石油实验地质

Contents Vol.31,No.5 Oct.,2009

2009, 31(5)

Abstract(907) PDF-CN(702)

Abstract:

DIGITAL BASIN：A NEW STAGE FOR STUDYING THE CHINESE PETROLIFEROUS BASINS

Gao Changlin, He Jiangqi, Huang Zeguang, Liu Guangxiang, Fang Chengming, Pan Wenlei

2009, 31(5): 433-440. doi: 10.11781/sysydz200905433

Abstract(1621) PDF-CN(977)

Abstract:
Based on the analysis of exploration history and basin research history,the study of the Chinese petroliferous basins can be divided into the tectonic stage(1945-) and the basin analysis and basin computer simulation stage(1980-).Digital basin stage was occurred in present(2000-).There are different research domains between digital basin and digital oil fields.The digital basin is comprehensive application of the digitized geological datum by using modern geological theory and digital technological method.The aim of digital basin is provided the technological support for evaluation of petroliferous basins.The most inportant task of the digital basin is the construction of data warehouse.There are 12 databases in the basin evaluation data warehouse.

2009, 31(5): 440-440. doi: 10.11781/sysydz200905440

Abstract(563) PDF-CN(222)

Abstract:

STUDIES OF VOLCANIC RESERVOIR FORMING CHARACTERISTICS OF CHANGLING FAULTED-DEPRESSION, THE SONGLIAO BASIN

Lu Jianlin, Zhang Yuming, Xu Hongjie, Zhao Deli

2009, 31(5): 441-448. doi: 10.11781/sysydz200905441

Abstract(1379) PDF-CN(1378)

Abstract:
The volcanic rock of Yingcheng Formation in the Changling Faulted-Depression of the Songliao Basin is thick with various types and facies.Microscopic characteristics and formation mechanism of volcanic rock reservoirs have been systematically observed.Formation of volcanic rock reservoirs is divided into 2 stages,the initial diagenesis stage and the later diagenesis stage.During the initial diagenesis stage,primary pores are formed.And in the later diagenesis stage,secondary pores are formed.Tectonic effects take place through out both the 2 stages,forming various primary and secondary cracks.Deep hydrothermal flow and hydrocarbon-generating effects have obviously transformed reservoir.Many large-scale tectonic movements are the main reasons that volcanic rocks turn to high quality reservoirs.Substantially developed high quality volcanic reservoirs in deep formation have enormous exploration potential.

THE FORMATION MECHANISMS OF CAVITY AND CHARACTERISTICS OF CEMENTS AND FILLINGS OF SINIAN SYSTEM IN SICHUAN BASIN

Huang Wenming, Liu Shugen, Zhang Changjun, Wang Guozhi, Xu Guosheng, Yong Ziquan, Ma Wenxin

2009, 31(5): 449-454. doi: 10.11781/sysydz200905449

Abstract(1341) PDF-CN(1119)

Abstract:
Primary fenestral pores and secondary pore-fracture-cave system caused by meteoric water karstification,organic acid dissolution,TSR(thermal sulfate reduction),hydrothermal dissolution and tectonic fracturing are well developed in Upper Sinian Dengying formation.On the basis of geochemistry,petrography,detailed examination of the cores and thin sections,the following inclusions have been reached.Three types of cements including dolomite,calcite,and silica are common in Dengying Formation.They can be subdivided into eight subtypes.Several kinds of cements were mainly formed at the early diagenetic stage,such as fibrous or blade cements,columnar,radial,crescent cement and fine crystal dolomitic cement.Medium-coarse crystal dolomitic cement were formed at the late diagenetic stage.Further more,the silica material and calcite cements were formed at the late diagenetic stage in Yanshan tectonic uplifting movement.The growth of cements and fillings was correlated with regional structural position,and it is the most strongest in the slope zone.Upon carefully study,the source of fluids which had caused the deposition of cements and fillings in cavity,were proved to be external fluids,and they have regional characteristics.The characteristics of cements and fillings were closely related to adjacent rock.

