches averagely 0.51 wt % and maximally 1.92%. Studies indicate that this: extremely P-rich state is attributed mainly to the large volume (as high as hundred thousands of tons) of phosphatic matter coming into the lake as many rivers feeding the lake pass through a vast area of phosphate-mining districts, which then undergo weathering and particularly some human activities, including waste water discharge. When phosphatic matter enters the lake, its grained parts are firstly decomposed by phosphorus-decomposing bacteria, and finally accumulated in some geographically special parts of the lake, such as a bay area where water flow is much more slower than elsewhere in the lake. With the involvement of phosphorus-concentrating bacteria, the accumulated phosphates in the bottom sludge ultimately form phosphate minerals through deep-burial diagenesis.
MENG Xianghua , GE Ming , LIU Yanxue , KUANG Hongwei , LIU Weifu , Francoise G. BOURROUILH-LE JAN , Robert BOURROUILH Institute of Sedimentary Basins , China University of Geosciences , Beijing Chinese Academy of Geological Sciences , Beijing Department of Geophysics , Yangzi University , Jingzhou , Hubei Laboratoire Cibamar , Universite Bordeaux , Avenue des Facultes , TALENCE Cedex , France
2004, 78(3).
Abstract:Based on a study of Neoproterozoic carbonates in the Jilin-Liaoning-Xuzhou-Huaiyang area, especially its cyclic sequence stratigraphy and Sr isotopes, two maximum sea flooding events (at 820 Ma and 835 Ma) have been identified. The resulting isochronous stratigraphic correlation proves that these Precambrian strata were connected between the Qingbaikou and the Nanhuan systems with a time range from 750 Ma to 850 Ma. The disappearance of microsparite carbonate and coming of a glacial stage offer important evidence for worldwide stratigraphic correlation and open a window for further correlation of the stratigraphic successions across the Sino-Korean and Yangtze Plates. A new correlation scheme is therefore provided based on our work.
GE Ming , KUANG Hongwei , MENG Xianghua , George FURNISS Institute of Sedimentary Basin , China University of Geoscience , Xueyuan Road , Beijing , China Yangzi University , Nanjing , Jiangsu , China Geology Department , University of Montana , Missoula , Montana , USA
2004, 78(3).
Abstract:Molar-tooth carbonate refers to a sort of rock that has ptygmatical folded structure comparable to the ivory. This kind of carbonate exists in a special time range (from Middle to Neoproterozoic). Its origin and the possibility to use it in stratigraphic correlation of the paleocontinent is the key task of the IGCP447, a project on Proterozoic molar tooth carbonates and the evolution of the earth (2001-2005). The importance lies in that the molar-tooth structure is the key to solving problems related to Precambrian biological and global geochemical events. The molar-tooth structure is associated with microorganisms. Development and recession of such carbonates have relations with the evolution process of early lives and abrupt changes in sea carbonate geochemistry. In recent years, based on researches on petrology, geochemistry and Sr isotope of molar-tooth carbonate in the Jilin-Liaoning and Xuzhou-Huaiyang area, the authors hold that it can be used as a marker for stratigraphic sequence and sedimentary fades analyses.
WEI Haiquan , HONG Hanjing , R.S.J. SPARKS , J.S. WALDER , HAN Bin Institute of Geology , China Seismological Bureau , Beijing , Department of Earth Sciences , Bristol University , UK Cascades Volcano Observatory , US Geological Survey , USA
2004, 78(3).
Abstract:Since the eruption of the Tianchi volcano about 1000 years ago, there have been at least 3 to 5 eruptions of small to moderate size. In addition, hazardous avalanches, rock falls and debris flows have occurred during periods between eruptions. A future eruption of the Tianchi volcano is likely to involve explosive interaction between magma and the caldera lake. The volume of erupted magma is almost in a range of 0.1-0.5 km3. Tephra fallout may damage agriculture in a large area near the volcano. If only 1% of the lake water were ejected during an eruption and then precipitated over an area of 200 km2, the average rainfall would be 100 mm. Moreover, lahars are likely to occur as both tephra and water ejected from the caldera lake fall onto flanks of the volcano. Rocks avalanching into the caldera lake also would bring about grave hazards because seiches would be triggered and lake water with the volume equal to that of the landslide would spill out of the existing breach in the caldera and cause flooding downstream.
ZHENG Mianping , QI Wen , JIANG Xianfeng , ZHAO Yuanyi , LI Minghui Open Laboratory of Saline Lake Resources , Environment , Chinese Academy ofGeological Sciences , Beijing R & D Center for Saline Lakes , Epithermal Deposits , Chinese Academy of Geological Sciences , Beijing
2004, 78(3).
Abstract:Salt lakes are a mirror of climatic changes and provide holographic records of environmental changes of lakes. According to a study of geological hazards in typical salt lake areas in China and other regions, the authors explain how geological hazards in salt lake areas are caused by natural agents and how humans can seek benefits, avoid hazards and reduce losses on the premise that they have monitored and mastered the trend of salt lake changes in advance and even can store flood and recharge water in lakes and extract saline resources. The climate
JIANG Yuehua , WANG Jingdong , YUAN Xueyin , WANG Runhua China University of Geosciences , Wuhan , Hubei , Nanjing Institute of Geology , Mineral Resources , Nanjing , Jiangsu
2004, 78(3).
