2005 Vol. 27, No. 3

Display Method:
KINK STRUCTURE IN THE WEST HUBEI AND EAST CHONGQING
Ding Daogui, Guo Tonglou, Zhai Changbo, LÜ Junxiang
2005, 27(3): 205-210. doi: 10.11781/sysydz200503205
Abstract(1046) PDF-CN(765)
Abstract:
The raised and steep anticline in East Sichuan fold belt including West Hubei and East Chongqing is actually a regional large-scale kink structure formed by multiple strata series under vertically buckling effect.When the Jiangnan-Xuefeng basement decoupling nappe horizontally extruded from SE to NW,the sedimentary cover of Middle-Upper Palaeozoic basin progressively (decreasingly)deformed and resulted in kink structure.The kink structure is characterized by both shear folding and bend folding.It usually occurs in crisp,thin and large viscidity difference strata series with relatively mean lithology.Kink structure in the West Hubei and East Chongqing is divided into 5 types:flexure anticline,kink anticline,box anticline,chervon anticine and parasitic anticline.Kink structure controls natural gas generation and distribution in the East Sichuan.
CHARACTERISTICS OF PROTOTYPE BASIN AND HYDROCARBON POTENTIAL EVALUATION OF THE LATE TRIASSIC IN THE WEST HE’NAN PROVINCE
Zhou Xinke, Xu Huazheng, Hu Zongquan, Wang Chuangang
2005, 27(3): 211-217. doi: 10.11781/sysydz200503211
Abstract:
Thick stratum was deposited in the west part of southern North China and the Ordos area during the Late Triassic,when the stable North China Craton turned into circum-Pacific tectonic tract.The Upper Triassic of Jiyuan-Luoyang area located in the south-east Ordos basin,with sedimentary facies ranging from lakeshore/shallow lake subfacies (Youfangzhuang,Chunshuyao formations)to bythyal lacustrine facies (Tanzhuang formation),and the source rock thickness and quality were not as good as those in the Ordos basin.During the Yanshan and Himalayan epoch,the Qingyang-Yan'an area of Ordos basin was relatively stable,which was an oil-rich zone with good condition of oil formation and preservation,while the Upper Triassic in Jiyuan-Luoyang area was eroded in the tremendous tectonic movement,and the earlier pool was destroyed.
STUDY ON THE PRESERVATION CONDITION OF GAS RESERVOIR IN SUOTHWESTERN EDGE OF SICHUAN BASIN
Cheng Yan, Lu Zhengyuan, Zhao Luzi, Li Qirong
2005, 27(3): 218-221. doi: 10.11781/sysydz200503218
Abstract:
In the southwestern edge area of Sichuan Basin there is an abnormal phenomenon,i.e.the lower strata (Upper Sinian and Lower Permian)produce the formation water with low salinity,but the upper stratum (the Jialingjiang formation of Lower Triassic)produces gas.On the basis of comprehensive studies for the properties of formation liquid and formation pressure of all wells in the area,the author has drawn out the influencing factors of the gas preservation.They are,faults,the reservoir character,and the subaerial meteoric water penetration from the outcrop of reservoir.Under the influence of structure movement,the thick and tight carbonate in the Upper Sinian and the Lower Permian is easy to create fissure zone,through which the subaerial meteoric water could penetrate into the deeper formations from the outcrop.The thin and low-porosity carbonate of the Jialingjiang formation was little influenced by the subaerial meteoric water.It has been advised that Jialingjiang Formation is the main prospecting formation in the southwestern edge area of Sichuan Basin.
NATURAL GAS EXPLORATION POTENTIAL OF SINIAN IN THE MIDDLE OF SICHUAN BASIN
Hu Shouzhi, Wang Tingdong, Fu Xiaowen, Chen Shijia, Luo Yuhong, Tang Jing
2005, 27(3): 222-225. doi: 10.11781/sysydz200503222
Abstract:
Characteristics of natural gas and reservoir bitumen in the area of Anpingdian-Gaoshiti have been studied by means of gas reservoir,and it is concluded that,source of oil and gas is mudstone in the Qiongzhusi group of Cambrian.Combined with history of regional structure and thin-section analysis,it is suggested that,there are 4 periods of oil and gas accumulation.It is also pointed out that,exploration potential of natural gas in the 4th section of Dengying group of Sinian in the Anpingdian-Gaoshiti area is good,and the key of drilling is to find good reservoir and to avoid drilling on the belt of bitumen seal.
