2005 Vol. 27, No. 6

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THE BASEMENT TECTONIC CHARACTERISTICS OF THE PALAEOIC BASIN, CHINA
Gao Changlin, Shan Xianglin, Qin Deyu
2005, 27(6): 551-558. doi: 10.11781/sysydz200506551
Abstract:
The Archaeozoic Era(2 500 Ma) is the stage that the continental nucleus occurrs or the proto-continental segment forms.The proto-continental segments firstly occurred in the North of China and(Tarim.) The Paleoproterozoic(1 800~2 500 Ma) is the stage that the continental segments rapidly accrete.The North china,Tarim,Qaidam and Yangtze continental segments were connected by accretion in the end of Paleoproterozoic Era.The Mesoproterozoic (1 000~1 800 Ma) is the stage that the rifts develope.The continental segments which have been connected by accretion in the end of Mesoproterozoic were re-broken up into the North China,Tarim-Qaidam and Yangtze continental segments.In the end of Jinning stage,the North China,Jiamusi,Tarim-Qaidam,Yangtze,Cathaysia and Dian-Zang continental segments integrated each other,becoming a part of Rodinia Super Continent.Beginning from the Neoproterozoic(<1 000 Ma) to Palaeozoic Era,the Chinese Neoproterozoic-Palaeozoic basins formed under the Palaeo-plate tectonic system.
THE TECTONIC STRESS FEATURE AND BASINING DURING YANSHAN STAGE IN THE NORTHWEST OF CHINA
Ji Rangshou, Qin Deyu
2005, 27(6): 559-564. doi: 10.11781/sysydz200506559
Abstract:
Research on the regional tectonic stress field during the Late Jurassic to the Early Cretaceous and Late Cretaceous to Early Tertiary in the northwest of China shows that the state of stress field to the east of Aerjin Fracture is different from the that to the west of Aerjin Fracture.The principal compressive stress of the regional tectonic stress field is NNE-oriented to the east and near-meridional to the west of Aerjin Fracture during the Late Jurassic to the Early Cretaceous.In Late Cretaceous-Early Tertiary,the regional tectonic stress field to the east of Aerjin Fracture basically carry on the state of previous stress field and the direction of the principal compressive stress to the west of Aerjin Fracture is northwestward.This tectonic stress field feature is consistent with the basin prototype,basin reversal and tectonization forming in the relevant period.
EXPLORATION D IRECTION AND TARGET OF NATURAL GAS IN THE BO HAIWAN BASIN
Liang Shengzheng, Ren Tiekou, Zeng Xianyun, Liang Yonghai, Bai Jianhua, Song Xiaoying
2005, 27(6): 565-569. doi: 10.11781/sysydz200506565
Abstract:
111 gas field have been found in Bohai Bay basin by the end of the twentieth century,Original natural gas reserves have been known to be 2 716.98×108m3,and is divided into petroliferous gas and Coal-derived gas according different origin.Based on the research about coal-derived gas resource potential of four prospect area governed by china petroleum group company, This paper suggests to enlarge the exploration achievements in the remaining basin of Carboniferous-Permian in northeast of Center Hebei;break throught the restriction to gain of the gas reserve in the Linqing/Qiuxian depressions;strategically prepare the three diretions of remaining basin of Carboniferous-Permian in the south of the Huanghua depression,and six targets of buried hill such as Matou,Hancun,Quzhou,Wumaying,Wangguantun.
THE OIL-GAS SOURCES OF THE LATE PERMIAN ORGANIC REEFAL OIL-GAS POOLS IN THE PANLONGDONG, XUANHAN, SICHUAN
Mou Chuanlong, Ma Yongsheng, Yu Qian, Guo Tonglou, Tan Qinyin, Wang Liquan
2005, 27(6): 570-574. doi: 10.11781/sysydz200506570
Abstract:
The present paper propose a newly discovered sponge-reef fossil oil-gas pool in the ChangxingFormationin the Panlongdong,Xuanhan,Sichuan.The organic reefs are developedin the middle and upper parts of the Upper Permian Changxing Formation,with a thickness of about 80 m.The rock typeswithin the Panlongdong organic reefs consist significantly of bafflestone and skeletal li mestone.Theorganic reefs are made fromsponge,hydra and polyzoa et al.The occurrence of abundant asphalt in the organic reefs and the strata above and belowthemhas disclosed the migration of oil and gas.The asphalt often fills into pore spaces,fissures and cracks,as well as into brachiopods and sponges.Macroscopically,three phases may be identified for the filling processes of the asphalt :the one is the filling into organicframeworks,intergranular pores,sponges and other organic coelomata such as brachiopods,asindicatedinthe field sections.In this phase,the asphalt occurs chiefly in the organic reefs and reef caps;the secondphase is the fillinginto paulopost fissures(the diameter of the fissures>2mm).In this phase,the asphaltis widespreadin the organic reefs and their cap rocks(including spararenite and dolostone) and secondarypores.The other is the fillinginto paulopost fissures(the diameter of the fissures<2 mm).Onthe basis ofcomparative analysis of δ13C,saturated hydrocarbon chromatogram and biomarkers,the authors contendthat the oil-gas sources vary probably fromthe source rocks of the Changxing Formation.