Abstract:Geomorphically, Huzhou, which is on the Yangtze River delta is characterized mainly by plains, with small hills. This paper presents a detailed analysis of the environmental geological hazards both natural and those incurred by human activities in different morphologic units. The authors point out that most of the regional environmental geological problems in the natural geologic-morphologic conditions, such as crustal stability, foundation of soft soil, soil waterlogging and soil erosion, have insignificant effects to the society, or related countermeasures of prevention and control have been adopted. But environmental geological problems incurred by human being's economic activities become more and more severe, for example, water and soil pollution and land subsidence in plain areas resulting from overexploitation of groundwater, and landslides, karst collapses and water and soil loss etc. caused by quarrying in hilly areas.
WANG Bingchen , ZHENG Xilai , QIAN Hui , LIN Guoqing , XU Qian Comprehensive Institute of Geotechnical Survey , Beijing Institute of Environmental Science , Engineering , China Ocean University , Qingdao , Shandong Department of Water Resources , Chang''''an University , Xi''''an , Shaanxi
2004, 78(3).
Abstract:According to practical geological and hydrogeological conditions of riverside water-supply well fields in northwestern China, an ideal hydrogeological model has been generalized and a three-dimensional mathematical model has been set up. A finite difference method was applied to simulating groundwater flow near a partially penetrating river under riverside pumping, and to analyzing the effects of river width, partial penetration and permeability of riverbed sediments on groundwater recharges. Results show that riverside pumping may cause groundwater to flow beneath the partially penetrating river, and that river width, penetration and riverbed permeability obviously influence flows from the partially penetrating river and constant-head boundaries. However, the pumping output is mainly from the partially penetrating river.
ZHENG Xilai , WANG Bingchen , LI Yuying , XIA Wenxiang Institute of Environmental Science , Engineering , Ocean University of China , Qingdao , Shandong Comprehensive Institute of Geotechnical Survey , Beijing
2004, 78(3).
Abstract:On the basis of site investigation and sample collection of petroleum contaminants in the soil-water-crop system in the Shenyang-Fushun sewage irrigation area, the physical-chemical-biological compositions of the unsaturated zone is analyzed systematically in this paper. At the same time, the degradation kinetics of residual and aqueous oils is determined through biodegradation tests. The studies show that dominant microorganisms have been formed in the soils after long-term sewage irrigation. The microorganisms mainly include bacteria, and a few of fungus and actinomycetes. After a 110-days' biodegradation test, the degradation rate of residual oil is 9.74%-10.63%, while the degradation rate of aqueous oil reaches 62.43%. This indicates that the degradation rate of low-carbon aqueous oil is higher than that of high-carbon residual oil. In addition, although microbial degradation of petroleum contaminants in soils is suitable to the first-order kinetics equation, the half-lives of aqueous oil, No. 20 heavy diesel and residual oil in the surface soils (L2-1, S1-1 and X1-1) are 1732 h, 3465 h and 17325 h, respectively.
LI Yixiang , GAO Guanhua Department of Land , Resources of Anhui Province , ChinaDepartment of Mines , Energy of Northern Territory , Australia
2004, 78(3).
Abstract:Groundwater is one of the important water resources in northern China's plain areas. Many severe geological hazards have occurred in these areas due to ground subsidence which is caused by over exploitation of groundwater. This paper introduces and analyses the ground subsidence caused by groundwater exploitation and its mechanism in the northern China's plains. A ground subsidence prediction model has been developed based on the consolidation theory. The authors have tested this model in a case study of Fuyang City, Anhui Province, where ground subsidence is a severe environmental problem. In the case study, the model results match very well with those of the actual measurement. Two schemes of groundwater exploitation are assessed. The conclusion from the study could be used in the long-term water and economical management planning. The strategies for the control of ground subsidence are discussed.
YAN Lei , FENG Hao , DENG Zhongliang , GAO Zhengbing Beijing Key Lab of Spatial Information Integration , Its Applications , Institute of RS , GIS , Peking University , Beijing Beijing University of Posts , Telecommunications , Beijing
2004, 78(3).
Abstract:At present, new integrated navigation, which usesthe location function of reference gravity anomaly map to control the errors of the inertial navigation system (INS), has been developed in marine navigation. It is named the gravity-aided INS. Both the INS and real-time computation of gravity anomalies need a 3-D marine normal gravity model. Conventionally, a reduction method applied in geophysical survey is directiy introduced to observed data processing. This reduction does not separate anomaly from normal gravity in the observed data, so errors cannot be avoided. The 3-D marine normal gravity model was derived from the J2 gravity model, and is suitable for the region whose depth is less than 1000 m.
ZHAO Hongying ZHAO Hu , YAN Lei , ZHAO YunshengInstitute of Remote Sensing , GIS , Peking University , Beijing , Beijing Key Lab of Spatial Information Integration , Its Applications , Institute of RS , GIS , Peking University , Beijing Department of Geography , Northeast Normal University , Changchun , Jilin
2004, 78(3).
