1998 Vol. 20, No. 4

Display Method:
A TECTONIC OUTLOOK OF MOBILISM ON BASIN STUDY
Wu Genyao
1998, 20(4): 309-318. doi: 10.11781/sysydz199804309
Abstract:
A short review of history on the oil and gas-bearing basin study reveals the development to experience a zigzag path of structural-sedimentory-tectonic researches.The recent contributions of petroleum geology should be attributed to the plate tectonics.To face a grim situation of oil and gas exploration,we should develop and perfect the tectonic outlook of mobilism,which is a guiding ideology and theoretical instruction on basin study.In the process of basin occurring and sediments depositing,the following changes can be observed in a basin:(1) the basin geometry and framework,(2) the inner textures,(3) the growth structures,(4) the tectonic setting and provenance,(5) the basin type and its formation,and (6) the geothermal pattern.Spatially,the basin analysis of mobilism is expressed by the following relationships:(1) the part and the whole of a basin,(2) a single basin and the basin group,(3) the regional and the local stress fields,and (4) the tectonic styles in the shallow and the deep.In addition,the complexities of continental margins and geothermal fields should be emphasized.A unitedly kinematic process and dynamic mechanics between orogenics and basin evolution can be explored from the viewpoints of (1) compression and tension being interdependent,(2) transformation by strike-slip faults,and (3) deep-seated courses.To comprehend the basin occurring,sedimentation and thermal action,the three efforts should be ma ken greatly:(1) to sum up the features of basin evolution related to the global tectonic cycles,(2) to take tectonics as a key link and to synthesize the knowledges of structural geology,sequence stratigraphy,sedimentology,geochemistry,geothermology,groundwater dynamics and oil-gas accumulation dynamics,and (3) to understand the reformation or influence of the youngest tectono-thermal event.
THE CONCEPT AND PRINCIPLES OF PETROLEUM SYSTEMS DYNAMICS——NEW THINKING AND METHOD OF BASIN MODELING AND PETROLEUM POOL FORMING DYNAMICS MODELING
Wu Chonglong, Wang Xiepei, Mao Xiaoping, He Guangyu, Liu Haibin, Yang Jiaming, Wu Jingfu
1998, 20(4): 319-327. doi: 10.11781/sysydz199804319
Abstract:
The authors advise to border the concept of the petroleum system so that it can apply to the whole petroleum geological unit sequence and become a new geological entity.The petroleum geologist can see the geological entity from the angle of the system-science.It is a combination of a research objective and an abstract model and has a gradational structure as well.The petroleum system is substantially a petroleum pool-forming system.The research methods should be the combination of qualitative and quantitative system method.Considering the non-linearity existing in the petroleum pool-forming process and the current defect commonly existing in the basin modeling and petroleum pool-forming modeling,the authors have tried to recommend the ideas and the methods of system dynamics,introduce the concept of petroleum system dynamics and clarify its basic principles,thus,establish the methods architecture of petroleum system dynamics elementarily.
THE DISCOVERY OF THE LATE TRIASSIC STRATA AND ITS GEOLOGICAL SIGNIFICANCE IN THE SOUTHWESTERN TARIM BASIN
Chen Ronglin
1998, 20(4): 328-331. doi: 10.11781/sysydz199804328
Abstract:
The first discovered Late Triassic strata was introduced in terms of its petrological and biostratigraphic characters in the paper.The upper Triassic was only distributed in Wuqia-Kusilapu fault depression,which was belonged to a different protobasin comparing with the southwestern foreland basin.This is important for analysis of structural evolution and evaluation of hydrocarbon potential in the southwes tern Tarim depression.
A STUDY OF GAS RESERVIORS OF UPPER SHAXIMIAO FORMATION (J2s) AND ITS ORIGIN IN XINCHANG GAS FIELD, WEST SICHUAN
Ye Jun, Zhu Tong, Zhao Zejiang
1998, 20(4): 332-339. doi: 10.11781/sysydz199804332
Abstract:
By means of reservior geochemistry,the tight sandstone reserviors of the Middle Jurassic Shaximiao formation (J2s) in Xinchang gas field,West Sichuan were studied.The chemical mechanism and physical action for formation of internal anisotropy of reserviors were synthetically analysed with the history of tectonic evolution,diagenesis and hydrocarbon migration and accumulation the reservior underwent.Meanwhile,4 types of reserviors were classified according to hydrocarbon producing potential,dynamic character of gas pool and petrologic data,and the most favourable zones for exploration and development were pointed out.