THE JURASSIC DELTA DEPOSIT SYSTEM TRACT AND SEDIMENTATION MODEL IN THE WESTERN SICHUAN FORELAND BASIN, CHINA
Hu Xiaoqiang, Chen Hongde, Ji Xiangtian, Zhang Wenlin
2005, 27(3): 226-231. doi: 10.11781/sysydz200503226
Abstract:
The Jurassic is built of continental clastic deposited sediments in the western Sichuan foreland basin.Its deltaic depositional system is branched out into lake fan delta system and lake delta system.The lake fan delta system,which mainly existed in the Upper Jurassic Suining Formation and Lianhuakou Formation,is made up of fan delta plain subfacies,fan delta front subfacies and prodelta subfacies.The lake delta system,which mainly distributed in the Upper Jurassic Penglaizheng Formation and so on,can be divided into two kinds:apical axis delta and brachy-axis delta,and included delta plain subfacies,delta front subfacies and prodelta subfacies.Sedimentation model of the Jurassic in the western Sichuan foreland basin had two kinds,they are alluvial fan-river (alluvial flat)-delta-lake-lake floor fan model and alluvial fan-fan delta-lake-lake floor fan model.
ANALYSIS OF SILURIAN RESERVOIR-FORMATION CONDITION IN TAHE OILFIELD
Ding Yong, Wang Yuncheng, Xu Mingjun
2005, 27(3): 232-237. doi: 10.11781/sysydz200503232
Abstract:
Tahe oilfield is geographically located at Kuche and Luntai county in Xinjiang Uigur Autonomous Region.It is structurally located at the southwestern slope of Akekule salient in Shaya uplift in Tarim basin.Because of the effects that are caused by late Caledonian event,early Hercynian movement,late Hercynian movement and early Yanshan movement,Silurian System,Devonian System,upper Carboniferous,Permian System and middle-upper Jurassic System are absent in the main part of Akekule salient and in a majority of south slope of Akekule salient.In addition,upper-middle Ordovician is denuded to some extent and is absent in part areas.The Silurian System is absent in most part of Tahe oil field.At present,the Silurian System is mainly met at the southwestern part of Tahe oil field and it mainly is Kepingtage group(S1k)and Tataaiertage group(S1t).The analyses of source rocks,reservoir bed,caprock and trap indicate that the Silurian System in Tahe oil field and its surrounding areas mostly belong to stratum-lithology and stratum-structure composite traps which are mostly connected with stratum truncation or overlap pinching out and a few of them are structural trap and lithologic trap.Researches show that the Silurian System possesses the conditions forming oil and gas accumulation.
EXPLORATION POTENTIAL OF IMMATURE OIL IN THE BAYANHUSHU DEPRESSION OF HAILAR BASIN
Wang Yonglin, Zhang Jiguang, Qin Jianzhong
2005, 27(3): 238-244. doi: 10.11781/sysydz200503238
Abstract:
There are two sets of immature to low-mature source rock of the lower members of Nantun and Damoguaihe Formations developed in the Bayanhushu depression.Dark mudstone of the Nantun Formation is the best with effective thickness up to 360 m,while that of the lower member of Damoguaihe Formation is worse with effective thickness up to 172 m and its hydrocarbon-generating capacity is the same as that of the Nantun Formation.Average asphalt "A" content in dark mudstone of the Nantun Formation is 0.279 8%,and its sedimentary facies is saline to semi-saline lacustrine.In biomarker of terpane series,γ-cetane and β-cerotane is higher,and in steroid series rearranged steroid is lower,which marks water being salified.Pr/Ph of saturated hydrocarbon chromatogram is below 1,with pyrolytic IH about 500 mg/g,H/C about 1.3.Type of organic carbon is mainly type Ⅱ1.All reaches immature oil-generating condition.Thermal evolution of source rock is commonly lower,Ro is mostly less than 0.55%,which is just under the late-stage of immature to the early stage of low-mature.However,expulsion capacity of hydrocarbon is relatively lower.Generating capacity of immature oil in the Nantun Formation is generally (1~4.5)×106t/km2,capable of forming middle-small size immature oil field.
