2005 Vol. 27, No. 4

Display Method:
THEORY OF EPISODIC MIGRATION AND ACCUMULATION:EVIDENCE AND EXPLORATION SIGNIFICANCE
Zhao Jingzhou
2005, 27(4): 315-320. doi: 10.11781/sysydz200504315
Abstract:
It is evidenced that episodic migration and accumulation is rapid,efficient and periodic as a kind of reservoir formation,and therefore significant to the formation of mid-large oil and gas fields.Like gradual migration and accumulation of hydrocarbon,episodic migration and accumulation is also found to be quite common type of reservoir formation in petroleum basins.Compared with gradual migration and accumulation,episodic migration and accumulation is particularly important in basins that experienced strong orogenies,fault activity or have abnormal pressures.Unlike gradual migration and accumulation,which is more important in cratonic basins,episodic migration and accumulation is more important in foreland and rift basins.It should be noted that episodic migration and accumulation is not fully controlled by hydrocarbon generation window in time,but mainly by tectonic events (fault activity in particular) and evolution of abnormal pressure as well.Consequently,history of tectonic changes,fault activity and/or abnormal pressure development determine that of episodic migration and accumulation.The theory of episodic migration and accumulation is not only an important supplement to the traditional theory of petroleum geology,but also broads the exploration domain and further defines the exploration orientation of mid-large oil and gas fields.
APPLY POOL-FORMING THRESHOLD THEORY TO EVALUATE PRE-JURASSIC RESOURCE POTENTIAL OF THE TURPAN-HAMI BASIN, NORTHWESTERN CHINA
Zuo Shengjie, Jia Ruizhong, Pang Xiongqi
2005, 27(4): 321-326. doi: 10.11781/sysydz200504321
Abstract:
One of the key tasks of petroleum explorationist is to evaluate resource potential of various petroliferous basins.The Pre-Jurassic Formations in Turpan-Hami basin,located in Xinjiang province in the northwest of China,have been explored for several years,but its quantitative resource potential is still unclear.A new concept for petroleum resource potential assessment that is called hydrocarbon pool-forming threshold has been proposed.It refers to the least hydrocarbon amounts dissipated during the process of pool formation in petroliferous basin.The existence of hydrocarbon pool-forming threshold has been proved by statistical analysis,physical and numerical simulation and geological phenomena.Due to the re-lative magnitude of hydrocarbon generation amount and its potential dissipation amount,different basins have different oil and gas resource potential.Only the basins that had entered the pool-forming threshold have exploration potential.By utilizing the new theory,the oil and gas resources of the Pre-Jurassic formations in Turpan-Hami basin have been calculated to be 3.354×108 tons and 2 652×108 m3 respectively.The proved ratio of oil is only 15%,which indicates the great potential of Turpan-Hami basin for further exploration.
STUDY OF PETROLEUM ACCUMULATION SYSTEM AND PATHWAY SYSTEM
Liang Shuyi, Liu Keqi, Cai Zhongxian
2005, 27(4): 327-332. doi: 10.11781/sysydz200504327
Abstract:
Petroleum accumulation system is a natural subsurface petroliferous system which includes all (essential) elements as source rock,pathway system and trap to accumulate petroleum and their effective (configuration.) The configuration of petroleum accumulation system must have the function of accumulating oil and gas which can be formed by none of the individual essential elements.Petroleum accumulation system can be divided into one source with one body,one source with two bodies,one source with three bodies,two sources with two bodies,two sources with three bodies,and three sources with three bodies according to source rock and the configuration of essential elements.Petroleum accumulation system involves the whole process of petroleum generation,migration and accumulation.The configuration of the essential elements has the function of indicating space-time regularities of distribution of petroleum accumulation system.The theoretical classification of configuration in space of the pathway system has been put forward on the basis of genetic classification method.
ANALYSIS ON THE FORMING REGULARITY OF HYDROCARBON ACCU-MULATION AND EXPLORATION PROSPECTS OF THE MARINE BASINS IN YUNNAN-GUANGXI-GUIZHOU REGION
Zhou Minghui, Ma Jianming, Zheng Bing
2005, 27(4): 333-337. doi: 10.11781/sysydz200504333
Abstract:
In this paper,the regional tectonics,sedi mentation,source-reservoir-overlying formations,pre-servation conditions,hydrocarbon accumulation and resource extent about the marine oil-and gas-bearingbasins in Yunnan-Guangxi-Guizhou Region were discussedin accordance with the petroleumgeologic char-acteristics of the basins.The main conditions of oil and gas pool forming in the basins were summed up,and the drilling effect analysis on the recent three i mportant exploration wells in the basins was made.Then,the direction and focal points of oil and gas exploration as well as the ideas of comprehensive re-search about the marine basins in Yunnan-Guangxi-Guizhou Region for the future were put forward.