CLASSIFICATION AND CHARACTERISTICS OF HYDROCARBON PRIMARY MIGRATION AND TRANSPORT SYSTEM IN CLASTIC ROCKS

Kang Dejiang

2009, 31(5): 455-461. doi: 10.11781/sysydz200905455

Abstract(1457) PDF-CN(937)

Abstract:
Studies of hydrocarbon primary migration and transport system play an important role in secondary migration,even influencing final reservoir scale.According to researches of transport system during secondary migration,from microcosmic angle,based on generation and combination of different transport channels,the primary transport system in clastic rocks has been divided into 3 types: normal,secondary and terminative.The normal transport system is composed of pore throat and kerogen network.Hydrocarbon(most miscible phase and little immiscible phase) is expelled from source rock by capillary driving force formed from hydrocarbon bulging.The secondary transport system is formed by a large quantity of secondary microcracks.High excess pressure in source rocks is the main force for immiscible hydrocarbon expelling.In the secondary transport system,hydrocarbon expelling quantity is the largest and efficiency is the highest.The terminative system is composed of intergranular cracks and residual microcracks.The low excess pressure acts as the main force.The efficiency is low and the translocation is very weak,even down to vanish.Along with changes of burial history of source rocks in basins,the normal and the secondary transport system can transform reciprocally to certain extent,whereas the terminative system means the end of perpetual close of the primary transport canals and the complete finish of transport period.

PERMIAN IGNEOUS ROCK DISTRIBUTION AND ITS INFLUENCE TO THE THERMAL EVOLUTION OF SOURCE ROCK IN SANTANGHU BASIN

Gao Gang, Liang Hao, Shen Xia, Jiao Lixin, Li Huaming

2009, 31(5): 462-465. doi: 10.11781/sysydz200905462

Abstract(1410) PDF-CN(824)

Abstract:
Through the studying of thermal evaluation relationships between igneous rock and source rock,it shows that igneous rock directly affects thermal evaluation of source rock.The main kinds of igneous rock are basalt,andesite,diabase and tuff etc in Permian.The effusive rock such as basalt,andesite and tuff have very little effect on evaluation of organic matter in source rock,and only intrusive rock such as diabase whose temperature can be kept in a long time and influent maturity evaluation of organic matter.The greater the thickness and the extent of diabase,the better effect on source rocks.It is estimated that the influent vertical depth is less than 200 m.If the scope of diabase is clear,it is facilitate to know the thermal evaluation and hydrocarbon-generating capability of source rock.

GEOTHERMAL FIELD AND ITS EFFECT ON SOURCE ROCK IN THE XIHU SAG, THE EAST CHINA SEA BASIN

Tong Zhigang, He Qing, He Shibin, Yang Shuchun, Xiong Binhui, Hao Jianrong

2009, 31(5): 466-471. doi: 10.11781/sysydz200905466

Abstract(1539) PDF-CN(1147)

Abstract:
Extrapolating the geothermal analysis results of wells into the area without well on the corre-lativity between the temperature and the formation depth or the bottom of the lithosphere,this paper made the geothermal model of all the Xihu Sag in the East China Sea Basin,and analyzed its effect on the Pinghu Formation source rock.The result shows that the geothermal gradient in the northern and southern area is high.The maturity of the Pinghu Formation in the northern area is more than the one in the southern area.In despite of the reserves found in the southwest of the Xihu Sag,the explore potential of the northern area must be emphasized.Most of the hydrocarbon expelled from the Pinghu Formation during 30～10 Ma.The fact that the traps are large,but their hydrocarbon filling degree is little in the Xihu Sag,is the result of the absence of the preservation or the insufficient hydrocarbon charge.The study on the duration relationship between the trap formed and the hydrocarbon expelled is the key to find more reserves in the future in the Xihu Sag.

COMPLEX LITHOLOGIC RESERVOIR FORMATION CONDITION AND LAWS IN PUWEI SUB-DEPRESSION, DONGPU SAG, BOHAI BAY BASIN

Mu Xiaoshui, He Feng, Gu Qin, Zhang Dongxia, Wu Lizhi, Fan Jianmin, Wei Xinyuan, Song Ruirong

2009, 31(5): 472-477. doi: 10.11781/sysydz200905472

Abstract(1642) PDF-CN(1051)