STUDY ON THE ACCUMULATION FACTOR OF THE PETROLEUM SYSTEM OF THE LOWER TERTIARY IN THE PUCHENG AREA, DONGPU DEPRESSION
Ren Laiyi, Wang Yunsuo, Xu Huazheng, Zhang Yuti, Dengjun
2005, 27(3): 245-249. doi: 10.11781/sysydz200503245
Abstract:
The accumulation factor of a petroleum system is the ratio between the amount of the oil and gas accumulated (resource)and the hydrocarbon-generating,and it's the key parameter to evaluation for the oil and gas resources.The Pucheng area is a high-in-sag structural geological unit,in which the exploration degree is high,the geological knowledge is known well,the proven degree for the resource is high as well.It has a clear boundary to supply the oil and gas.The character of the oil and gas reservoir,the formation conditions and the hydrocarbon accumulation history are known well.This system can be thought as a independent and integrated oil and gas accumulation unit surrounded by the separated grooves with the similar characteristics of oil and gas migration.The research on this accumulation factor can be effective to the evaluation for each geological factor.In this paper the basin-modeling method is used to calculate the amount of hydrocarbon from the effective source rocks in the biggest source kitchen,then based on the preven reserves,use the oil reservoir order method and the Wong's circle method to calculate the final proven reserves,in turn to calculate reversely the accumulation factors of this system:the value is 12.9%~15.6% for oil and 0.905% for gas.The result is significant to the research on the oil and gas accumulation factors for the exploration area that has similar geology conditions.
ORGANIC PETROLOGY CHARACTERS OF JURASSIC SOURCE ROCKS IN THE NORTHERN MARGIN OF QAIDAM BASIN
Jiao Guihao, Qin Jianzhong, Wang Jing, Wang Dongliang
2005, 27(3): 250-255. doi: 10.11781/sysydz200503250
Abstract:
there are various organic macerals with different modalities,styles,genesises and optical features existing in Jurassic source rocks in the northern margin of Qaidam basin.They have different chemical compositions and constructions,different parent material styles and potential of forming hydrocarbons.The organic macerals in source rocks mainly include vitrinite,inertinite,exinite,sapropel and mineral pitch base.The main oil-generating components are exinite and sapropel,while the plentiful vitrinite (with the exception of clarovitrinite)and inertinite mainly generate gas.Dark-colored mudstone is mainly composed of minerals.Coal is mainly composed of organic macerals.Shale,oil shale and carbargilite are between both of the above.In all source rocks,shale and oil shale have the largest amounts of component with abundant hydrogen and sapropel macerals have absolute predominance.The main oil-forming components in shale and oil shale are bituminite and mineral pitch base,then stratiform alginate.Dark-colored mudstone has relatively less amount of component with abundant hydrogen.The main oil-forming components in it are stratiform alginate,sporinite and keratose,then mineral pitch base and exinite.The main oil-generating components in coal are relatively low content of keratose and sporinite.Rosin and exinite are in the next place.The main oil-forming components in carbargilite are sporinite,keratose and stratiform alginate.
THE FEATURES AND EXPLORATION PROSPECT OF OUTCROP OIL ACCUMULATION IN QAIDAM BASIN
Qin Changwen, Pang Xiongqi
2005, 27(3): 256-259. doi: 10.11781/sysydz200503256
Abstract:
Outcrop oil accumulation is a special accumulation which is located in the wing of an outcrop anticline or in a monocline in the edge of a basin and is controlled by water table.It is a new explorating field.Through analyzing the geological conditions of oil accumulating and the exploration results in Yuqia oilfield in Qaidam basin,some viewpoints are put forward.Yuqia oilfiold in Qaidam basin is in an uncomplete outcrop anticline without trapping in top.The oil accumulation is lifted by underwater.It forms late and has good oil reservoir rocks with porosity over 17%.The oil in Yuqia oilfield is thin and the buried depth of oil accumulation is from 120 to 450 meters.Being of these features,it is considered as an outcrop oil accumulation.Qaidam basin is arid now.The depth of water table is from tens to hundreds meters in outcrop areas.It is abound in petroleum resources.There are many outcrop anticlines in the basin.The prospects for the exploration of outcrop oil accumulation in Qaidam basin is broad.