Abstract:This paper deals with reflection spectra and polarized reflection spectra of 20 sorts of rock in 2π space, and then creates a model of reflection spectra of rock surface in 2π space. We measured the change of reflection and polarized reflection spectra as altering the incidence angle, vertex angle, azimuth angle, band and polarization. The results show that influence of the incidence angle on spectral curves is very strong. And when the vertex angle is constant, the horizontal azimuth polarizes rock spectra, and distorts the circular spectrum to become elliptic. The polarization influences the reflection intensity of rock spectra, but has no evident influence on the characteristics of wave forms of rock in 2π space. Therefore, we can describe the whole reflection spectral characteristics, including polarization, of rock surface in 2π space by measuring and calculating the e and p values in several key directions.
CHEN Daogong , CHENG Hao School of Earth , Space Sciences , University of Science , Technology of China , Hefei , Anhui , School of Ocean , Earth Science , Tongji University , Shanghai
2004, 78(3).
Abstract:For the first time, we apply different geospeedometric models to garnet zoning patterns that were obtained in this study from detailed EMP analyses for garnets from eclogites and granulite in the Dabie-Sulu orogen. Various zonings of cation diffusion were preserved in the garnets, enabling the acquirement of average cooling rates for the high-to ultrahigh-pressure rocks without using geochronological approaches. The coesite-bearing hot eclogites yield fast cooling rates of about 20 to 30℃/Ma subsequent to peak metamorphic temperatures, whereas the cold eclogite gives a relatively slow cooling rate of 8℃/Ma at its initial exhumation. A very slow cooling rate of <0.3℃/Ma is obtained for the granulite at Huangtuling, suggesting that the granulite may not be involved in the continental deep subduction.
ZHAO Ting , ZHAO Xun Institute of Mineral Deposits , Chinese Academy of Geological Sciences , Beijing Chinese Academy of Geological Sciences , Beijing
2004, 78(3).
Abstract:The conservation of geological remains in China, especially in renowned sites with historical or cultural significance, has long been paid attention to. As the urban residents become more interested in returning to and harmony with the nature, tourism related sciences and knowledge gets more attractive. Geosites and geoparks can definitely play an important role to lead this historic tendency.
WANG Chengshan , HUANG Yongjian , HU Xiumian , LI Xianghui State Key Laboratory of Oil/Gas Reservoir Geology , Exploration , Chengdu Universityof Technology , Chengdu , Sichuan and College of Earth Science , Chengdu University of Technology , Chengdu , Sichuan Department of Earth Science , Nanjing University , Nanjing , Jiangsu China University of Geosciences , Beijing
2004, 78(3).
Abstract:The Cretaceous is among the most unusual eras in the geological past. Geoscience communities have been having great concerns with geological phenomena within this period, for example carbonate platforms and black shales in the Early and Middle Cretaceous respectively, during the last decades. But few people have paid any attention to the set of pelagic redbeds lying on the black shales, not to mention the applications to paleoclimatology and paleoceanography. It is shown by the sedimentary records of redbeds, that they were deposited around the CCD, with both a higher content of iron and much lower concentrations of organic carbon, which implies conditions with a relatively high content of oxygen. Such redbeds occurred in the global oceans, mainly in the Tethyan realm, with different durations of deposition and a climax from the late Santonian to early Campanian. Global cooling and dramatic changes in ocean currents might help to increase the oxygen flux between the atmosphere and ocean, after the large scale organic carbon burial during the Middle Cretaceous, and therefore lead to the oxygenation of deep ocean and so the occurrence of late Cretaceous oceanic redbeds.
2004, 78(3).
Abstract:A Taxanomic Study on Primitive EuconodontsWU Guichun, YAO Jianxin and JI Zhansheng(Institute of Geology, Chinese Academy of Geological Sciences,Beijing 100037)Primitive euconodonts are extrmely abundant and varied in the Late Cambrian in western Shandong Province. Two new genera are established, including Camconodontus gen. nov. and Laiwunodus gen. nov. Among them the following species are described: Camconodontus rotundatus gen. et sp. nov., Camconodontus sp., Laiwunodus lateronodus gen. et sp. nov., and
2004, 78(3).
Abstract:1. Papers should be devoted mainly to various aspects of research concerning geosciences and related disciplines in China, such as stratigraphy, paleontology, origin and history of the Earth, structural geology, tectonics, mineralogy, petrology, geochemistry, geophysics, geology of mineral deposits, hydrogeology, engineering geology, environmental geology, regional geology and new theories and technologies of geological exploration. Those of scientific interest to the geological community in China or of international interest are also welcome.
JIANG Fuchu , WANG Shubing , ZHAO Zhizhong , FU Jianli Institute of Geomechanics , Chinese Academy of Geological Sciences , Beijing State Key Laboratory of Loess , Quaternary Geology , Chinese Academy of Sciences , Xi''''an , Shaanxi
2004, 78(3).