Abstract:
Lithologic reservoirs are formed in complicated conditions in the Puwei sub-Depression,the Dongpu Sag,the Bohai Bay Basin.Wide spread mature source rocks are prolific material basis for reservoir formation.Multiple sources,various sedimentary system types and rapid changes of lithology control distribution and development of lithologic traps.Thick salt development and phase changes form good barrier bed and cap rock for hydrocarbon,which are also the main causes to develop lithologic pools with high pressure and charging.Geological factors such as frequently developed alternated unconventional reservoirs and hydrocarbon formation in multi-phases have made it more complicated for lithologic reservoirs formation.In this paper,it has been carefully researched 4 types of lithologic reservoirs developed in the area,including sandstone up-dip pinch-out trap reservoir,structural-lithologic trap reservoir(sandstone pinch-out collocated with fault),up-dip petrophysical property sheltered trap reservoir and lenticular lithologic trap reservoir.After deep studies on main factors responsible for hydrocarbon generating beds,lithologic phase changes,unconventional reservoir development,breaking activity and so on,reservoir formation law has been definite,which will play an important role for further exploration of the Dongpu Sag.

RESEARCH ON SEDIMENTARY FACIES AND RESERVOIR CHARACTERISTICS OF LOWER CRETACEOUS IN EASTERN WUSHI SAG, TARIM BASIN

Ji Lidan, Gu Jiayu, Zhao Liang, Zhang Jing, Jia Jinhua, Jia Jindou

2009, 31(5): 478-484. doi: 10.11781/sysydz200905478

Abstract(1530) PDF-CN(1144)

Abstract:
The Lower Cretaceous mainly develops in eastern Wushi Sag of the Tarim Basin,which is a series of redish brown sandy conglomerate deposit,featuring coarse grain size and poor roundness and poor sorting.Fan delta and lake facies are the dominant types of sedimentary facies of Lower Cretaceous in eastern Wushi Sag.Debris flow deposits are common in fan delta plain subfacies,and submerged distributary channels largely develop in fan delta front.The lake was extensive and shallow,and grew shore-shallow lacustrine muddy banks and sand bars,the later interlayered in the former as thin layers.Fan delta front sand body and shore-shallow sand bar are favorable hydrocarbon accumulating bodies.The reservoir is middle-fine lithic sandstone and features low porosity and low permeability,developing in middle Shushanhe Formation.Dissolved pores between grains and dissolved pores in grains are the main storage and accumulation space.The controlling factors of effective reservoir were analysized: sedimentary process and interstitial material are important,and diagenesis especially corrosion is also decisive.The distribution of favorable sand bodies in 3-D seismic work area was predicted by the research on wave impedance inversion,which would direct the reservoir distribution forecast.

ANALYSIS OF TENSE-SHEARING CHARACTERISTICS OF HUIZHOU PALEOGENE FAULT DEPRESSION IN PEARL RIVER MOUTH BASIN

Yu Shuiming, Shi Hesheng, Mei Lianfu, Shu Yu, Wu Jianyao

2009, 31(5): 485-489. doi: 10.11781/sysydz200905485

Abstract(1486) PDF-CN(877)

Abstract:
Tense-shearing characters of the Huizhou Paleogene Fault Depression in the Pearl River Mouth Basin has been proved by analyses of rift construction,tectonic characteristics and comparing with physical simulation results.Sub-sags,low uplifts and faults are usually en echelon-distributed in the Huizhou Paleogene Fault Depression,which is the typical character of tense-shearing rift.It is mainly formed by oblique intersecting between principal extensional stress and base structural strike.When principal extensional stress is oblique with base structural strike,strike-slipping is produced and tense-shearing characters of fault basin are formed.

ANALYSIS OF OIL-GAS SOURCE AND RESERVOIR-FORMED MODEL IN WELL YONG 1 OF THE JUNGGAR BASIN

Zhu Rifang

2009, 31(5): 490-494. doi: 10.11781/sysydz200905490

Abstract(1296) PDF-CN(849)

Abstract:
Three types of crude oil with different geochemistry characterization occur in the Jurassic formation in Well Yong 1 of the Junggar Basin.Oil-source analysis indicates that the crude oil in Xishanyao Formation derived from the Permian source rocks,the crude oil in the lower Sangonghe Formation derived from the Jurassic source rocks,and the extract of the oil sand in the upper Sangonghe Formation is the mixture from the Jurassic source rocks and the Permian source rocks.The Permian and the Jurassic is the main source rocks in the Changji Depression of the Junggar Basin.The main generation stage of the Lower Permian is from the Late Permian to the Early Jurassic,the Middle Permian is from Late Tria-ssic to the Early Cretaceous period,and the Jurassic is after the Tertiary period.By studying the structure evolution of the Changji Depression,it is showed that degradation oil accumulated in Xishanyao Formation before the uplift at the end of Jurassic,the normal oil accumulated in Xishanyao Formation after the Cretaceous formation deposited,and the oil in Sangonghe Formation from Jurassic source rocks accumulated later.