RESERVOIR-FORMING DYNAMIC SYSTEM AND DISTRIBUTION OF DEEP-SEATED NATURAL GAS IN THE NORTHERN PART OF SONGLIAO BASIN
Jin Xiaohui, Lin Renzi, Ren Yanguang, Feng Zihui, Song Lanbin, Qin Weijun
2005, 27(3): 260-264. doi: 10.11781/sysydz200503260
Abstract:
The reservoir-forming system research is the inevitable product of petroleum geology from static,qualitative to dynamic,quantitative description.Deep natural gas system is divided into 3 reservoir-forming dynamic systems such as normal pressure gas reservoir system of remote source,superpressure gas reservoir system of proximal source and inorganic reservoir-forming system,according to spatial location of source rocks,distribution characteristics of capping bed,reservoir pressures and mechanisms of migration-accumulation of natural gas in the northern part of Songliao Basin.There are K1q1-2-K1d2 assemblage with gas accumulation closed by K1q1-2,K1d2-K1yc assemblage closed by K1d2,K1yc-Jhs1 assemblage closed by itself.Superpressure gas reservoir system of proximal source is a favorable direction for large-scale and medium-sized natural gas reservoirs exploration.
PETROLEUM MULTISTAGE ACCUMULATION AND DISTRIBUTION IN THE EAST OF OFFSHORE LIAOHE RIVER
Zou Bingfang, Zhang Fenglian, Shen Weizhou
2005, 27(3): 265-268. doi: 10.11781/sysydz200503265
Abstract:
Accumulation may be divided into three periods based on inclusion analysis:E3d3-E3d2,the end of E3d and N1g-N2m.Pool-forming is mainly controlled by trap type,fault activity and growth of cap and reservoir,and the pattern of pool-forming is established.There are different pool-forming stages for different structural zones,resulting in the heterogeneity of oil-and-gas distribution both laterally and vertically.The mid-deep formation in Kuitai area and the slope of Yannan area are the major potential region.
PRIMARY STUDY ON THE EFFECTS OF DEEP-SOURCED FLUID’S MOVEMENT ON HYDROCARBON MIGRATION
Liu Guoyong, Zhang Liuping, Jin Zhijun
2005, 27(3): 269-275. doi: 10.11781/sysydz200503269
Abstract:
In recent years,research on deep-sourced fluid has become a hotspot in geology.A lot of evidences about the movements of deep-sourced fluid have been found in many depositional basins.When this fluid comes into existence in basins,it will produce great impacts on geological structures,evolution of rocks,fluid movements and accumulation of oil and gas.As a part of them,the oil and gas migration is not of exception.Researches show that deep-sourced fluid exists in supercritical state in mantle and lower crust of the earth.It can extract and enrich dispersive organic matters in sediments because of its high dissolving and diffusing capacity,and transport them.Then it can promote kerogen to generate hydrocarbon with hydrogen added,thus it can promote source rocks to expel hydrocarbons.In addition,the physical and chemical reactions between deep-sourced fluid and surrounding rocks greatly improve the porosity and permeability of resevoir,which contributes a lot to secondary migration of oil and gas.Besides,deep-sourced fluid can melt the rocks in crust to form igneous rock,and this rock can prevent the oil and gas migration to form reservoir.
DISTRIBUTION CHARACTERS AND HYDROCARBON-GENERATING POTENTIAL OF BITUMEN OF SINIAN-LOWER PALEOZOIC IN SICHUAN BASIN
Zhang Lin, Wei Guoqi, Wu Shixiang, Wang Zecheng, Xiao Xianming, Zhang Peijun, Sheng Juehong
2005, 27(3): 276-280. doi: 10.11781/sysydz200503276
Abstract:
This paper systematically studies the sort,origin,distribution,capability of hydrocarbon-generating,and main gas-generating times of the bitumen of Sinian-Lower Paleozoic in Sichuan basin.Based on the whole rock polished surfaces configuration and optical characteristic,the bitumen is sorted five types.It has two origin kinds,one is original-in the bed bitumen which mostly distributed in the dark mudstone,fine sandy mudstone,the other is secondary-reservoir bitumen which mostly distributed in the carbonate reservoir rock.Bitumen distributed widely in Dengying formation,its content is higher,from depression (where account for 0.41%)to slope (0.93%~1.13%)and to uplift (2.4%~5.41%),which means higher content in Leshang-Longnusi Paleo-uplift.The Bitumen has high content in weathering zone and become less far from the zone.The Bitumen of Dengying formation of Sinian forms in middle Jurassic,its the main gas-generating time is early Cretaceous which is later than koregen.The Bitumen has strong capability of hydrocarbon-generating which can accumulate to middle gas field.