Abstract:The Mangshan Yuan is a loess platform on the southern bank of the Yellow River, which is located in northwestern Zhengzhou of Henan Province, China. The typical Zhaoxiayu section of the Mangshan Yuan preserves stratigraphical loess units above S10 with a total thickness of 172.1 m, which includes 15.7 m of the last interglacial paleosol S1, 77.3 m of the last glacial loess L1 that consist of 41.6 m of the late stade L1LL1, 13.2 m of the interstade L1SS1 and 22.5 m of the early stade L1LL2. Based on the age marking points by correlating magnetic susceptibility of the section with the SPECMAP curve, the timescale of the section was constructed, and the average accumulation rate and the resolution of each loess strata over the S2 were subsequently calculated using the
TANG Shuheng , SUN Shenglin , HAO Duohu , TANG Dazhen China University of Geosciences
2004, 78(3).
Abstract:The coalbed methane (CBM) resources in North China amounts up to 60% of total resources in China. North China is the most important CBM accumulation area in China. The coal beds of the Upper Paleozoic Taiyuan and Shanxi formations have a stable distribution. The coal reservoir of target areas such as Jincheng, Yanquan-Shouyang, Hancheng, Liulin, etc. have good CBM-bearing characteristics, high permeability and appropriate reservoir pressure, and these areas are the preferred target areas of CBM developing in China. The coal reservoirs of Wupu, Sanjiaobei, Lu'an, Xinmi, Anyang-Hebi, Jiaozuo, Xinggong and Huainan also have as good CBM-bearing characteristics, but the physical properties of coal reservoirs vary observably. So, further work should be taken to search for districts with high pressure, high permeability and good CBM-bearing characteristics. Crustal stresses have severe influence on the permeability of coal reservoirs in North China. From west to east, the crustal stress gradient increases, while the coal reservoirs permeability decreases.
LIU Chunlian , Wolfgang OSCHMANN , BAI Yan , DONG Yixin , XIE Yecai Department of Earth Sciences , Sun Yat-Sen
2004, 78(3).
Abstract:Analyses of organic carbon, nitrogen, sulfur and iron have been performed in order to understand sources and preservation of organic matter in black shale of the Buxin Formation (Early Paleogene) from the Sanshui Basin. The C/N ratios show that the organic matter is characterized by a mixture of terrestrial and phytoplanktonic contributions. The relative importance of different sources depend on climate conditions and most of organic matter is of terrestrial origin. The relationships between C, S and Fe indicate that the brackish environment with alternation of anoxia and low-O2 developed in the bottom waters during the deposition of these organic-rich sediments as a result of a mixed setting of thermal stratification and salinity stratification, the latter being the consequence of intermittent sea water incursion. Bacterial sulfate reduction is the most effective early diagenesis affecting the preservation of organic matter. The intensity of sulfate reduction is related to the relative proportion of metabolizable organic matter supplied to sediments.
ZHANG Kang , WANG Darui Exploration , Production Research Institute , China Petroleum , Chemical Corporation
2004, 78(3).
Abstract:Almost all the oil and gas reservoirs developed in marine sedimentary strata of China have undergone processes of multi-phase reservoir formation and later modification. The irregular reservoirs are classified into three types as the Naxi, Tahe and Renqiu ones, increasing successively in the development degree of karstificated pores and fissures and the connection degree of independent reservoirs. In these reservoirs, the unity in the fluid feature, pressure and oil-gas-water interface also increases successively from the Naxi to the Renqiu type. The main body of Ordovician reservoirs of the Tahe Oilfield in the Tarim Basin is a network pool rather than a stratified, massive, stratigraphically-unconformed or weathering-crust one. The fluid nature of oil, gas and water, the interface positions and the pressures, as well as the dynamic conditions of fluids within the reservoirs during the production are all different from those in stratified or massive oil and gas reservoirs. Carbonates in the Akekule uplift and the Tahe Oilfield are assemblages of various types of reservoirs, which have an overall oil-bearing potential and obvious uneven distribution. Testing and producing tests are the major means to evaluate this type of reservoirs and acid fracturing improvement is a key link in petroleum exploration and development.
2004, 78(3).
Abstract:The International Geological Congress held every four years is a grand event for displaying the latest achievements in geological science and technology and carrying out academic exchange.After the 31st IGC, the Chinese geologists, like their counterparts in the rest of the world, started to pay more attention to the issues facing the world today, including the shortage of energy and resources, geological hazards, environmental degradation and sustainable socio-economic
PANG Xiongqi , LI Sumei , JIN Zhijun , BAI Guoping Key Laboratory of Hydrocarbon Accumulation , Ministry of Education , Beijing , E-mail: pangxq@bjpeu.edu.cnBasin & Reservoir Research Center , University of Petroleum , Beijing Sinopec Petroleum Exploration , Exploitation Institute , Beijing
2004, 78(3).
