1996 Vol. 18, No. 3

Display Method:
ANALOGOUS ANALYSIS OF BURIED HILL TRAPS IN THE TARIM AND THE BOHAI BAY BASINS
Gou Huawei, Dong Xiufang, Tian shuyun
1996, 18(3): 229-236. doi: 10.11781/sysydz199603229
Abstract:
The buried hills and buried hill traps in the Tarim and the Bobal Bay basins were compared.Basing on results of case studies of buried hill traps of both basins,the traps wereclassified into U-and UT-type ones. Different kinds of traps showed different characteristics and controlled distribution of hydrocarbon. The buried hills occurred in any kinds ofbasins and composed favourable traps for hydrocarbon accumulation. Therefore,the buriedhill traps in both basins could be the targets for oil and gas exploration.
STRUCTURAL CHARACTERISTICS AND OIL/GASEXPLORATION TARGETS OF DABANCHENGSUB-DEPRESSION OF THE JUGGAR BASIN
Yu Renlian, Yang Shusheng, Zhao Liqun
1996, 18(3): 237-243. doi: 10.11781/sysydz199603237
Abstract:
Dabancheng Sub-depression is a secondary structural unit of Chaiwobao depressionof the Juggar basin. Due to influence of the Yanshanian movement, the area wasseverely faulted and six structural belts were formed. Local block anticlines,controlled bythrust faults, were finally in their fixed forms during the Himalayan movement.There is petroleum geological condition for formation of middle and small oil and gasfields in Dabancheng sub-depression according to the evolution of source rocks and its relationship with formation time of local structure and faults. Chaiwobao fold zone was themost favorable hydrocarbon-bearing structural zone, and Xigeda-Shanshuidi and TudunziXigouxiasi fold zones were potential ones. Meanwhile, the regional Upper Triassic andLower and Middle Jurassic seals were developed on the structural zones, thereby a circularhydrocarbon-rich belt was formed around the center of the subdepression.
THE CENOZOIC STRUCTURAL EVOLUTION AND ITS RELATIONSHIP WITH OIL AND GAS ACCUMULATIONIN THE SOUTHWESTERN TARIM DEPRESSION
Hu Wangshui, Liu XueFeng, Chen Yusui, Xiao Ancheng, Liu Shengguo
1996, 18(3): 244-251. doi: 10.11781/sysydz199603244
Abstract:
The southwestern Tarim depression is a compound foreland depression with a longstructural history during the Cenozoic.It has undergone a relatively tranquil phase of theEarly Tertiary,the important Miocene development phase of structures, the relatively quiet phase of the Pliocence and the formation phase of structures of the Quaternary. Thestructural deformation is characterized by the development of fold-thrust belts and a rapidtectonic subsidence,which has resulted from the collision between the india plate and theEurasian plate and from long lasting compression and pushing. The deformation of thestructures is weakened from backland to foreland. The subsidence of the depression has resulted from structural and sedimentary loading. The Himalayan tectonic movement has enhanced the thermal evolution of the source rocks and formed lots of fault-related folds,which provided good conditions for oil and gas migration and accumulation.
PLATE STRUCTURAL SETTING OF THETRIASSIC-JURASSIC PROVENANCE AND ITSRELATIONSHIP WITH SEDIMENTARY BASIN TYPEIN THE NORTH OF THE TARIM BASIN
Zhang Ximing, Liu Qingfang, Wang Guiquan
1996, 18(3): 252-258. doi: 10.11781/sysydz199603252
Abstract:
In the light of systematic study of a large number of sandstone thin-sections from surface exposure and wells, the authors considered that the Kuqa depression in the north ofthe Tarim basin was a foreland basin,and the Awat-Mannaer depression was an intra cratonic downwarped basin. On the basis of analysis of basinal types,combining the result ofoil/gas exploration in the area,the distribution pattern of hydrocarbon accumulation andhydrocarbon exploration prospect were analysed and predicted.
THE DISTRIBUTION OF OIL AND GAS FIELDS IN JIYANG DEPRESSION OF THE BOHAI BAY BASIN IN VIEWPOINT OF WAVE-LIKE MOVEMENT
Lü Xiuxiang, Zhang Yiwe, Li Desheng
1996, 18(3): 259-266. doi: 10.11781/sysydz199603259
Abstract:
Characteristics of depositional and tectonic activities in Jiyang depression and dustpanshaped structures which were faulted on the northern margin and overlapped on the southern flank showed that mantle plume was migrated in wave-like from south to north. Thatwas verified by tectonophysic modedelling experiment. The migration of mantle plume inwave-like led to the wave-like movement of crust, as a result, Jiyang depression of the Bohai bay basin was formed. Wave-like movement controlled the occurrence of sags and theirarchitectures,the orderly shifting of depositional and tectonic subsidence centers, and theareal distribution of oil accumulations.
THE LUZHOU PALEOHIGH ANDOIL/GAS ACCUMULATION IN SOUTHERN SICHUAN
An Zuoxiang
1996, 18(3): 267-273. doi: 10.11781/sysydz199603267
Abstract:
The Luzhou Paleohigh of the Sichuan basin was formed during the Indosinian movement.It controlled gas accumulation in the Permain Yangxin limestones and the TriassicJialingjiang limestones. With regard to present hydrocarbon distribution of the two sequences,they might undergo two times of migration and accumulation. In addition,composition,origin and dry factor of gas also revealed the same result. Structural pattern of upliftand depression in the Luzhou Paleohigh was changed during the Yanshanian-Himalayanmovement. As a result of this, the hydrocarbon in the Permian and the Triassic was inversed,remigrated and re-accumulated, and gas in the Ordovician had the same experience.It was expected that hydrocarbon was accumulated in the margins of the paleohigh.