THE RESERVOIR CHARACTERISTICS OF YANCHANG GROUP IN FUXIAN REGION, ERDOS BASIN
Xie Zhengwen, Xie Yuan, Wang Jian, Wang Shenglang, Li Chunyu, Li Lingxi, Lü Xiaoli
2005, 27(6): 575-582. doi: 10.11781/sysydz200506575
Abstract:
Fuxian County is an area where the degree of exploration for oil and gas in Yanchang Group in the southeast of Erdos Basin is relatively low.Reservoir is a key problem that limit the petroleum exploration in Yanchang Group in this area.Based on the researches of predecessors,the depositional genesis and distribution of reservoir sands as well as the petrologic characteristics,the pore texture and the physical properties of the main Yanchang Group oil reservoirs were studied by using the data of outcrop,core and logging.The result shows that Yanchang Group in this area is a typical tight reservoir with extra-low porosity and permeability.Chang 2,Chang 6 and Chang 8 are three favourable oil-bearing horizons developing in Yanchang Group in this area.
THE EVOLUTION OF FAULTED-BASIN AND DEVELOPMENT OF HYDROCARBON SOURCE ROCKS IN EOGENE OF THE JINXIAN SAG, THE JIZHONG DEPRESSION
Liang Hongbin, Zhu Guangyou, Zhang Shuichang, Liang Yingbo, Ma Shunping
2005, 27(6): 583-587. doi: 10.11781/sysydz200506583
Abstract:
The mud rocks occurred mainly in Eogene Shahejie-Kongdian Formation of the Jinxian sag,the Bohaiwan Basin.The second member of Kongdian Formation(Ek2) and the first member of Kongdian Formation(Ek1) to the fourth member of Shahejie Formation.(Es4) were the most important hydrocarbon source rocks.During the time of early deposit of Kongdian and Shahejie Formation(Ek3 to Es4),the rift active center transferred from south to north,as a result,the subsidence center transferred to north likewise,which took on ‘seesaw' deposition pattern.In the early stage(Ek2),subsidence center of the area occurred in the south of the Jinxian sag,and moved to the north in later(Ek1 to Es4).Therefore,correlating to both the depositional thickness and mudstone thickness,it was apparently that the southern depression prevailed over the northern part.However,as far as Ek1 to Es4 were concerned,it was conversed.In the northern depression,there was a set of evaporated saline-hypersaline lacustrine formation of halite,sulfate,carbonate and sand-mudstone alternating layer.The evaporite had a thickness over 1,000 m,the gypsolith of which exceeded 400 m.The gypsiferous mudstone,dolomitic mudstone,calcareous mudstone and dark mudstone in the formation were high organic-rich,buried at the depth of 2,500 to 3,500 m,which was the major hydrocarbon source rocks in the north Jizhong oilfields while Ek2 dominated the south area.Oil and source rock correlation demonstrated that oil in the north oilfields was featured in high phytane,high gammacerane and high pregnance sterane abundance that differed from oil generated from southern formation.It was believed Ek1-Es4 source rocks made significant contribution to the hydrocarbon input for the north oilfields when oil in the south oilfields generated from the southern Ek2 source rock(or else the Ek1-Ek4).