A STUDY OF SEDIMENTARY MICROFACIES OF SHAXIMIAO FORMATION AND FORECASTING OF FAVOURABLE GAS-BEARING ZONE IN ZHONGJIANG AREA, SICHUAN PROVINCE
Xu Binggao, Li Congjun, Zhao Zejiang
1998, 20(4): 340-345. doi: 10.11781/sysydz199804340
Abstract:
Based on a synthetic study of sedimentary facies,logging facies and seismic facies,Shaximiao formation in Zhongjiang area,Sichuan province was considered to be deposited in a fluvial-lacustrine environment.It underwent evolution process of shallw lake,semi-deep lake,sublacustrine fan,delta to meande ring stream environments from early to late periods.The favourable zone for gas accumulation was pointed out according to the characteristics of sedimentary microfacies in different periods and their distribution.
GEOLOGIC MODELING FOR OUTCROP RESERVOIR OF CONTINENTAL BASIN AND THE CONCEPTUAL SYSTEMS
Jiao Yangquan, Li Sitian
1998, 20(4): 346-353. doi: 10.11781/sysydz199804346
Abstract:
The geologic modeling for outcrop reservoirs depends on the clarification of the characteristic heterogeneity of reservoirs,including the depositional heterogeneity,diagenetic heterogeneity,and the heterogeneity of porosity and permeability.The heterogeneity of resevoirs can be studied on three scales (macroscopic scale,mesoscopic scale and microscopic scale).From the study of depositional heterogeneity on different scales,the essential procedure is to model the internal architectural frame,for which it is significant to complement and improve the conceptual order for the internal architectural units and bounding surfaces.This paper indicates the common channel units in various channels,explains the differences of the internal architetural complexity and beddings for different channel sand bodies,and takes the different palaeocurrent energy and depositional modes as the major causes for the differences.Modeling the strong permeation net frame is based on recognition and differentiation of fluid flow units which are building blocks differentiated with isolate barrier beds as the bounding hydrodynamic conditions and are closely related with the internal architectural units of sand bodies in scales and spatial distribution.The study on the heterogeneity of reservoir porosity and permeability of different scales depends on different subjects,for instance,the study for mesoscopic scale is focused on the differences between fluid flow units and the differences between the reservoir lithological facies which formed the architectural units.Deposition significantly dominates the porosity and permeability of reservoirs,but in case of heterogeneous diagenesis in superposition,the integral porosity and permeability will greatly decrease.
EVALUATION ON THE GEOLOGIC CONDITIONS OF THE MESOZOIC HYDROCARBONS IN THE LOWER YANGTZE AREA
Guo Nianfa, Lei Yixin
1998, 20(4): 354-361. doi: 10.11781/sysydz199804354
Abstract(1302) PDF-CN(542)
Abstract:
The Mesozoic group in the Lower Yangtze area possesses the features of both marine and continental basinal deposits,and develops marine and continental hydrocarbon source rock,respectively.The Lower Triassic marine source rock is the most favorable one in the Lower Yangtze area,and the continental deposit has certain hydrocarbon-generating potential.Indosinian-Yanshanian movement greatly reforms proto-marine basins,takes significant effect on the preservation of marine hydrocarbon traps,and meanwhile has important control over continental source rock.However,the prospects for hydrocarbon exploration are still good in the areas with relatively weak tectonic movement,especially in some major Mesozoic basins within the area.
PETROLEUM SYSTEM AND PETROLEUM EXPLORATION TARGETS OF THE JIUXI BASIN
Zhao Yingcheng
1998, 20(4): 362-367. doi: 10.11781/sysydz199804362
Abstract:
In this paper,the geologic background of source rock development and the properties and distributive rules of source rocks in the Jiuxi Basin are dissected,the disposition relation of petroleum generating period to trap-developing period,the direction and pathway of petroleum migration,the characteristics and distribution of reservoir rocks,regional cover rock distribution and pool-forming rules are analyzed,and the basic regularity for the generation,storage,capping,migration,trapping and preservation of petroleum in the basin are summarized.On this base,the main petroleum pool-forming condtions which restrict the Jiuxi Basin are studied,and the favorable exploration domains and targets are pointed out.
OIL-GAS POOL TYPES AND THEIR DISTRIBUTION CHARACTERISTICS OF DONGXIN COMPLEX FAULT-BLOCK OIL & GAS FIELD
Jiang Youlu
1998, 20(4): 368-373. doi: 10.11781/sysydz199804368
Abstract:
The oil-gas pool types and their occurrences in the largest fault block oil and gas field of China,Dongxin oil-gas field,are mainly discussed in the paper.The oil and gas pools can be divided into fault bolck,fault-nose,lithologic,and combining types of fault and lithologic ones,etc.,and fault-block pool is the most important among them.In the fault blocks,the multiple oil and gas pools,usually a few dozens,occurred vertically along fault as a superposition pattern.From the lower hydrocarbon-bearing horizons to the upper ones,oil pools,oil-gas pools and gas pools occur in turn.The distributions of oil and gas in different fault-blocks are uneven,and both flanks of the fault-anticline zone concentrated more oil and gas than other parts of the structure.Faults played an important role during the migration and accumulation of hydrocarbons,and it is the double parts both barriers and passways to fluid migration that formed multiple petroliferous horizons in Dongxin complex fault-block oil-gas field.