DEVELOPMENT GEOLOGICAL CHARACTERISTICS OF THE LOWER PERMIAN OVERLAPPING GAS RESERVOIRS IN DANIUDI GAS FIELD

Duan Chunjie, Chen Luyuan, Wu Hanning

2009, 31(5): 495-499. doi: 10.11781/sysydz200905495

Abstract(1386) PDF-CN(907)

Abstract:
The Lower Permian overlapping gas reservoirs in Daniudi Gas Field consist of P₁s¹,P₁s²,P₁x¹,P₁x² and P₁x³.The gas reservoirs are overlapped each other vertically and intersected horizontally.The gas reservoir type is low permeable and dense sandstone lithologic gas reservoir,which has the constant volume and elastic drive.P₁s¹ and P₁s² gas reservoirs are mainly delta plain subfacies distributary channel sand body deposition and P₁x¹,P₁x² and P₁x³ gas reservoirs are mainly fluvial braided channel sand body deposition.The natural gas from P₁x² and P₁x³ gas reservoirs are dry gas and the rest are wet.The Lower Permian overlapping gas reservoirs are large gas reservoirs with lower abundance,mid-deep and medium-low yielding.Adoptting natural depletion development mode,it showed that single-well production of P₁x³ and P₁s¹ gas reservoirs is relatively high with fairly stable production,P₁x² gas reservoir takes second place and the single-well production of P₁x¹ and P₁x² gas reservoirs is relatively low.Multi-layer producing may increase production of single-well and intermission production is favorable for stable yielding and enhancing recovery of gas reservoir.Recognition to the geological characteristics of Lower Permian overlapping gas reservoirs is the basis of making gas field producing programs and developping gas reservoir scientifically,reasionablly and efficiently.

DIVERSITY IN THE THERMAL EVOLUTION AND HYDROCARBON GENERATION OF SOURCE SOCKS IN DIFFERENT SUB-DEPRESSIONS OF RICH OIL DEPRESSION

Jiang Youlu, Zhuo Qingong, Tan Yuming, Lu Xuesong

2009, 31(5): 500-505. doi: 10.11781/sysydz200905500

Abstract(1723) PDF-CN(879)

Abstract:
Every rich oil depression in the Bohai Bay Basin generally consists of several sub-depressions which are commonly independent hydrocarbon-generating centers.Due to the differences in sedimentary-burial history of these sub-depressions,there are obvious differences in thermal evolution and hydrocarbon generation of source rocks between different sub-depressions and their different structural positions.Taking the main source rocks of Paleogene Shahejie Formation in Dongpu Depression and Dongying Depression of the Bohai Bay Basin for example,the article demonstrated a comparative analysis in the thermal history and hydrocarbon generation history of source rock between major sub-depressions in two depressions,and the control effects on the reservoir formation and distribution were illustrated in detail.The result shows that,in rich oil depression which consists of several hydrocarbon generation sub-depressions,the source rock in the most deep buried sub-depression adjacent to fault in steep slop is the best,which is widely distributed with high thermal evolution degree,great hydrocarbon generation potential and rich resources.Because of the distinction of the conditions of source rock and burial-thermal history,the hydrocarbon-generating cha-racteristics of source rock in different members of the same strata series and different structural positions in the same sub-depression show relatively large diversity.There are obvious diversities in hydrocarbon generation of source rock in different rich oil depressions.