THE DEEP PROCESS AND PALEOZOIC PETROLEUM PROSPECT OF THE BASINS BY THE SIDE OF QINLING-DABIE OROGENIC BELT
Fan Xiaolin, Chen Zhechun
2005, 27(4): 338-345. doi: 10.11781/sysydz200504338
Abstract:
The deep geophysical survey information was applied to the description of the deep geologic structures and tectonic features of the lithosphere in East Qinling-Dabie orogenic belt.Researches show that the lithospheric tectonics control the deep processes of different basins related to orogenic belts and the tectono-stratification of lithospheric media and tectono-thermal events are in control of basining.The main characteristics of the relationship between lithosphere structure and petroleum prospect within this area are the lithosphere being laterally blocked and vertically decoupled,the asthenosphere mantle upwelling and thin layer crust,the deep processes with plastic deformation of the lithosphere and continent deeply underthrusting and tectonic decoupled as well as the deep thermal fluids upwelling to control the forming and migrating of the Paleozoic petroleum.
BASIN EVOLUTION STAGES AND OIL AND GAS ENRICHMENT——TAKING THE LOWER TERTIARY BASINS IN THE EASTERN CHINA AS AN EXAMPLE
Liu Bin, Zhou Xiaojin, Wang Guoshou
2005, 27(4): 346-352. doi: 10.11781/sysydz200504346
Abstract:
According to petroleum geology evolution of several typical Tertiary basins in the east of China,the process of basin evolution may be divided into three stages of whole descending,whole ascending and whole adjusting.Basin descending stage is the process of material accumlation and energy storage,which causes hydrocarbon formation.Basin ascending stage is the process of energy release and oil and gas reservoir formation.Basin adjusting stage is the process of energy adjusting and material equalization.Based on the analysis of each depression's characters in the basins during the above different evolution stages,we compared the differences of petroleum geology evolution of the oil-rich depressions in the eastern China,and summarized the main control factors of oil and gas enrichment in depressions in the eastern China.It is considered that oil and gas enrich in the basins with full stratigraphic system,moderate sedimentation and denudation.
STRUCTURE AND PETROLEUM ANALYSIS OF THE TANZHUANG-SHENQIU SAG IN THE SOUTH OF NORTH CHINA BASIN
Zhai Changbo, Huang Zeguang, Lin Liangbiao
2005, 27(4): 353-359. doi: 10.11781/sysydz200504353
Abstract:
Based on regional tectonic background and geophysical information,with basin analysis,it is believed that a series of prototype basin which have experienced strike-slip,depression,fault-down and again depression exist in the Tanzhuang-Shenqiu Sag after the Late Jurassic.And this basin mode evolution is consistent with geotectonic background.Structure and subsequent deformation are valuable for pool exploration.The orogenic zone of Qinling-Dabie and fault zone of Tanlu control the evolution of southern North China Basin.
SEQUENCE CONTROL ON TYPE AND ARCHITECTURE OF RESERVOIR BODY IN RIFT-SUBSIDENCE LAKE BASIN
Lai Shenghua, Ma Jianming, Sun Laixi
2005, 27(4): 360-364. doi: 10.11781/sysydz200504360
Abstract:
Sequence development and evolution are determined by relative lake level(accommodation) change and sediment delivery in rift-subsidence lake basin.When relative lake level rises,wave energy increases,lake water prograds toward source area,lake-transgression beach and bar and slumped turbidite increases and lake-transgression fan-delta is formed.When relative lake level dropps,wave energy decreases,fluvial energy increases,lake-regression fan-delta ias formed,sandstone and conglomerate of distributary river course develop,and beach and bar of HST and flood turbidite are formed.Because that hydrodynamic force energy of sedimentary environment in different stages of sequence evolution is different,distribution of sandstone and conglomerate is different.