Abstract:Based on a detailed survey of the distribution and organic geochemical characteristics of potential source rocks in the South Slope of the Niuzhuang Sag, Bohai Bay Basin, eastern China, a new approach to assess the amount of hydrocarbons generated and expelled has been developed. The approach is applicable to evaluate hydrocarbons with different genetic mechanisms. The results show that the models for hydrocarbon generation and expulsion vary with potential source rocks, depending on thermal maturity, types of organic matter and paleoenvironment. Hydrocarbons are mostly generated and expelled from source rocks within the normal oil window. It was calculated that the special interval (algal-rich shales of the ES4 member formed in brackish environments) in the South Slope of the Niuzhuang Sag has a much higher potential of immature oil generation than the other intervals in the area. This suggests that hydrocarbons can definitely be generated in early diagenesis, especially under certain special geological settings. The proportion of hydrocarbons generated and expelled from the ES4 shales in the early diagenetic stage is up to 26.75% and 17.36%, respectively. It was also observed that laminated shales have a much higher expulsion efficiency than massive mudstones. In contrast, the special interval of the ES4 shales proposed from previous studies is probably not the whole rock for oil in the South Slope of the Niuzhuang Sag because of the small proportion of the gross volume and corresponding low percentage of hydrocarbons generated and expelled. A much lower expulsion efficiency of the source rock during the early stage relative to that within the normal oil window has been calculated. Our results indicate that the ES4 mudstones rather than the shales deposited in the Niuzhuang and Guangli Sag are the main source rocks for the oil discovered.
PANG Xiong , YANG Shaokun , ZHU Ming , LI Jinsong CNOOC China Limited Shenzhen , Guangzhou , Guangdong
2004, 78(3).
Abstract:The shallow shelf delta/strand arenaceous-pelitic deposit region in the north of the Pearl River mouth basin, sitting on the northern continental shelf of the South China Sea, has already become an important oil production base in China. Recent researched has revealed that a great deal of deep-water fans of great petroleum potentiality exist on the Baiyun deep-water slope below the big paleo Pearl River and its large delta. Based on a mass of exploration wells and 2-D seismic data of the shallow shelf region, a interpretation of sequence stratigraphy confirmed the existence of deep-water fans. The cyclic falling of sea level, abundant detrital matter from the paleo Pearl River and the persistent geothermal subsidence in the Baiyun sag are the three prerequisites for the formation and development of deep-water fans. There are many in common between the deep-water shelf depositional system of the northern South China Sea and the exploration hotspots region on the two banks of the Atlantic. For example, both are located on passive continent margins, and persistent secular thermal subsidence and large paleo rivers have supplied abundant material sources and organic matter. More recently, the discovery of the big gas pool on the northern slope of the Baiyun sag confirms that the Lower Tertiary lacustrine facies in the Baiyun sag has a great potentiality of source rocks. The fans overlying the Lower Tertiary source rocks should become the main exploration areas for oil and gas resources.
GONG Zaisheng , ZHANG Gongcheng , CAI Dongsheng , HE Shibin China National Offshore Oil Corporation , Beijing , Research Center of China National Offshore Oil Corporation , Beijing
2004, 78(3).
Abstract:Neotectonism occurred intensively in the Bozhong depression in the Bohai Bay Basin, which was reflected vertically by dramatic subsidence and a number of uplifts and laterally by notable fault movements. This particularity has resulted in the special petroleum geological conditions of the Bozhong depression which are different from those of adjacent lands. For example, the source rocks of the Shahejie Formation were overpressured and hydrocarbon generation occurred in the late stage; the Dongying Formation was deeply buried below the hydrocarbon-generating threshold, therefore there were sufficient oil sources. The rapid subsidence led to starved sedimentation of the Guantao Formation fine sandstone and the regional Minghuazhen Formation lacustrine shale, which formed the Neogene regional reservoir-caprock association. The active faults formed in the neotectonism became passages for oil to migrate from the Paleogene to Neogene. The traps formed by late fault activity and accompanied anticlines provided spaces for the formation of reservoirs. All the above factors match well with one another in the Bozhong depression, providing favorable conditions for the formation of a series of large oilfields in the region
WANG Zhenfeng , XIE Xinong CNOOC Limited-Zhanjiang , Zhanjiang Guangdong , Faculty of Earth Resources , China University of Geosciences , Wuhan , Hubei
2004, 78(3).
Abstract:There are plentiful potential hydrocarbon resources in the Yinggehai and Qiongdongnan basins in the northern South China Sea. However, the special petrol-geological condition with high formation temperature and pressure greatly blocked hydrocarbon exploration. The conventional means of drills, including methods in the prediction and monitoring of underground strata pressure, can no longer meet the requirements in this area. The China National Offshore Oil Corporation has allocated one well with a designed depth of 3200 m and pressure coefficient of 2.3 in the Yinggehai Basin (called test well in the paper) in order to find gas reservoirs in middle-deep section in the Miocene Huangliu and Meishan formations at the depth below 3000 m. Therefore, combined with the '863' national high-tech project, the authors analyzed the distribution of overpressure in the Yinggehai and Qiongdongnan basins, and set up a series of key technologies and methods to predict and monitor formation pressure, and then apply the results to pressure prediction of the test well. Because of the exact pressure prediction before and during drilling, associated procedure design of casing and their allocation in test well has been ensured to be more rational. This well is successfully drilled to the depth of 3485 m (nearly 300 m deeper than the designed depth) under the formation pressure about 2.3 SG (EMW), which indicate that a new step in the technology of drilling in higher temperature and pressure has been reached in the China National Offshore Oil Corporation.
ZHENG Herong , HE Zongquan Petroleum Exploration & Production Research Institute , SINOPEC , Beijing
2004, 78(3).