SOURCE ROCK AND OIL GEOCHEMISTRY AND CORRELATION IN SHUANGCHENG-TAIPINGCHUAN AREA, THE SONGLIAO BASIN

Wang Jie, Liu Wenhui, Wang Tieguan, Chen Jianfa

2009, 31(5): 506-511. doi: 10.11781/sysydz200905506

Abstract(1338) PDF-CN(917)

Abstract:
Shuangcheng-Taipingchuan is an important petroleum exploration area in the north of Songliao Basin.By synthetically analyzing geochemical characteristics of petroleum and mudstone,it indicates that petroleum belongs to the same population in Fuyu and Yangdachengzi oil layer.The studied petroleum mainly comes from Qing 1 member and partly from Qing 2+3 member mudstone of the Sanzhao Sag and the Chaoyanggou Bench,but not from Nen 1 member mudstone.Moreover,oil of the Sanzhao Sag and the Chaoyanggou Bench mainly comes from their Qing 1 member hydrocarbon source kitchen.Petroleum of the Changchunling Anticline Belt and the Wangfu Sag mainly comes from Qing 1 member hydrocarbon source kitchen in the Wangfu Sag.Qing 1 member hydrocarbon source kitchen of the Sanzhao Sag and the Chaoyanggou Bench also has partial contribution to petroleum in the Changchunling Anticline Belt.

THE EFFECT OF BIODEGRADATION ON THE DISTRIBUTION AND COMPOSITION OF ALKYLNAPHTHALENE SERIES IN BIODEGRADED CRUDE OILS

Yuan Li, Bao Jianping

2009, 31(5): 512-517. doi: 10.11781/sysydz200905512

Abstract(1480) PDF-CN(803)

Abstract:
Alkylnaphthalene series are the important geochemical parameters to indicate the thermal evolution.Fourteen biodegraded oil samples from Lengdong Oilfield of the Liaohe Basin have been analyzed.The distributions and relative compositions of dimethylnaphthalenes(DMNs),trimethylnaphthalenes(TMNs) and tetramethylnaphthalenes(TeMNs) in differently biodegraded oils have been studied.The biodegradation sequence has been set up,that is,the resistant ability for alkylnaphthalene series to biodegradation is DMNs

THERMAL SIMULATING EXPERIMENT OF SOURCE ROCK AND GASSOURCE CORRELATION IN THE KUQA DEPRESSION OF THE TARIM BASIN

Fan Ming, Huan Jiwen, Chen Zhengfu

2009, 31(5): 518-521. doi: 10.11781/sysydz200905518

Abstract(1440) PDF-CN(827)

Abstract:
9 samples from the Kuqa Depression of the Tarim Basin were collected and thermal simulated with a step of 40℃ from 260℃ to 540℃.The components and ethane carbon isotopic compositions of gases generated from simulated samples were analyzed.The drying coefficients(C₁/(C₂+C₃)) were figured out.Using drying coefficient of natural gas from Well Ku-1 as parameter for interpolation method,the possible thermal maturities of source rock as well as temperatures are calculated.According to geological background and the possible maturity range,the study showed that only the gas generated at about 420℃ from sample YM-4 of Jurassic coal formation is consistent with Well Ku-1 both in hydrocarbon components and ethane isotopic composition.That means Jurassic coal formation is the main source rock of natural gas from Well Ku-1.Combined with ethane carbon isotope,component and maturity data,the simulating gas drying coefficient can be used in gas-source correlation.The interpolation method overcomes the influence caused by organic thermal maturity and provides a new way for study of oil-gas-source correlation.

EXPERIMENTAL SIMULATION OF THE VERTICAL MIGRATION OF HYDROCARBONS FROM THE UNDERLYING RESERVOIR

Cheng Tongjin, Wang Guojian, Fan Ming, Ren Chun, Chen Weijun, Zhu Huaiping, Lu Li, Huang Xin

2009, 31(5): 522-527. doi: 10.11781/sysydz200905522

Abstract(1412) PDF-CN(922)

Abstract:
A laboratory simulation of the migration process of the hydrocarbons through the overlying cap rock to the surface of the earth has been carried out by means of the self-developed physical simulation device.The results show that the hydrocarbons in the reservoir can permeate and diffuse due to the pressure difference and the concentration difference between the reservoir and its surrounding strata,which is described as micro-seepage,and the direction of this micro-seepage is mainly vertical.It is this vertical micro-seepage that drives the hydrocarbons from the reservoir to migrate through the cap rock and eventually reach the surface of the earth,and the migrated hydrocarbons can be detected by modern apparatus and equipment in the surface.The results also show that the vertical hydrocarbon micro-seepage is characterized by intermittent and episodic migration.A new theory of "gas phase permeation along fracture driven by pressure" has been proposed as the possible main formation mechanism of the near-surface geochemical anomaly based on these simulation results and the long-observed results.