THE INFLUENTIAL FACTORS AND CHARACTRISTICSOF TRIASSIC YANCHANG FORMATION RESERVIORIN LONGDONG AREA, ORDOS BASIN
Li Fengjie, Wang Duoyun, Xu Xuhui
2005, 27(4): 365-370. doi: 10.11781/sysydz200504365
Abstract:
Chang 3,Chang 6,Chang 7 and Chang 8 Triassic Yanchang formations are the main producing oil layers in Longdong area,Ordos basin.The reservoir-rock types in these formations are arkose,lithic arkose and litharenite with delta and lacustrine facies.Their compositional maturity is low and textural maturity is medium.The clastic rocks experienced compaction,cementation and dissolution,thus producing intergranular pores and secondary solution pores.In profile,the physical properties of Chang 3 reservoirs are the best and in plane,the physical properties of reservoirs in the northeast are obviously better than that in the southwest.Favorable reservoirs mostly occur in the sand bodies in delta-front underwater distributary river channel and river mouth bars.All the composition of clasts,grade scale,content of interstitial materials and diagensis have important effects on the reservoir properties.Six vertical distributional models of reservoir are identified in Yanchang formation in Longdong area.The ascend and descend of base-level cycle with high frequency are main factors which control the distribution of reservoir physical properties.
SEDIMENTARY FACIES EVOLUTION AND FAVORABLE SANDSTONE BODY PROSPECTION IN THE THIRD TO FIRST MEMBERS OF THE SHAHEJIE FORMATION OF PALEOGENE IN THE CHEZHEN SAG OF THE BOHAIWAN BASIN
Wang Jiao, Jiang Zaixing, Chen Shiyue, Jiang Benyong, Xing Huanqing, Du Linxiang
2005, 27(4): 371-377. doi: 10.11781/sysydz200504371
Abstract:
With comprehensive study of outcrop,drilling,ancient life,well logging and seismic data,the Paleogene Es~3-Es~1 strata of study area are divided into 2 secondary and 4 third class sequences,and dividing system tract further.For each system tract period,inshore submerged fan,fan delta,delta,sublacustrine fan and lake facies are generated respectively.Favorable sandstone body is predicted.10 favorable districts which can be classified into 4 types are put forward.All these provide technical supports for subtle reservoir exploration.
CHARACTERISTICS OF CARBONATE RESERVOIR IN THE QUM TROOP OF TERTIARY FROM KASHAN AREA, THE IRAN BASIN
Yu Junfeng, Xia Bin, Wang Shihu, Li Zheng, Xiong Ting
2005, 27(4): 378-382. doi: 10.11781/sysydz200504378
Abstract:
The Tertiary stratum of Iran basin has thickly and broadly deposited great carbonate sediments.A study of carbonate reservoir of the Qum troop in Kashan area indicates that,reservoir distribution has a characteristic of thicker sediments in the south and east.The important reservoir mainly consists of micrite-sparite biological clastic limestone.In addition,primary and secondary pores are both developed in re-servoir space.Primary pore includes biological antrum pore,residual intergranular pore and intercrystalline pore,and secondary pore includes mould pore,intergranular solution pore and intercrystalline solution pore.Porosity is high with predominant penetrability.Lithogenesis is dominantly controlled by cementation and dissolution,and at the same time,tectonic fractures are apparent.Under microscope,oil and gas migration can be checked out easily,which proves that,the Qum troop carbonate rock of Tertiary in Ka-shan area is predominant natural reservoir.
ORIGIN OF HYDROCARBONS IN OIL SAND IN THE SOUTH SLOPE OF NIUZHUANG SAG, THE BOHAIWAN BASIN, EAST CHINA
Li Sumei, Pang Xiongqi, Ma Xiaochang
2005, 27(4): 383-389. doi: 10.11781/sysydz200504383
Abstract:
Correlation of the hydrocarbons in the oil sand and the adjacent Es4 shale extracts from the south slope of Niuzhuang Sag,Bohai Bay Basin shows obvious differences between the oil sand with buried depth less than 2 700 m and the immediately adjacent Es4 shales which was originally considered as the main oil source rocks in the south slope,suggesting the hydrocarbons in shallow oil sand samples are hydrocarbons migrating from the deep seated source rocks.Hydrocarbons in the oil sand samples have normal GC fingerprints,while the adjacent shale extracts with buried depth less than 2 700 m are characteristic of high odd-even predominance of normal alkane,and a distinct bulge composed of undistinguished compounds of steroids and terpanoids was observed in the behind section of the GC fingerprint with high retain time.The low-matured Es4 shales with buried depth less than 2700m also have distinct features including low concentration of geological stereochemical configuration(i.e.20R20S and ααααββ) and such the high content of compounds with low thermal stability as 5-β steranes,13α(H)14α (H)-tricycle terpanes.In addition,little amount of dinosteranes were discovered in all of the oil sand samples while dinosteranes are the main constitution in Es4 shale above normal oil window,further indicating no possibility of the algae-rich Es4 interval with buried depth less than 2 700 m to be the source rocks of the oils in the area.With the buried depth decreasing,the maturity of hydrocarbons in oil sand samples and the level of C35-/C34-hopane increased and the concentration of Gamacerance decreased.These can not only indicate the direction of oil migration,but also reveal the different chemical compositions of hydrocarbons generated by the source rocks with different thermal stages and/or mixing of immature oils or bitumen with normal oils.