Abstract:The rift lake basins in the eastern China have abundant hydrocarbon resources of lithologic deposits, which resulted from excellent source rocks and multi-type sandbodies developed during strong rifting. Vertically, the lithologic deposits are mainly distributed in the lowstand, lacustrine invasion and early highstand systems of third-order sequence corresponding to a secondary tectonic episode of strong rifting, and laterally they are closely related to various fans and turbidite sandbodies controlled by syn-sedimentary faults. A variety of lithologic traps have been developed in the rift lake basins, and they generally have favorable conditions of source-reservoir-seal assemblage and hydrocarbon accumulation dynamics, indicating that there is a great exploration potential of lithologic deposits in the rift lake basins. In order to obtain satisfactory effects of lithologic deposit exploration, it is required to combine new theories with advanced technical methods.
WANG Tingbin Petroleum Exploration , Development Research Institute , SINOPEC , Beijing
2004, 78(3).
Abstract:Tectonic movements since the Neogene have been the major developmental and evolutional stages of the latest global crustal deformation and orogenic movements. China is located in a triangular area bounded by the Indian landmass, the West Siberian landmass and the Pacific Plate, characterized by relatively active tectonic movements since the Neogene, and in this region, natural gas would have been very easy to dissipate, or difficult to preserve. Therefore, the characteristics of post-Neogene tectonic movements offer important geological factors in researching the formation and preservation of gas reservoirs in China. Summarizing the reservoiring history of gas fields in China, although there are some differences between various basins, they are all affected by the tectonic
SU Xianbo , LIN Xiaoying , SONG Yan , ZHAO Mengjun Henan University of the Sciences , Jiaozuo , Henan Research Institute of Petroleum Exploration , Development , PetroChina , Beijing
2004, 78(3).
Abstract:Coalbed methane has been explored in many basins worldwide for 30 years, and has been developed commercially in some of the basins. Many researchers have described the characteristics of coalbed methane geology and technology systematically. According to these investigations, a coalbed methane reservoir can be defined: "a coal seam that contains some coalbed methane and is isolated from other fluid units is called a coalbed methane reservoir". On the basis of anatomization, analysis, and comparison of the typical coalbed methane reservoirs, coalbed methane reservoirs can be divided into two classes: the hydrodynamic sealing coalbed methane reservoirs and the self-sealing coalbed methane reservoirs. The former can be further divided into two sub-classes: the hydrodynamic capping coalbed methane reservoirs, which can be divided into five types and the hydrodynamic driving coalbed methane reservoirs, which can be divided into three types. The latter can be divided into three types. Currently, hydrodynamic sealing reservoirs are the main target for coalbed methane exploration and development; self-sealing reservoirs are unsuitable for coalbed methane exploration and development, but they are closely related with coal mine gas hazards. Finally, a model for hydrodynamic sealing coalbed methane reservoirs is established.
WANG Weifeng , CHEN Yequan Earth''''s Resources , Information College , University of Petroleum , Dongying , Shandong Graduate School , Chinese Academy of Sciences , Beijing , Institute of Geochemistry , Chinese Academy of Sciences , Guiyang , Guizhou
2004, 78(3).
Abstract:The Junggar basin is located in the northern part of Xinjiang of China. It is part of the Kazakstan plate, surrounded by the Paleozoic folded mountains: the Halaart, Zayier and Chepaizi Mountains in the northwest, the Qingelidi and Karamaili Mountains in the northeast, and the Tianshan Mountains in the south. In different evolution stages, the basin's types are different, and the stratigraphy and deposition are also different. From the Carboniferous to Tertiary the basin has in turn gone through rift basin, collision foreland basin, intraplate depression basin and regenerated foreland basin. Based on an analysis of thermal evolution history and buried history of the source rocks, three major periods of oil generation are found in the basin. According to the characteristics of source rock distribution, evolution, oil-source correlation, structure and multi-phase and mixed pools, the Junggar basin could be divided into 4 composite petroleum systems. Due to the variation in sedimentary facies, difference in structural patterns and development histories, the petroleum pool-forming conditions in different areas and horizons are greatly different, so are the petroleum pool types, the accumulation mechanisms in different areas and horizons.
YAN Xiangbin , LI Tiejun , ZHANG Tao Exploration , Development Research Institute , SINOPEC , Beijing
2004, 78(3).
Abstract:Ordovician marine carbonate basement traps are widely developed in the paleo-highs and paleo-slopes in the Tarim Basin. Reservoirs are mainly altered pore-cavity-fissure reservoirs. Oil sources are marine carbonate rocks of the Lower Paleozoic. Thus, the paleo-highs and paleo-slopes have good reservoiring conditions and they are the main areas to explore giant and large-scale oil reservoirs. The main factors for their reservoiring are: (1) Effective combination of fenestral pore-cavity-fracture reservoirs, resulting from multi-stage, multi-cyclic karstification (paleo-hypergene and deep buried) and fracturing, with effective overlying seals, especially mudstone and gypsum mudstone in the Carboniferous Bachu Formation, is essential to hydrocarbon reservoiring and high and stable production; (2) Long-term inherited large rises and multi-stage fracture systems confine the development range of karst reservoirs and control hydrocarbon migration, accumulation and reservoiring; (3) Long-term multi-source hydrocarbon supply, early reservoiring alteration and late charging adjustment are important reservoiring mechanisms and determine the resource structure and oil and gas properties. Favorable areas for exploration of Ordovician carbonate basement hydrocarbon reservoirs in the Tarim Basin are the Akekule rise, Katahe uplift, Hetianhe paleo-high and Yakela faulted rise.