FORMATION AND DISTRIBUTION OF BIOGAS RESERVOIR IN THE LULIANG BASIN
Zhang Huai, Zhou Liqing
2005, 27(6): 588-593. doi: 10.11781/sysydz200506588
Abstract:
Biogas reservoir in the Luliang basin is mainly vertically distributed in the 3rd and 4th members of Ciying Formation in the Lower Tertiary,with a depth ranging from 400 to 800 m.The major factors which control biogas reservoir include: 1)The Luliang basin pulled apart and subsided dramatically in the Tertiary and sediments compensated rapidly.Sedimentation rate of the Ciying Formation reached 200 to 500 m/Ma,forming favorable structural setting to biogas reservoir;2)The 3rd and 4th members of Ciying Formation developed humic organic matter of rich herbage,moreover,the 2rd member of Ciying Formation mainly developed humosapropelinite;3)Medium burial depth of the 3rd and 4th members of Ciying Formation in deep depression,and the geothermal temperature of 30~60℃ are favorable to the increase of methane bacteria;4)Nitrate and sulphate were nearly depleted below 400 m,therefore methane bacteria increased dramatically;5)In this depth range,pore volume of mudstone reaches 10~140 μm,which motivated dramatic activity of methane bacteria;6)In this depth range,methane formed rapidly in mudstone to prevent the diffusing of underlying methane reservoir.Distribution of biogas reservoir laterally is controlled by sedimentary facies and structural elements.Favorable sedimentary facies include transition zone between deep depressions of the 3rd and 4th members of Ciying Formation which are major gas producing layer,and all kinds of clastic rocks.Favorable structural elements include deep depression and slope intrazone.The overlapped zone is favorable to biogas reservoir formation:1)The 3rd and 4th members of Ciying Formation have big thickness and medium burial depth.They are in the period of dramatic activity of methane bacteria and have big gas producting ability;2)Seal thichness is big with good sealling condition;3)Fault density is far lower than that of border faulted zone and slope outer zone,which is favorable to the preservation of biogas reservoir;4)Sand-shale ratio is mediate and lithologic and lithologic-structural trap are developed;5)There is a barrier between reservoir and atmospheric water of basin margin forming reducing environment with low sulphate which is favorable to methane bacteria activity.
2005, 27(6): 593-593. doi: 10.11781/sysydz200506593
Abstract:
RECONSIDERATION ON MARINE PETROLEUM EXPLORATION PROSPECTS IN THE MIDDLE HUNAN DEPRESSION
Xu Yangang, Qi Kailing
2005, 27(6): 594-596. doi: 10.11781/sysydz200506594
Abstract:
Compared with other exploration areas in south China,the Middle Hunan depression has fairly superior conditions for petroleum accumulation.1)Evolution degree of hydrocarbon source rocks is relatively lower and the Longtan coal series are still dominated by soft coal.2)Regionally,two sets of coal series,the Ceshui and the Longtan,are distributed continuously with fairly good covering ability.Drilling data has proved that oil and gas shows are very active.3)The Middle Hunan depression was located near(equator) in(Paleozoic) and the storm rocks developed widely is favorable for oil and gas migration and accumulation.4)The Jiangnan Xuefeng Palaeo-lifts formed early support condition for preservation and rebuilding of oil and gas accumulation.Therefore,the Middle Hunan depression has fairly good(exploration) prospects.(According) to present exploration status,exploration targets should be the lower combinations in the(Lianyuan) depression,advancing toward the Jiangnan Xuefeng Palaeo-continent gradually.
SEDIMENTARY FACIES AND TECTONIC EVOLUTION IN THE TONGZIYAN FORMATION OF THE LOWER PERMIAN IN THE SOUTHWEST OF FUJIAN PROVINCE
Zhou Zhenqi
2005, 27(6): 597-600. doi: 10.11781/sysydz200506597
Abstract:
The Permian Tongziyan Formation in the southwest of Fujian Province can be divided into 3 members.There are 3 types of sedimentary facies:Liancheng,Longyan and Tianhushan.This formation is generally composed of coal-bearing clastic rock sediments of marine and continental facies,700-800 m thick,reducing from east,south to west,north.Having experienced tectonic evolution,magmatism and weathering degradation in the Indosinian and Yanshan epochs,part of the sedimentary basin of the Permian Tongziyan Formation is preserved.The Indosinian epoch has the largest influence,and the Yanshan epoch the second.
RELATIONSHIP BETWEEN FAULT SYSTEMAND ABNORMAL PRESSURE DISTRIBUTIONIN CONTINENTAL FAULT BASIN—A CASE STUDY OF THE DONGYING SAG OF JIYANG DEPRESSION OF BOHAI BAY BASIN
Chen Baoning, Bai Quanming, Zhou Xiangcui, Li Bao
2005, 27(6): 601-605. doi: 10.11781/sysydz200506601
Abstract:
Continental fault basinis an important basin type in the east of China,and is significant for oil exploration and production.It is characterized by abnormal fluid pressure extensively formed in deep formation and complex fault system.Study of the mutual action of these two characteristics is helpful for the analysis of oil migration and accumulation.Based on the analysis of fluid pressure and fault characteristics of continental fault basin,a precise model of abnormal pressure distribution in sag is made.It is also discussed in this paper the spatial relationship between fluid pressure and fault system and the influence of fault system on vertical distribution of fluid pressure as well as the sealing characteristics.
