2002 Vol. 24, No. 2

Display Method:
DEVELOPMENTS IN THE FLUID DYNAMICS AND HYDROCARBON MIGRATION OF SEDIMENTARY BASINS
WANG Zhenliang
2002, 24(2): 99-103. doi: 10.11781/sysydz200202099
Abstract:
Fluid dynamics is the nucleus of basin fluid geology.The analysis on the development characteristics and evolutionary history of fluid dynamics is an effective way to study hydrocarbon migration and accumulation at present.Because of the violent deformation of Chinese sedimentary basins in the later stage,hydrocarbon as a fluid mineral,the dynamic feature of its migration,accumulation and occurrence location becomes even more evident.To recognize and evaluate the influence of deformation on basin fluid dynamics will be helpful to the more scientific and effective research of hydrocarbon migration.Based on the comprehensive analysis of function mechanism of the factors affecting basin fluid dynamics,including the burial and diagenesis of sediments,the infiltration of meteorological and surface water,tectogenesis and the relative distribution of underground fluids,the development and difficulties of basin fluid dynamics research at present were expounded,the evolutionary characteristics of basin fluid dynamics were summarized,and some key scientific problems remaining to be solved in the furture research were put forward so as to make further progress in the domain of this research.
STUDY ON THE SEDIMENTARY FACIES AND SEQUENCE STRATIGRAPHY OF THE ORDOVICIAN CARBONATE ROCK IN TAHE OILFIELD
LIU Wen, LI Yonghong, ZHANG Tao, LI Guorong
2002, 24(2): 104-109. doi: 10.11781/sysydz200202104
Abstract:
In accordance with core and thin section observation,the oosparite and algal bindstone of S69-S76 wells on the southern margin of Tahe oilfield is in contrast with the micrite,sparry limerudite or limearenite and microspar limearenite in the other areas.So,the boundary of the Early Ordovician sedimentary framework should be shifted westward to the line along Kunan 2 to Mancan 1 wells.According to lithology,rock texture,sedimentary tectonics,section structire,paleontological assemblages and other marks,open platform,intraplatform shoal and platform-marginal knob-and-beach three types of sedimentary facies were recognized in the Lower Ordovician,and deeper-water shelf and peritidal sedimentary facies were recognized in the Middle-Upper Ordovician.From the angle of sequence stratigraphy,the Lower Ordovician can be divided into transgressive and high-water level system domains two secondary sequences,and the Middle-Upper Ordovician can be divided into transgressive,high-water level and low-water level system domains.Meantime,the development characteristics of sequences and system domains were studied,and the comparison scheme of the Lower Ordovician sequence stratigraphy was determined preliminarily.
ANALYSIS ON THE CENOZOIC PETROLEUM SYSTEM IN THE WAN’AN BASIN, NANSHA AREA
LIU Botu, CHEN Changsheng
2002, 24(2): 110-114. doi: 10.11781/sysydz200202110
Abstract:
The Cenozoic petroleum system in the Wan'an Basin is made of the Oligocene-Middle Miocene source rocks,the Pre-Tertiary bedrock-Miocene reserviors and the Pliocene-Quaternary caprocks.The traps are dominated by fault blocks,anticlines and reefs.The main source rocks reached the peak of hydrocarbon generation and expulsion in the end of the Middle Miocene and presently are in the high-to over-matured stage.Various traps were formed before the end of the Middle Miocene and hydrocarbon accumulation was in its way in the end of the Pliocene.Hydrocarbon migrated both horizontally and vertically in short distance and was caught up by a resistive system.The traps were over-or normal-charged.In a word,the Wan'an Basin is favorable for hydrocarbon exploration as a result of its long hydrocarbon generation,late accumulation and good preservation.