A CARBON DIOXIDE GAS FIELD IN HUANGQIAO, NORTH JIANGSU PROVINCE——A SPECIAL POOL-FORMING TYPE
Gong Yujin, Zeng Weixiong
1998, 20(4): 374-378. doi: 10.11781/sysydz199804374
Abstract:
The carbon dioxide gas field in Huangqiao,North Jiangsu Province is one of the largest ones which have been developed and utilized at present in our country.Its geologic reserves is 260×108m3,and its basic explored reserves is 64×108m3.The deep of the field consists of stratified and massive gas pools,and the shallow consists of Helium-rich natural gas pools.The composition and isotopic data of the field indicate that carbon dioxide comes from deep mantle.Gas pools are mainly formed by migration and accumulation through fissures.They have later pool-forming times.
DISCUSSION ON THE PROBLEMS OF COAL-RELATED OIL FIELDS
Hu Sherong, He Lixiang, Zhang Xichen
1998, 20(4): 379-381. doi: 10.11781/sysydz199804379
Abstract:
If the oil fields whose major contributing components are coal rock exist in the coal-bearing system of the world? Coal rock can be classified as humic and sapropelic coal.Based on the investigation to the research history of coal-related oil in the world,it is pointed out that not only sapropelic coal can generate oil but also the oil can form coal-related oil fields.But the oil fields whose major contributing components are undisputedly humic coal have not been discovered so far.
THE INFLUENCE FACTORS AND OCCURRENCE PATTERNS OF COALSEAM METHANE IN SANKUANG MINE
Jiao Xiying
1998, 20(4): 382-384. doi: 10.11781/sysydz199804382
Abstract:
There is coalseam methane in coalbed and coal-bearing sequences in the study area.On basis of study of main influencing factors on accumulation of coalseam methane,an occurrence pattern for coalseam methane was suggested and distribution of methane in the surrounding area was predicted.
HYDROGEOLOGIC FEATURES OF CARBONIFEROUS-PERMIAN COAL BED GAS-ENRICHED AREAS IN NORTH CHINA
Wang Mingming, Lu Xiaoxia, Jin Hui, Lin Jie
1998, 20(4): 385-393. doi: 10.11781/sysydz199804385
Abstract:
The hydrogeologic environment of coal bed gas fields in North China is divided by the authors into six types:contribution,strong alternation,weak alternation,detention,stagnation and drainage zone.It is considered that the hydrogeologic environment of Dacheng area is a weak alternation-detention zone with not obvious confined conditions,that of Jincheng area is an open and weak alternation zone,and that of Liulin area is a detention zone with good confined conditions.By analyzing on the hydrogeologic conditions of coal bed gas-enriched areas in the San Juan Basin and the Black Brave Basin of the United States,it is suggested that the areas nearby contribution zones,the gentle areas with sharp water potential surface,the areas with higher degree of NaHCO3/H2O-type mineralization and the areas with good inherited palaeohydrogeologic conditions are favorable for the enrichment of coal bed gases.The Guanbao River Valley,the northerm part of Sanhuzhuang,the western side of Shilou and the eastern side of Guxian County are elected preliminary as four favorable exploration blocks.
A QUANTITATIVE METHOD OF PREDICTING COAL BED GASES IN SHANXI PROVINCE
Wei Yongpei, Li Xia, Chen Huixin
1998, 20(4): 394-397. doi: 10.11781/sysydz199804394
Abstract:
In this paper,the coal bed gas resources in Shanxi Province are summarized.The principle and calculation process of the Fusi Model-recognition Method are introduced.This method is first used to the quantitative prediction of coal bed methane in Shanxi province.As a result,the plane distributive characteristics of methane-rich,methane-fair and methane-poor areas are pointed out.