LI Sumei , PANG Xiongqi , JIN Zhijun Key Laboratory of Hydrocarbon Accumulation , Ministry of Education , Beijing Basin & Reservoir Research Center , University of Petroleum , Beijing Sinopec Petroleum Exploration , Exploitation Institute , Beijing
2004, 78(3).
Abstract:Recent detailed organic geochemical and geological investigation indicate that oils of the Bamianhe oilfield, Bohai Bay Basin, East China are the mixture of less mature oils and normal oils derived from the ES4 mudstones and shales with a wide range of thermal maturity from immature to middle-maturity, and most of the oils were proved to be sourced from the depocenter of the Niuzhuang Sag immediately adjacent to the Bamianhe oilfield. Two approaches to quantify the amount of immature oils mixed through quantitative biomarkers were established. One is a relatively simple way only through organic geochemical analysis while the other is to be combined with basin modeling. Selecting biomarkers as proxies is the crucial point in both of them. The results show that the less mature oils mixed in the Bamianhe oilfield is less than 10% and 18% respectively based on the two approaches, which coincide with the results of oil-source rock correlation.
TANG Liangjie , JIN Zhijun , JIA Chengzao , PI Xuejun , CHEN Shaping , XIE Huiwen , WANG Ziyu Key Laboratory for Hydrocarbon Accumulation , Ministry of Education , Beijing Basin , Reservoir Research Center , University of Petroleum , Beijing Institute of Petroleum Exploration , Development , SINOPEC , Beijing PetroChina Company Limited , Beijing Tarim Oilfield Company , PetroChina Company Ltd. , Kurle , Xinjiang
2004, 78(3).
Abstract:The tectono-stratigraphic sequences of the Kuqa foreland fold-thrust belt in the northern Tarim basin, northwest China, can be divided into the Mesozoic sub-salt sequence, the Paleocene-Eocene salt sequence and the Oligocene-Quaternary supra-salt sequence. The salt sequence is composed mainly of light grey halite, gypsum, marl and brown elastics. A variety of salt-related structures have developed in the Kuqa foreland fold belt, in which the most fascinating structures are salt nappe complex. Based on field observation, seismic interpretation and drilling data, a large-scale salt nappe complex has been identified. It trends approximately east-west for over 200 km and occurs along the west Qiulitag Mountains. Its thrusting displacement is over 30 km. The salt nappe complex appears as an arcuate zone projecting southwestwards along the leading edge of the Kuqa foreland fold belt. The major thrust fault is developed along the Paleocene-Eocene salt beds. The allochthonous nappes comprise large north-dipping faulting monoclines which are made up of Paleocene-Pliocene sediments. Geological analysis and cross-section restoration revealed that the salt nappes were mainly formed at the late Himalayan stage (c.a. 1.64 Ma BP) and have been active until the present day. Because of inhomogeneous thrusting, a great difference may exist in thrust displacement, thrust occurrence, superimposition of allochthonous and autochthonous sequences and the development of the salt-related structures, which indicates the segmentation along the salt nappes. Regional compression, gravitational gliding and spreading controlled the formation and evolution of the salt nappe complex in the Kuqa foreland fold belt.
LEI Huaiyan , LIU Zhihong , XU Maoquan , GUAN Baocong Institute of Oceanography , Environment , Xiamen University , Xiamen , Fujian State Key Laboratory of Gas Geochemistry , Institute of Geology , Chinese Academy of Sciences , Lanzhou , Gansu
2004, 78(3).
Abstract:There are few 3-D seismic profiles and drillings in the middle part of the Qibei depression in the Dagang oilfield, and more than 70% of the 2-D seismic profiles were completed before the 1980s. Meanwhile, changes in the terrestrial formations in this region have been large and complex. These factors have made it difficult to predict reservoirs in this area. The purpose of this paper is to establish a methodology for predicting potential gas and oil reservoirs. Our research combines sequence stratigraphy, well-logs, and seismic analysis to elucidate the prediction of flagstone reservoirs in the S1 (Sha-I) Member in the middle of the Qibei depression. Previous research indicates that these rocks were deposited in an environment that had a semiarid, northern subtropical, and warm, humid climate. The objective strata currently consist mainly of lake fades, deeper lake facies, and shore-shallow lake facies. The study reveals that the lower section of the S1 Member is an important objective region for exploration.
LIN Chunming , LI Guangyue , WANG Baichang , GU Lianxing , ZHUO Hongchun Department of Earth Sciences , State Key Laboratory of Ore Deposit Research , Nanjing University , Nanjing , Jiangsu
2004, 78(3).