CONTROLLING FACTORS OF HIGH GAS PRODUCTION IN THE UPPER PALEOZOIC OF WUSHENQI GASFIELD, THE SHANGANNING BASIN
ZHANG Ming, DENG Hongwen, CUI Baochen, MU Fuyuan, FAN Xiaofeng
2002, 24(2): 115-118. doi: 10.11781/sysydz200202115
Abstract:
The distribution rules of reservoir fissures and the space-time development characteristics of monosandbodies are focal points for the study of pore-fissure-typed reservoirs,and are also major controlling factors to the high gas production of gas fields in the middle part of the Upper Paleozoic in the Shanganning Basin.It was considered that the development of structural fissures in reservoirs is obviously related to the lithology and thickness of monosandbodies as well as the tectonic location where reservoirs are situated,and fissures are most developed in the coarse-grained reservoirs located at the high part of noses.According to this cognition,the distribution rules of fissure plane were predicted.Based on the establishment of high precision and isochronous stratigraphic framework,the development rules of monosandbodies and the space time changes of accumulation features were studied and the distribution of effective reservoirs was predicted starting with the Sedimentary facies and microfacies of reservoirs.
DEVELOPMENT OF THE NS FAULTS ON THE WESTERN MARGIN OF THE ORDOS BASIN AND ITS GEOLOGIAL SIGNIFICANCE
ZHANG Qinglong, XIE Guoai, REN Wenjun, YUAN Yuzhen, XIAO Wenxia, GUO Lingzhi
2002, 24(2): 119-125. doi: 10.11781/sysydz200202119
Abstract:
The geometrical,kinematical and dynamical characteristics of the Qingtongxia Guguan Fault,a most important fault of the fault zone on the western margin of the Ordos Basin,were studied comprehensively in this paper.It is considered that the diabase outcropped in the fault zone belongs to "tectonic cool emplacement".The two sides of the fault zone have different geological development history of their own before the Carboniferous Permian period,and the sedimentary environment of the two sides is identical on the whole after the Triassic.It is suggested that the fault should be the collision-and-matching zone of different terranes.The Qingtongxia Guyuan fault zone plays an important controlling role in the formation of the Qilian Orogenic Belt on its western side and the Central Paleouplift of the Ordos Basin on its eastern side.
INFLUENCE OF DIAGENETIC MINERAL FACIES BELTS ON THE ACCUMULATION PROPERTIES OF SANDSTONE IN THE WESTERN SICHUAN DEPRESSION
RAO Dan, ZHOU Dongshen, JIA Cunshan
2002, 24(2): 126-129. doi: 10.11781/sysydz200202126
Abstract:
The sandstone reserviors show severe heterogeneity in the Shaximiao Fr.in the central part of the Western Sichuan Depression.The accumulation properties of the reservoirs are mainly controlled by diagenetic mineral facies belts.The development of secondary porosity is indicated by the chlorite-zeolite facies belt and the kaolinite facies belt.And where the plate carbonate and quartz overgrowth diagenetic mineral facies belts are developed,the sandstone is with compact texture.
DISTRIBUTION RULES OF NATURAL GAS IN THE WEIBEI BASIN
WANG Zecheng, LI Xiaoqing, CHENG Youyi, WU Damao
2002, 24(2): 130-135. doi: 10.11781/sysydz200202130
Abstract:
Coal,oil and natural gas are coexisting in the Weibei Basin.According to the component and carbon isotope characteristics of natural gas and combining with organic matter types,thermal evolutionary stages and other data of hydrocarbon source rocks,natural gas was classified into bacteriogenetic gas,bacterial-mature oil-typed gas,low mature coal-oil-typed gas,mature oil-coal-typed gas,coal typed gas and other six genetic types.It is clear that different types of natural gas take WE zonal distribution planarly on the whole,that is,high-mature coal-typed gas,mature oil-coal-typed gas,low mature coal-oil-typed gas and bacteriogenetic gas from north to south in turn.The revealment of distribution rules for various types of natural gas provides an important basis for the exploration and development of natural gas in the area.