THE GENERATING MECHANISM OF METHYLATED NAPHTHALENE SERIES IN CRUDE OILS AND THE APPLICATION OF THEIR MATURITY PARAMETERS
Li Meijun, Wang Tieguan
2005, 27(6): 606-611. doi: 10.11781/sysydz200506606
Abstract:
Naphthalene and methylated naphthalene series in crude oils and sedimentary organic matters are formed through isomerization and disproportionation,which can be interpreted by aromatic electrophilic substitution process.The relative concentrations of various isomers are controlled by "electronic effect" and "steric effect".Geochemical parameters related to methylated naphthalenes can be used to indicate the differences of maturity,biodegradation,and source input between oil and sedimentary organic matters.Oil samples selected from Damintun Depression in Bohai Bay Basin have been analyzed for methylated naphthalene series.The results show that the high waxy oils are more thermally mature than normal oils,even though some saturated hydrocarbon composition such as steranes and terpanes isomeric ratios get to equilibrium end.This conclusion is consistent with the geological background and the basin modeling results in the study area.It is proved that these methylated naphthalene parameters are very useful geochemical indicators.
UNDERPRODUCTIVE OIL FLOW IN THE WELL ZC 10 OF THE ZHOUKOU DEPRESSION IN THE SOUTHERN NORTH CHINA BASIN
Rao Dan, Quan Shujin
2005, 27(6): 612-618. doi: 10.11781/sysydz200506612
Abstract:
Discovery of underproductive oil flow in the Well ZC 10 of Zhoukou depression in the Southern North China basin has brought hope for hydrocarbon exploration success.Direct hydrocarbon/source comparison is conducted with lighter hydrocarbon fingerprint,proving that,this oil flow is of mixed source,primarily the Lower Cretaceous dark mudstone and the Middle and Lower Jurassic coal,dark mudstone and carbargillite.Lighter hydrocarbon comes from the Middle and Lower Jurassic.Accumulation condition is analyzed.
APPLICATION OF NUCLEAR MAGNETIC RESONANCE LOGGING TECHNOLOGY IN PHYSICAL PROPERTY ANALYSIS OF ROCK
Wang Zhizhan, Zhai Shende, Zhou Lifa, Deng Meiyin, Wang Shoujun
2005, 27(6): 619-623. doi: 10.11781/sysydz200506619
Abstract:
Hydrogen atoms in oil and water resonate and produce signal in magnetic field.NMR mud-logging technology uses these characteristics in petrophysic survey and evaluation.Based on such experiments that sample type,size and drlling fluid almost have no influence on measurement results,application research and discussion are carried out from such aspects as porosity,T2 cutoff value,permeability,movable fluid saturation,oil saturation,pore and pore throats distribution,wettability,oil viscosity,etc.Research proves that,the NMR logging technology realizes rapid measurement and evaluation of petrophysics,and has guiding significance and reference value for in-site decision-making and after drilling and testing discussion.
EXPERIMENTAL STUDY ON NMR MEASUREMENT PARAMEERS AND RESERVOIR PROPERTIES
Fan Yiren, Ni Zigao, Deng Shaogui, Zhao Wenjie, Liu Bingkai
2005, 27(6): 624-626. doi: 10.11781/sysydz200506624
Abstract:
Nuclear magnetic resonance(NMR) logging can be directly used to determine the properties of the reservoir fluid.But it is affected by instrument parameters of pre-logging and the characters of the fluid itself.In this paper,the influences of echo spacing(TE),wait time(TW),oil saturation and salinity of formation water on the T2 spectrum shapes and the transformation rules were discussed based on the experiments of cores with different porosities acquired from different oilfields.The experimental results indicate that if the parameter TE is selected illogically,the NMR spectrum will lose some reservoir information and decrease the resolution capability to the short relaxation components.Different TW results in different fluid polarization,and the variation in the oil saturation and formation water salinity have different responses on T2 spectrum shape.Therefore,the influence on T2 spectrum of these factors should be considered in NMR logging data processing and interpretation.