Abstract:This paper presents the sedimentary facies and formation of the Qiantangjiang and Taihu incised valleys, and the characteristics of shallow gas reservoir distribution, based on a large number of data of drilling, static sounding and chemical analysis obtained from the present Hangzhou Bay coastal plain. The incised valleys were formed during the last glacial maximum and were subsequently filled with fluvial facies during the post-glacial period. All commercial gases are stored in the flood plain sand lenses of the incised valleys.
LIU Guijian , GAO Lianfen , ZHENG Liugen , ZHANG Haoyuan , PENG Zicheng School of Earth , Space Science , University of Science , Technology of China , Hefei , Anhui Key Lab of Loess , Quaternary Geology , Institute of Earth , Environment , Chinese Academy of Sciences , Xi''''an , Shaanxi
2004, 78(3).
Abstract:The Yanzhou mine district, located in southwestern Shandong Province, is about 1300 km2 with more than 8×109tons of proved coal reserves and there are 10 big power plants in this area. A large amount of coal ashes, which are regarded as waste materials, have been stockpiled in the area and have influenced the environment of the mine district. In this paper, analysis of fly ash samples from three power plants is carried out, the enrichment and concentration of trace elements, Pb, Zn, Cu and As, in coal ashes are analyzed, and petrological and mineralogical characteristics and chemical compositions of coal ashes are studied. The aim of this work is to provide basic scientific data for utilization of ashes and reduction of environmental pollutions.
SUN Shenglin , WU Xizun China National Administration of Coal Geology , Beijing , China
2004, 78(3).
Abstract:This paper briefly introduces the development and present situation of China's coal seismic exploration. It focuses on analyzing the important functions of 3-D seismic exploration technology in the designing and production of coal mines, and also the results of its application.
ZHONG Jianhua , WEN Zhifeng , GUO Zeqing , WANG Haiqiao , GAO Jianbo Earth Resource , Information College , University of Petroleum , Dongying , Shandong Guangzhou Institute of Geochemistry , Chinese Academy of Sciences , Guangzhou , Guangdong
2004, 78(3).
Abstract:Typical reefs in the Paleogene and early Neogene strata of the Qaidam Basin, Tibetan Plateau, China, reveal their internal structures and sedimentation environments and consist mainly of algal reef, stromatolite reef and thrombolite reef with distinct reef structures, fore-reef, back-reef and reef-plateau. The fore-reef is characterized by a combination of pinnacle reef, thrombolite and algal reef. The back reef is composed of stromatolite reef and algal reef. The pinnacle reefs (micro-atoll), most of which are several tens of centimeters in diameter (whereas some exceptionally big ones are over 200 cm in diameter), and several tens of centimeter to 2 m in height, are situated on the far front-edge of the reef; the pinnacle reef is also often of recumbent form with a gravel-filled circular hole in the center. The algal reef is in the form of dome and irregular beds, and filled with algal detritus, ostracodes, spirorbis fossils, ooid and terrigenous debris, and worm traces; cavities and scour marks are often developed. The algal reef is gray commonly when fresh and weathers to a brown color. The lacustrine thrombolite in the Qaidam Basin is light gray or deep gray when fresh, white-gray or brown when weathered, dense and homogeneous with abundant pores filled by oil and bitumen. Observed under the microscope, the thrombolite consists mainly of brown or brown-black clots with a little algal debris, ooid, pellet, ostracodes, spirorbis fossils and terrigenous debris, in some cases, terrigenous debris, even gravel, is abundant. Many features of the thrombolite suggest that it is formed in a high-energy envkonment. The stromatolite reefs developed on the lacustrine algal reef in the Qaidam Basin are very complex whether in shape or in internal structure. The simplest ones form laminated layers and the most complex ones have intensely branching structures. The size is also variable.
MEI Mingxiang , YU Bingsong , JIN WeiguangSchool of Earth Sciences , Natural Resources , China University of Geosciences , Beijing
2004, 78(3).
Abstract:The Lower Cretaceous strata in the Kuqa Basin in Xinjiang are marked by a set of arid red beds. Several types of sedimentary fades can be identified in this set of arid red beds: mudstones of the plaza and intracontinental sebkha, aeolian sandstones, sandy conglomerates of the intermittent river, conglomerates of the pluvial fan, etc. These types of sedimentary facies constitute a typical desert system. Therefore, the Cretaceous strata in the Kuqa Basin provide a favorable condition for studies of sequence stratigraphic divisions of the desert system. With the rise and fall of the base level of the sedimentary basin, cyclicity is clearly revealed in stratigraphic records, which helps the identification of the third-order sequences. Based on the cyclicity in stratigraphic records, 5 third-order sequences can be found in the strata of the Early Cretaceous in the Kuqa Basin. These sequences comprise a second-order tectonic sequence. The primary feature of these third-order sequences is of an upward-fining sedimentary succession formed by a succession of "coarse sediments of the alluvial system-fine sediments of the lake system". The result of this study shows that aeolian sandstones are the best reservoirs of natural gas in the Cretaceous strata in the Kuqa Basin, and that the Kela-2 gas field is the first large gas field dominated by aeolian sandstone reservoirs in China.
Chief Editor:HOU Zengqian
Governing Body:China Association for Science and Technology
Organizer:Geological Society of China
start publication :1922
ISSN:ISSN 1000-9515
CN:CN 11-2001/P