ANALYSIS AND APPLICATION OF ⁴He ABUNDANCE IN NATURAL GAS

Tao Cheng, Sun Mingliang, Liu Wenhui, Wang Xiaofeng

2009, 31(5): 528-530. doi: 10.11781/sysydz200905528

Abstract(1363) PDF-CN(834)

Abstract:
A rare gas purification and accumulation system is designed and used in analysis of ⁴He abundance in natural gas together with mass spectrograph.Sensitivity of ⁴He is calculated.The system is proved reproductive.Data from natural gas analysis are compared with those from Mat271 mass spectrograph,and deviation is less than 10%.Natural gas from the Puguang and Jiannan gas fields in the Sichuan Basin is analyzed,indicating that,studies of ⁴He abundance in natural gas is significant for age research of natural gas source rocks and accumulation formation.

QUANTITATIVE EVALUATION OF FAULT SEALING MODE AND CAPACITY IN THE SUBEI BASIN

Liu Yurui

2009, 31(5): 531-536. doi: 10.11781/sysydz200905531

Abstract(1695) PDF-CN(1030)

Abstract:
Faults are well developed in the Subei Basin.The formation of oil reservoir is closely related to multi-control actions of fault passage and fault sealing.Oil reservoirs are mainly complex fault block reservoirs.Based on the analysis of oil reservoir and characteristic of fault seal data set,4 types of essential sealing modes are developed in this paper,which include butt joint seal mode of sand and mud layer(type A),mixed seal mode of sandstone and mudstone of layers(type B),time match sealing mode(type C),and principal stress sealing mode(type D).Type B,C,and D are further classified by forming mechanism and controlling factors of sealing.According to the above,4 parameters controlling fault seal and quantitative evaluation system of fault seal are set up,which are widely used in petroleum exploration and exploitation with immediate effect and economic benefit.

VERTICAL STRUCTURES OF UNCONFORMITY AND ITS SIMULATION EXPERIMENT OF HYDROCARBON ACCUMULATION MECHANISM

Wu Kongyou, Li Linlin, Zha Ming

2009, 31(5): 537-541. doi: 10.11781/sysydz200905537

Abstract(1856) PDF-CN(1189)

Abstract:
The unconformity is an incoordinate connection kept in strata as a result of the depositional break.The vertical structures of unconformity can be divided into 3 layers: rocks above the unconformity interface,weathering clay and paleokarst zone.they not only are the pathways for oil and gas migration,but also provide accommodation for oil and gas accumulation.Simulation experiments show that the hydrocarbon migration along the vertical structures of unconformity is not only controlled by petrophysics and slope gradient,but also can breakthrough the weathering clay in the weak links to flow with communication between zones;Stratigraphic overlap hydrocarbon reservoirs on the surface of unconformity are more easily to form than stratigraphic screened hydrocarbon reservoirs under the surface of unconformity.

APPLICATION OF PERFORMANCE MONITORING TECHNIQUE FOR CO₂ DISPLACEMENT IN COMPLEX FAULT BLOCK OILFIELD

Wu Zhiliang, Zhang Yong, Tang Renxuan

2009, 31(5): 542-546. doi: 10.11781/sysydz200905542

Abstract(1516) PDF-CN(1039)

Abstract:
Oil displacement by CO₂ injection is an important measure to enhance tertiary oil recovery,and it is very important to monitor and evaluate reservoir performance pre-and post-oil displacement.However,there is't a series of matured performance monitoring and evaluating techniques for oil displacement by CO₂ injection at home or abroadyet.Pilot tests of CO₂ miscible displacement have been carried out in Et formation reservoir of CS Oilfield in Qingtong Depression of the Subei Basin.Through combination of performance monitoring techniques(such as interwell trace,well test,water and gas injection profile,produced fluid profile,remaining oil saturation,and properties of oil,gas and water) and relevant monitoring techniques,it meets the requirements of low permeability oil reservoir in complex fault block to prepare testing program for CO₂ miscible displacement,optimize and adjust test parameters and evaluate the effects.

2009, 31(5): 547-547. doi: 10.11781/sysydz200905547

Abstract(517) PDF-CN(218)

Abstract:

2009 Vol. 31, No. 5

NewsMore

Abstracting & Indexing

Core Journal Category：

Source Journal for Databases：

International：

Chinese：

LinksMore