STUDY ON THE POOL-FORMING PERIODS OF OIL AND GASIN QIJIA-GULONG SAG IN SONGLIAO BASIN
Hou Qijun, Feng Zihui, Zou Yuliang
2005, 27(4): 390-394. doi: 10.11781/sysydz200504390
Abstract:
There are a series of oil-and gas-bearing reservoirs in Qijia-Gulong Sag in Songliao Basin,including Fuyu,Gaotaizi,Putaohua,Heidimiao,etc.The characteristics of these reservoirs were discussed according to the homogenization temperatures of reservoir inclusions and micro-Fourier transform infrared spectroscopic analysis combining thermal evolution histories of the reservoirs.The types and characteristics of the organic inclusions indicate that there are 3 main migration periods of oil and gas generated from K1q1 source rock.There are different pool-forming periods for different reservoirs,and the oil/gas properties of reservoirs are the comprehensive reflection of multi-period pool-forming processes.The homogenization temperatures of inclusions show that the 3 pool-forming periods of the oil and gas in the sag are in the ends of K1n,K and E respectively.The pool-forming periods are well consistent with the tectonic-developing history in the basin.
MARINE GAS HYDRATE RELATED TO VOLCANO-HYDROTHERMALISM
Zhao Hongwei, Gong Jianming, Chen Jianwen, Li Rongzhu
2005, 27(4): 395-398. doi: 10.11781/sysydz200504395
Abstract:
Hydrocarbonin gas hydrate mainlyincludes biogenic and thermogenic gases.However,within-creasing understandings of gas hydrate,newevidences are coming to light that there exists inorganic gashydrate related with volcano-hydrothermalism,whichis discoveredin ocean floor,subduction zone or ex-tensional valley.Fieldinvestigations and laboratory si mulation have manifested that,seabed serpentiniza-tion could generate inorganic gases.In fact,we have found gas hydrate related with volcano-hydrother-malism whose sedi ments have thin thickness and low organic carbon quantity.Therefore,inorganic gashydrae deposits should be paid attention toin the future.
FORMING OF GAS POOLS IN THE CHENJIAZHUANG SALIENT, THE BOHAIWAN BASIN
Li Min, Zhao Yong, Yang Zhiwei
2005, 27(4): 399-403. doi: 10.11781/sysydz200504399
Abstract:
The Chenjiazhuang salient is located between Zhanhua sag and Dongying sag.Oil and gas exploration there started in the 1960s.Up to now,a lot of natual gas accumulations are found.The natual gas in this area has two sources.They are from the Bonan depression and the Lijin depression.The deep natual gas migrates upward along faults,forming palaeo-generated-newly-stored type of gas accumulation.The reservoir is mainly composed of the braided channel sedimentary sand in Guantao formation and meandering river sedimentary sand in Minghuazhen formation.Moreover,the capping beds over Guantao formation and Minghuazhen formation have developed.The conditions forming gas accumulation are excellent.The plane distribution of the shallow gas in this area is mainly controlled by structural setting and sedimentary facies.The longitudinal distribution of the gas is mainly controlled by the ratio of sandstone to mudstone in formations.Exploration of natual gas in Chenjiazhuang area has a widely promising future.