STUDY ON THE EXTENSION HISTORY OF THE OKINAWA TROUGH BY A TWO-LAYER EXTENSION MODEL
Jiang Xingge, Zhu Jianhui, Jiang Hongkan
1998, 20(4): 398-404. doi: 10.11781/sysydz199804398
Abstract:
Based on the geologic and geophysical data of the Okinawa Trough,the reflection of two times of extension during the forming of the Okinawa Trough in the thickness of lithosphere,the thickness of Earth's crust,the heat flow value of Earth's surface,tectonic subsidence and thermal subsidence as well as geotemperature field is calculated by a two-layer extension model.Besides,the interrelation among parameters is discussed,and effect of each type of parameters on the calculated results is estimated.These results have provided important clues for understanding the extension history of the Okinawa Trough.
NEW UNDERSTANDING TO THE EVOLUTIONARY CHARACTERISTICS OF NATURAL BITUMEN IN CARBONATE ROCKS
Gao Zhinong, Chen Yuanyin
1998, 20(4): 405-410. doi: 10.11781/sysydz199804405
Abstract:
The reliability of natural bitumen reflectance (ROB) as a maturity index of carbonate strata is always a controversial issue which has not been settled completely.It is revealed in studies that bitumen of different genetic type possesses different optical evolutionary characteristics and rules and has characteristic molecular structural and chemical composition.Therefore,special relational equations between ROB and vitrinite reflectance (RO) must be set up respectively for different bitumen,and the geneses of bitumen be classified according to the characteristic structure and composition of different bitumen types.Besides,the evolutionary characteristics of aromatic fraction and asphaltene in bitumen are studied preliminary by means of Gas Chromatography/ Fourier Transform Infrared Spectroscopy (GC/FTIR) and High-performance Liquid Chromatography (HPLC) There are indeed a wealth of evolutionary information in these compounds.But the studies on them is seriously behindhand.
A NEW INDEX FOR THE MATURITY OF CRUDE OIL AND HYDROCARBON SOURCE ROCK——METHYLDIADAMANTANE INDEX
Zheng Lunju, Cao Jianping, Xue Jianhua, Bie Daozhe
1998, 20(4): 411-416. doi: 10.11781/sysydz199804411
Abstract:
Based on the forming mechanism of diadamantane,the thermal evolution relation among isomers as well as the actual GC-MS detection results of diadamantane-type compounds in the saturated hydrocarbon components of T-J source rock from the Shuanghu area of Tibet,five diadamantane indexes are put forward.By correlation analysis with RO,it is suggested that methyldiadamantane index(MDII) can be applied as a new maturity parameter for source rock.On the basis of thermal modeling experiments with the lignite (RO=0.46%) from Baise,Guangxi,the thermal evolution rules of MDII are discussed.MDII has good positive correlation with RO,and their correlation coefficient is 0.83.As the index for the thermal maturity of organic matter,MDII is applied within the limits of mature and high mature stages.
HYDROCARBON-GENERATING POTIENTIAL OF DIFFERENT MICROMACERALS FROM CAOLS OF LONTAN FORMATION IN MIDDLE-SOUTHERN HUNAN PROVINCE
Chen Chunfang, Zhang Aiyun, Qu Meiyan
1998, 20(4): 417-421. doi: 10.11781/sysydz199804417
Abstract:
Based on research of coal petrology and organic geochemistry,hydrocarbon-generating potiential of different coal micromacerals which separated from gas coal and fat coal of Longtan formation in the middle-southern area of Hunan province has been discussed.The study suggested that exinite was the best maceral for generating hydrocarbon,vitrinite took the second place.Both of them are major hydrocarbon-generating macerals,parameters of Bitumen "A" and ROCK-EVAL supported that they can generate oil and gas.Inerlinite is by no means simply a bad source maceral for generating hydrocarbon,it can also produce some gas and its hydrocarbon-generating potiential is decided by the evolutionary stage of coal and the other macerals associated with it.However,its high porosity may be a good reservoir for hydrocarbon.
THE APPLICATION OF ENTROPY ANALYSIS TECHNIQUE ON SINGLE-WELL FACIES DIVISION
Zhang Xiaoli
1998, 20(4): 422-426. doi: 10.11781/sysydz199804422
Abstract:
Entropy is a non-definability measurement in a random process and it is applied to the role of geology,In this paper,Entropy analysis in Markov chains was applied to analysis the systerm entropy and lithic pre-entropy、 post-entropy in every stratohorizon in Deng 1 to Deng 5 well,and then guessed every stratohorizon probability sedimentray facies.
CORE INSTRUMENT CAT.102 AND ITS APPLICATION IN PETROLEUM DEVELOPMENT
Gong Jipin, Zhang Fenjiu
1998, 20(4): 427-430. doi: 10.11781/sysydz199804427
Abstract:
The principle and performance of core instrument Cat.102 were introduced in the paper.The importance of laboratory tests for evaluating sensitivity of hydrocarbon reserviors was highlighted and the applications of the instrument in oil and gas development were suggested.