APPLICATION OF THE SUPERCRITICAL FLUID EXTRACTION TECHNIQUE IN GEOCHEMICAL PROSPECTING FOR OIL AND GAS
Deng Ping, Wang Guojian
2005, 27(6): 627-629. doi: 10.11781/sysydz200506627
Abstract:
The densities of supercritical fluids are 100 to 1 000 times as much as the densities of gases.Their viscosities are 10 to 100 times less than that of liquids.And their coefficients of diffusion are 10 to 100 larger than that of liquids.A supercritical fluid is easy to penetrate the media and can achieve selective separation on hydrocarbons.Moreover,supercritical fluid extraction can basically remove the harm of organic solvents to human and environment.Generally,the process of supercritical fluid extraction only take 10 to 60 minutes.An existing oil and gas area in a oil field was selected where research on supercritical fluid extraction was made.The result shows that fidelity of the extracted hydrocarbons is high.The comparison between supercritical fluid extraction and the other indicators in petroleum geochemical exploration is possible.Supercritical fluid extraction can supply oil and gas geochemical exploration with reliable information.
A STUDY AND APPLICATION TO ARITHMETIC OF PRODUCTION ALLOCATION OF MULTILAYER COMMINGLED PRODUCTION
Wang Yuewen, Lu Shuangfang, Fang Wei, Zhang Juhe, Huang Xiuping
2005, 27(6): 630-634. doi: 10.11781/sysydz200506630
Abstract:
Aim at the localization of the technique of gas chromatographic fingerprint,which is difficult of being applied to commingled production of three and more layers oil.The authors study and application an arithmetic of artificial nerve network.It has higher precision,and it is nonlinear and applicable to commingled production of more than three layers.Applying this arithmetic,through the analysis of whole hydrocarbon gas chromatographic fingerprint of crude oil in the laboratory,and pick out some characteristic fingerprint which reflect the character of crude oil in single and commingled layer,Setting up characteristic fingerprint data base,and then analyzing and processing them with ANN arithmetic,finding the rules,then the authors apply the arithmetic to the Lamadian and the Saertu oil field.As a result,even to the problem of more than three layers,the results also have high accuracy,and are close to the MFE test results.The application of the arithmetic offers a economical and applied path to production allocation calculations of multilayer commingled production with the geochemistry means.
PETROLEUM RESERVES CALCULATION IN CARBONATE FORMATIONS METHOD USING RESERVOIR CONTROLLED UNIT COEFFICIENTS
Zhang Dajing, Miao Li, Bai Senshu
2005, 27(6): 635-639. doi: 10.11781/sysydz200506635
Abstract:
Unit coefficient refers to hydrocarbon bearing volume in unit reservoir.In reserves calculation,it is in direct ratio to oil saturation which has a close relationship with hydrocarbon accumulation degree.On this basis,a method used in reserves calculation in carbonate formation with unit coefficient is put forward in this paper.For a certain reservoir,unit coefficient can be defined through comparing petroleum geological surroundings to conditions of the other known reservoirs.Reservoir thickness can be defined according to well condition and regional karst distribution.This method is more advantageous in carbonate formations due to the following points: taking full consideration of hydrocarbon transportation and accumulation;finding the key points controlling oil-and-gas reservoir formation;comparing petroleum geological surroundings with conditions of the known area.In parameters definition,more geological factors can be taken into consideration,and difficulties in reserves calculation with volume method can be avoided,therefore the result of reserves calculation with unit coefficient is more reasonable.
ROTATIONS OF THE GALAXY AND THE EARTH AND THEIR RELATIONSHIP WITH EARTH HYDROCARBONS
Xue Chao, Xue Ling
2005, 27(6): 640-648. doi: 10.11781/sysydz200506640
Abstract:
Based on the mode of thinking of systematology,the new geological theory of rotations of the galaxy and the earth and their relationship with earth hydrocarbons is put forward in this paper.Hydrocarbons of which oil and gas are composed are stemmed from accretion during the Galaxy rotation.The evolution of the asthenosphere resulted in the only large scale potential hydrocarbon sources.Hydrocarbon accumulation is governed by the rotation of the earth.As pathways and reservoir spaces,faults control the hydrocarbon distribution on the earth.With the new achievements of modern geophysics and geochemistry,mechanism of earth hydrocarbon migration and accumulation with relation to the layer differentiation of the earth matter and the plate tectonics is elaborated.