STUDY OF HYDROCARBON MIGRATION IN THE WEST OF NORTH SLOPE IN GAOYOU SAG, THE NORTH JIANGSU BASIN
Wu Xiangyang
2005, 27(3): 281-287. doi: 10.11781/sysydz200503281
Abstract:
The oil and gas maturity,hydrocarbon migration and accumulation in the west of north slope in Gaoyou Sag are discussed according to such geochemical parameters as steroid,terpane,light hydrocarbon and nitrogen compounds in this paper.Researches show that the oil in Matouzhuang area is low-mature to immature,the oil in Chian area is mature.The oils trapped in Wei 5 Block and Wei 8 Block are biodegraded.The petroleum in the two areas come from different oil sources.The parameters of light hydrocarbon migration show that the hydrocarbon in Chian area comes from Shaobo Subsag.The parameters of nitrogen compounds migration indicate that the hydrocarbons in Chian area migrate from east to west and the hydrocarbons in Matouzhang area migrate from south to north.
RUTHENIUM-IONS-CATALYZED OXIDATION OF AN ASPHALTENE OF A BIODGRADED OIL FROM CAOQIAO OIILFIELD, DONGYING DEPRESSION, BOHAIWAN BASIN-THE DISTRIBUTION OF BIOMARKERS AND THE GEOLOGICAL SIGNIFICANCE
Ma Anlai, Zhang Shuichang, Zhang Dajiang, Jin Zhijun, Chen Zhilin
2005, 27(3): 288-292. doi: 10.11781/sysydz200503288
Abstract:
The asphaltene of a biodegraded oil from Caoqiao oilfield,Dongying depression,Bohaiwan Basin has been investigated by ruthenium-ions-catalyzed oxidation technique (RICO).The products of asphaltene RICO included n-alkanoic acids,dialkanoic acids,tricyclic terpernoid acids,hopanoic acids,gammacerane carboxylic acids,pregnanoic acids,sterane carboxylic acids and so on.The biomarkers were bounded on the asphaltene with specific carbon position respectively.The high ratios of gammacerane carboxylic acids to C30 hopanoic carboxylic acids and a complete series of 4-methyl,4,4-dimethyl steranoic acids indicated that the oil is a mixing oil originated from Es4 and Es3 source rock.The low isomerization of the biomarker acids showed that the maturity of the oil is low.Ruthenium-ions-catalyzed oxidation of the asphaltene provided a new pathway for the oil-oil correlation and oil-source correlation of heavily biodegraded oil.
PHYSICAL SIMULATING EXPERIMENT OF NATURAL GAS MIGRATION AND ITS CHARACTERISTICS OF COMPOSITION DIFFERENTIATION AND CARBON ISOTOPE FRACTIONATION
Shi Ji'an, Sun Xiujian, Wang Jinpeng, Wang Qi, Wang Lei
2005, 27(3): 293-298. doi: 10.11781/sysydz200503293
Abstract:
Comparing with petroleum,natural gas is more active,and its accumulation and dissipation are more complex.In this paper,the characteristics of composition differentiation and carbon-isotope fractionation of natural gas in different carrying beds in migration are discussed according to the result of physical simulating experiment,and the influence of different carrying beds characteristics to natural gas is studied.The result of physical simulating experiment shows that chromatographic effect and fractionation of composition will take place when hydrocarbon migrating.The light-hydrocarbon composition in natural gas,such as methane,has relatively high permeability and migrating velocity.Clay minerals have more powerful bounding force to heavy-hydrocarbon composition than to light composition,and the migration velocities of normal paraffin hydrocarbons and isoalkines in different carrying beds are obviously different.The experimental result also shows that migration can cause the fractionation of carbon isotope of natural gas,and methane carbon isotope is comparatively sensitive to migration conditions and processes.