POOL-FORMING MECHANISM OF THE XIAKOU FAULTED ZONE IN THE HUIMIN DEPRESSION
FU Jinhua
2002, 24(2): 136-140. doi: 10.11781/sysydz200202136
Abstract:
Based on the analysis of burial history,tectonic evolutionary history and stress-field evolutionary history,the contamination factors of mudstone and the normal stress of sections for different strike segments and different periods in the Xiakou faulted zone were calculated.Combined with the mechanical properties of faults and the relationship between fault moving periods and hydrocarbon migration periods,the fault sealing history of the Xiakou faulted zone was studied,and the pool-forming mechanism of the Xiakou faulted zone was remolded.
STUDY ON THE DISTRIBUTION RULES OF HYDROCARBON IN THE NORTHERN MARGIN OF THE QAIDAM BASIN
XUE Guanghua, YANG Yongtai
2002, 24(2): 141-146. doi: 10.11781/sysydz200202141
Abstract:
Based on the exploration results and geological cognition obtained in the northern margin of the Qaidam Basin,the major controlling factors of hydrocarbon accumulation in this area were discussed in depth and the distribution rules of hydrocarbon were analyzed systematically.This has an important significance for refe rence in the petroleum exploration of this area.It was pointed out that the distribution of hydrocarbon in the northern margin of the Qaidam Basin mainly follows four rules.The distribution of effective surce rocks is the precondition to the discovery of hydrocarbon,the thermal evolutionary degree of source rocks determines the resource types of oil and gas fields,the paleotraps formed by the Early Himalayan movement at the end of the Eocene match well with hydrocarbon-generating history,and the shallow strike faults formed since the third episode of the Himalayan movement have greater katogene to primary oil pools.
GAS-GENERATING CHARACTERISTICS OF COAL ROCK AND ITS MARCERAL IN THERMAL SIMULATION
LIU Quanyou, LIU Wenhui, QIN Shengfei, WANG Wanchun, GAO Bo
2002, 24(2): 147-151. doi: 10.11781/sysydz200202147
Abstract:
The coal rock and its marceral six series of samples were conducted a thermal simulation experiment.The temperature was programmed from 250 to 550℃ with a temperature step of 50℃.The gas products were analyzed systematically.The results show that the gas production rate is increasing with temperature for the coal rock and its marceral,is varied at the same temperature for different simulated material,and is different under various temperature for the same simulated material.It is also revealed that the vitrinite and exinite have stronger gas potential,the gas production of the fusinite and semifusinite is very low,and the bulk coal samples display the synthetic hydrocarbon-generating effects of each marceral.CO2 and N2 make up larger percentage in the gas products mainly within low temperature bands.
HYDROCARBON YIELD AND GEOCHEMIAL PARAMETERS AFFECTED BY HEATING TIME AND ADDED WATER AMOUNT IN THE SIMULATION TEST
QIN Jianzhong, LIU Jingwang, LIU Baoquan, GUO Jianying, JIN Juchang, WANG Donglang, GUO Shuzhi, YU Guoying
2002, 24(2): 152-157. doi: 10.11781/sysydz200202152
Abstract:
The simulation test of source rock under different heating time,added water amount and sample grain size was carried out.The yield of oil and gas in the simulation test of source rock varied obviously with different heating time,added water amount and sample grain size.When extending heating time,the oil yield was obviously decreased,and the gas yield of hydrocarbon was greatly increased.When added water amount was changed from 0% to 20% and to 50%,the gas yield of hydrocarbon,the remained oil,the expulled oil,the total oil yield and the total hydrocarbon yield were all obviously increased.When added water amount was more than 50%,the total oil yield and the total hydrocarbon yield were obviously decreased,but the gas yield of hydrocarbon was increased.From 1-2.5mm to 5-10mm of grain size,the total gas yield and the gas yield of hydrocarbon were obviously increased,and the total oil yield and the total hydrocarbon yield were obviously decreased.The simulation test of source rock under different heating time,added water amount and sample grain size showed that the component of oil,the GC and GC-MS of saturated hydrocarbon,the δ13C of gas and oil,the pyrolysis of kerogen,the H/C and O/C atom ratio of kerogen and other geochemical parameters were affected.