SEAL MECHANISMS OF DIFFERENT TRANSPORTING PASS WAYS OF FAULT AND THEIR RESEARCH METHODS
Fu Guang, Liu Hongxia, Duan Haifeng
2005, 27(4): 404-408. doi: 10.11781/sysydz200504404
Abstract:
Based on the study of types and characteristics of transporting passways in faults,two types ofvertical seal mechanisms of faults were divided.A vertical seal mechanism of fault is tight and heal sealmechanismfor tip fractures or connected pores of fault zone filled mainly with mustone.Another verticalseal mechanismof fault is diagenetic cementation seal mechanismfor vertical fractures or connected poresof fault zone filled mainly with sandstone.A method studying the tight and heal seal mechanism of faultwas established by using the relationship between surround pressure on fault and plastic deformationli mitof mudstone.Another method studyingthe diagenetic cementation seal mechanismof fault was establishedby using whether deposition of silica and carbonate or not.These method were appliedin studyingthe ver-tical seal mechanismof main fault in the first member of Damoguaihe Formation,the north of WuerxunDepressionin the Hailar Basin.The research results are accordant with actual geological conditions.It in-dicates that the methods are practical to study the seal of different transporting passways of fault.
APPLICATION OF ORGANIC INCLUSIONS TECHNOLOGY TO THE STUDY OF OIL-GAS MIGRATION AND ACCUMULATION
Hou Jianguo, Ren Lihua, Dong Chunmei
2005, 27(4): 409-413. doi: 10.11781/sysydz200504409
Abstract:
In this paper an advanced organic inclusion analysis technique was used to study the homogenization temperature and organic components of hydrocarbon inclusion in E2f of the northern slope of Gaoyou depression.The results indicate that the source inputs mainly come from lower aquatic algae and higher plants waxiness.The sedimentary environment was reducing and the salinity of the water medium was high.The hydrocarbons had been mature before they entered into the reservoirs.Contrasting with biomarker parameters of hydrocarbon inclusions and source rocks,it can be found that the hydrocarbons of the E2f mainly come from the E2f2.Application of organic inclusions to oil-gas migration and accumulation shows that hydrocarbons migration of the study area mainly occur from later Eocene of early Tertiary to late Tertiary and the former one is most significant.It is consistent with regional structural movement in Gaoyou depression.
STUDY ON PHYSICAL SIMULATION EXPERIMENT FOR THE CONTROLLING OF FAULTS TO OIL—TAKING THE HONGCHE FAULTS IN THE NORTHWEST OF JUNGGAR BASIN AS AN EXAMPLE
Shang Erjie, Jin Zhijun, Ding Wenlong, Zhang Yijie, Zeng Jianhui, Wang Hongyu
2005, 27(4): 414-418. doi: 10.11781/sysydz200504414
Abstract:
This thesis researched the mode of the controlling of faults to oil migration and accumulation in the northwest of Junggar Basin,and then defined it to experimental model.when the oil is injected conti-nued and steady into the model,we simulated the process of the oil migration and accumulation in the faults and the reservoir.By observing the process of experiment and analysising the result and studying the character of tectonic stress field and the proof of fluid geochemistry for the controlling of faults to oil,this paper analyzed the character for the controlling of reverse faults to the oil in this area clearly.
SOURCE ROCKS HEAT-PRESS SIMULATION EXPERIMENT AND ITS INFLUENCE WITH PRESSURE IN THE MEMBER 3 OF THE SHAHEJIE FORMATION, MIDDLE-NORTH AREA OF HUANGHUA DEPRESSION
Li Yanjun, Chen Yicai, Zhang Yanyun, Liao Qianjin, Sun Xiaoming
2005, 27(4): 419-424. doi: 10.11781/sysydz200504419
Abstract:
The heat-press simulation experiment is the most direct method for studying the ability of hydrocarbon-generating in source rock.This paper selects by examinations respectively three rock samples in the Member 3 of the Shahejie Formation of Banqiao,Qikou and Beitang Depression to do the heat-press simulation experiments,analyzing with contrasted to the hydrocarbon outcomes,the oil-gas production rate and its phase characteristic.The result shows that three source rocks are all the highly ability of hydrocarbon-generating,the biggest hydrocarbon-generating rate can amount to 300~350kg/t.The source rock in deep of Banqiao Depression mainly produces condensation oil-gas during mature-high mature stage,while the source rock in deep of Qikou and Beitang Depression pruduces oil during mature stage,and produces condensation oil-gas during high mature stage.On the experiment,by changing the experiment pressure to study its influence on hydrocarbon-generating rate and outcome constitution and hydrocarbon-generating phase.In the end,the author clarified that superpressure changes the traditional hydrocarbon-generating mode,enlarging depth and scope of existing oil phase,and extending frontier areas to look for oil.