THE APPLICATION OF STRONTIUM ISOTOPES IN DIVISION OF PALEOKARST STAGES IN TAHE OIL FIELD
Zhang Tao, Yun Lu, Wu Xingwei, Ye Desheng
2005, 27(3): 299-303. doi: 10.11781/sysydz200503299
Abstract:
Tahe oilfield is an Ordovician carbonate rock fissure vug oil pool which is mainly related to unconformity.Its reservoir rock is reformed by superimposition of multistages karstification,so it is very important to identify paleo-karstification stages and confirm distribution of different stage of karstfication reservoir for further exploration.Through recent years exploration,it is thought that the ratio of 87Sr/86Sr is an effective indicator distingishing middle Caledonian stage of karstification reservoir from early Hercynian stage of karstification reservoir.Its theory is that strontium isotope composition in the global ocean water at any one time in geologic history is homogeneous,that is,87Sr/86Sr value in ocean water changes timely.Combined with the geological setting that 87Sr/86Sr value in Caledonian stage of karstification reservoir is different from 87Sr/86Sr value in Hercynian stage of karstification reservoir and the experimental data,Pa-leokarstification reservoir stages is identified and predicted,and distribution pattern in Tahe oilfield is discussed in the paper,which provides geological evidence for further petroleum exploration in Tahe oilfield.
REACTION OF COPPER AND THE ORGANIC MATTER DURING THE SOXHLET EXTRACTION
He Jianqiao, Ma Suping, Xia Yanqing
2005, 27(3): 304-306. doi: 10.11781/sysydz200503304
Abstract:
In order to find whether copper joins the organic compounds reaction,some soxhlet extractor experiments are done.The samples are Huangxian lignite,Shenshan lignite in Ordas basin,argillaceous limestone in Tarim baisn and lime mudstone in Qaidam Basin.They are divided into two series:A and B.In A series,copper is added for eliminating sulfur.And there is not copper with B series during extracting.The results show that copper can react with some organic compounds in extracted matter and form organo-metallic compounds.So it will greatly influence the results of sample pretreatment.After B series experiments,saturated hydrocarbon and sulfur are separated from extracted material as one fraction by co-lumn chromatography.Then we add copper into this fraction to eliminate sulfur.This method can reduce the influence of copper on the quantitative analysis of the organic matter.
FAMM TECHNIQUE AND ITS APPLICATION PROGRESS
Li Zhiming, Qin Jianzhong, Liao Zongting, Zhang Meizhen, Cao Yin, Zhang Changjiang, Shi Weijun
2005, 27(3): 307-311. doi: 10.11781/sysydz200503307
Abstract:
The fluorescence alteration of multiple macerals (FAMM)technique is a new method to determine the thermal maturity of source rocks by means of laser Raman microprobe which measures the fluorescence alteration of multiple macerals.It can effectively resolve practical problems such as the widespread occurrence of vitrinite reflectance suppression in thermal maturity assessment of source rocks.The technical advances and the basis of FAMM technique are expounded,the present application progress is introduced and the practical problems of FAMM technique are also pointed out in this paper.The aim of this paper is to urge its application and study in oil and gas exploration and evaluation of oil and gas-bearing basins in China.
RECOGNITION OF GAS-BEARING RESERVOIR WITH UNDERBALANCE DRILLING METHOD
Bao Yunjie, Peng Suping, Wang Yuquan, Chen Daiwei, Wang Shuxue, He Baolin
2005, 27(3): 312-314. doi: 10.11781/sysydz200503312
Abstract:
Underbalance drilling is one of the most effective drilling technologies in natural gas exploration.Good results have been made in the prospecting areas of Dagang Oilfield and Daqing Oilfield,et al.Some forward requirements for the identification and evaluation of geological logging with drilling gas-bearing reservoirs have been carried out by the application of underbalance drilling technology.In this paper,the localization of logging techniques for gas has been analyzed,and the application method of cutting gas analysis technology for recognition gas-bearing reservoirs in natural gas exploration has been discussed on the basis of characteristics of underbalance drilling technology,and some application examples have been shown.