EFFECT AND SIGNIFICANCE OF GEOCHEMICAL EXPLORATION IN OIL AND GAS PROSPECTING
CHENG Jun, ZHAO Kebin, LIU Congxi, SUN Changqin
2002, 24(2): 158-163. doi: 10.11781/sysydz200202158
Abstract:
Based on the vertical micro migration theory of hydrocarbons,the geochemical exploration technology detects trace hydrocarbon components by advanced instruments and devices.Different grades of anomalies all have the character of good reproducibility and high stability.Regional anomalies forecast the petroleum prospects of a basin,zone anomalies point out the favorable zones of hydrocarbon enrichment,local anomalies provide basis for trap evaluation or the arrangement of trap drilling,and mineral distribution anomalies indicate the extension outside-border direction of oil and gas fields.Downhole geochemical exploration can predict hydrocarbon reservoirs while drilling and give oil-testing horizons.All above functions of geochemical exploration were discussed by practical exploration examples.It was considered that confusing prospecting stages,being eager for quick success and instant benefit,ignoring applied basic research and insufficient personnel technical forces which existed in hydrocarbon geochemical exploration at present were questions restricting the development of hydrocarbon geochemical exploration technologies.
AN EXPERIMENT STUDY ON THE ACOUSTIC CHARACTERISTICS OF PORES AND FRACTURES IN ROCK SAMPLES
ZHONG Kai, XU Mingjie, WANG Hong, WANG Yong, ZOU Xinning
2002, 24(2): 164-167. doi: 10.11781/sysydz200202164
Abstract:
To investigate the pores and fractures of rock samples from the reserviors of Changqing gasfield,the P wave ultrasonic data with the samples were measured.Much useful information about the inner structure of the samples can be learned from P waves penetrated them.Based on the synthetic analysis of kinematic (such as wave velocity) and dynamic (such as waveform,spectrum) characteristics,qualitative or semi quantitative information about pores and fractures in samples can be determined.Firstly,the existence of pores and fractures makes wave velocity lower,and it is much more obvious for fractures especially those without being fully filled.Secondly,the waveform of samples with pores and fractures shows certain weak break,low amplitude and acoustic attenuation,but well-filled pores have few infleunce on them.Lastly,the influence of pores and fractures on spetrum can be indicated by different filtration of high,middle and low frequency spectrum.Besides,samples with pores and fractures obviously appear velocity anisotropy.
STUDY AND APPLICATION OF THE COEFFICIENT OF HYDROCARBON ACCUMULATION DETERMINED BY MULTIFACTORS
SONG Guoqi
2002, 24(2): 168-171. doi: 10.11781/sysydz200202168
Abstract:
The coefficient of hydrocarbon accumulation is the key parameter for hydrocarbon resource evaluation.Various references have showed that satisfied technology series have not been created although there have been a number of research methods of hydrocarbon accumulation coefficient.This paper discussed the method of hydrocarbon accumulation coefficient determined by multifactor colligating,which primarily integrated geological research with the Folk-Ward Method and the Method of Exploratory Well Statistics in Grid,and given the application to the 3rd hydrocarbon resource evaluation of the Dongying Sag in the Jiyang Depression.
CALCULATION OF DENUDED STRATA THICKNESS BY FLUID INCLUSION DATA—A CASE STUDY OF THREE DEPRESSIONS IN THE EAST CHINA SEA BASIN
LIU Bin
2002, 24(2): 172-176. doi: 10.11781/sysydz200202172
Abstract:
On the plotted graphs of formation temperature of fluid inclusions vs.burial depth,the point with distinct change of temperature corresponds to the erosion surface of unconformity.So,on the diagram of temperature (or pressure) vs.depth a straight line passing through the data points recording the temperature (or pressure) and the depth below the denudation surface can be constructed by the regression method.This line is then extended upward to the point with the coordinate defining the ancient surface temperature,and the corresponding depth is inferred as the ancient surface.The distance between the denudation surface and the ancient surface is the denuded strata thickness.It is essential that strata thickness is corrected by coefficient of compaction when fluid inclusions are trapped in shallow burial conditions.This method has been applied to calculate the denuded thickness of the Tertiary (E1,E2,E3 and N1) and the Cretaceous (K) strata in the three depressions of the East China Sea Basin.The results show that the burial depth of most Tertiary ( E2,E3) strata has just reached or fully entered the thresholds of main peak maturation periods of oil.In the future,the exploration work should be focused on searching for the favorable structural traps prior to the depositional break.For the strata of K,E1 and N1,however,the thermal evolution history prior to the depositional break is unknown while that after the depositional break is much clear.Therefore,attention should also be paid to the structures after the depositional break.
ADSORPTION EXPERIMENT OF EXTRA-HIGH RANK COAL UNDER THE CONDITION OF EQUILIBRIUM MOISTURE CONTENT
FU Xuehai, QIN Yong, LI Guanzhong, XU Lei, HU Chao
2002, 24(2): 177-180. doi: 10.11781/sysydz200202177
Abstract:
In view of the gaps existing in the adsorptive characteristics research of extra high rank coal whose vitrinite has the maximum reflectance(Ro(max))of more than 4.0%,twelve coal samples(Ro(max)>4.0%)were collected systematically and conducted a high pressure and isothermal adsorption experiment under the condition of equilibrium moisture content,and the relationships between the Longmuir constant of extra high rank coal samples and Ro(max),maceral,specific pore volume or specific surface area were analyzed.It was found that inflection point on the curve of Longmuir volume vs.coal rank is around Ro(max)=4.5%.On the basis of above research,the adsorptive characteristics and mechanism of coal were discussed.
MEASUREMENT OF LASER RAMAN SPECTRA IN ORGANIC FLUID INCLUSIONS
HE Mouchun, Lü Xinbiao, WANG Qunying
2002, 24(2): 181-183. doi: 10.11781/sysydz200202181
Abstract:
As an exclusive available approach of measuring molecular components in single fluid inclusion,laser Raman spectra is widely attended.The requirements of samples,the experimental conditions for Raman spectra and the arithmetic of Raman spectra were discussed.The connotation of laser Raman spectra and the significance of organic fluid inclusions in hydrocarbon exploration were briefly introduced.
DESIGNING THE EARLY-STAGE DEVELOPMENT PROGRAM OF OIL/GAS RESERVIORS WITH THE WEIBULL MODEL
GONG Jiuhe, FENG Wenguang
2002, 24(2): 184-186. doi: 10.11781/sysydz200202184
Abstract:
It is very difficult to design an early-stage development program of an oil/gas field due to unsufficient available data.By the Weibull model,an early-stage development program was designed for predicting various parameters related to the developing process.The typical curves of QmaxtR/No vs.ER were proposed,which was convenient and practical.
STUDY ON THE NUMERICAL SIMULATION OF PRODUCTION MECHANISM FOR THE TRIASSIC RESERVOIRS OF XIDALIYA OILFIELD, THE TARIM BASIN
GUAN Xiaodong, LI Guiqing, YANG Qiulai
2002, 24(2): 187-192. doi: 10.11781/sysydz200202187
Abstract:
According to the characteristics of the high water-content stage in which the development of Xidaliya oil and gas field is,the production mechanism of reservoirs is studied from production rate,vertical permeability,the distance from perforation to gas cap or to bottom water and the sensibility of penetration degree four respects,using reservoir numerical simulation softwares and based on single-well models.This provides theoretical bases for the further potential-tapping and recovery-raising of Xidaliya oil and gas field.