THEORETICAL SIMULATION OF EXTENSIONAL BASIN──A CASE STUDY OF THE SONGLIAO BASIN
Liu Cuirong, Chen Fajing
1996, 18(3): 274-282. doi: 10.11781/sysydz199603274
Abstract:
Two kinds of theoretical geodynamic models (the uniform extension model and thenon-uniform extension model)of extensional basins were used to simulate the observed tectonic subsidence of the Songliao Basin to discuss the mechanism of extensional basins. Byfitting it with actual measured data,he genetic mechanism and evolution history of thebasin can be further recognized.Especially,the quantitive parameters of basin evolutionprocess such as extension quantity,tectonic subsidence,paleo-heat-flow,paleotemperatureand vein intrusive amount can be calculated.
THE STRUCTURAL CHARACTERISTICS OFTHE MINHE BASIN
Zhang Huquan, Yang Zhongxuan
1996, 18(3): 283-288. doi: 10.11781/sysydz199603283
Abstract:
Based on analysis of seismic, gravitative and magnetic, and outcrop data, the dualstructures of the Minhe basin were recognized. The basin underwent an early graben stage(before deposition of the Upper Cretaceous) and a later depression stage (after depositionof the Lower Cretaceous). It was an inter-mount fault depression developed during theMeso-Cenozoic. Basement of the basin is a compound one,consisting of the Pre-Cambrianmetamorphic rocks and the granites of the Caledonian fold belts. Six different kinds of localstructural patterns were included in three main structural compositions of shear,overthrustand basement growing.
ORIGIN, DISTRIBUTION AND FORMING CONDITIONSOF SAND-CONGLOMERATE BODIES IN THE AREA 2&3 OFGAOSHENG OILFIELD, THE WESTERN LIAOHE DEPRESSION
Dong Chunmei, Lin Chengyan, Hou Lianhua, Xin Quanlin
1996, 18(3): 289-297. doi: 10.11781/sysydz199603289
Abstract:
The Lianhua sandstones 5、6 in areas 2、3 of Gaosheng oilfield in the western Liaohe depression were discussed in this paper. On the basis of study of cores, various geneticcriteria and the quantitative logging information, using method of sedimentary microfaciesfor reservoir development, a braided channel model of gravity flows in deep lacustrine environment was built and the spatial distribution and evolution of the sand-conglomeratebodies were clarified. It was pointed out that reservoir properties were controlled by sedimentaty factes. In addition, the relationship among the formation of the sand-conglomerate bodies of the braided gravity flow channel in the deep water, fault structures, palaeoclimate and palaeotopography was disscussed.
LATERAL ACCRETION CROSS-BEDDING:THE MAIN TYPE OF SEDIMENTARYSTRUCTURES IN THE BRAIDED CHANNEL
Li Weifeng, Gao Zhenzhong, Peng Detang
1996, 18(3): 298-302. doi: 10.11781/sysydz199603298
Abstract:
Lateral accretion cross-bedding results from lateral accretion of sand bodies induced bythe lateral migration of channels and is very abundant in the braided channels. Its characteristics are: ① the overall shape of its sets is tabular, but its laminae are sigmoid, clearlyconverging both upward and downward. ② there is secondary cross-bedding or crosslaminations as well as slump structures in the inner part of some‘laminae'. ③ the setthickness has nothing to do with the grain size of the sediments. ④ the thickness, grainsize and composition of each lamination within the same set are significantly different eachother. ⑤the laminae dip is at approximate vertical angles to palaeocurrent direction. Thelateral accretion cross-beddings are very abundant in the braided channel as there are moretransverse circulation flows in it and more sand and less mud in the sediments.
GENETIC MECHANISM OF ABNORMALFORMATION PRESSURE OF KUIHUADAO STRUCTURE
Li Yuzhan, Wan Zhimin, Yang Huaiyi, Xie Wenyan, Ma Changxin, Li Mingge
1996, 18(3): 303-310. doi: 10.11781/sysydz199603303
Abstract:
Overpressure in Shahejie formation of Kuihuadao structure was occurred in the end of deposition of Dongying formation. Closed faults were the first condition for occurrence of overpressure, and continuous accumulation of gas was the important factor for overpressure. And fast deposition of sediments, dehydration of clay minerals and heat pressureboosting also had some contribution to the abnormal formation pressure.
DEPOSITIONAL ENVIRONMENTS OF LACUSTRINE OILSHALES AND ITS SEQUENCE STRATIGRAPHY SIGNIFICANCE
Liu Li, Wang Dongpo
1996, 18(3): 311-316. doi: 10.11781/sysydz199603311
Abstract:
Lacustrine oil shales can be divided into shallow lake and deep lake deposits in termsof their sedimentary environments. The former can be playa, ectogenic meromictic andshallow saline lakes; and the later is related to stratified lake. The oil shales are located inthe middle part of a transgressive-regressive cycle (whose scale is variable), whether theyare shallow or deep lake oil shales in origin. As one of condensated sections of continentalstrata, if oil shales can be marks between transgressive system tract and highstand systemtracts (the maximum flooding surface or the maximum flooding zone) depends on their position in the sequence and on if there is other condensated section above the shales.
A STUDY ON SECONDARY PORES OF THE MESOZOICSANDSTONES IN THE TURPAN-HAMI BASIN
Liu Linyu
1996, 18(3): 317-324. doi: 10.11781/sysydz199603317
Abstract:
The secondary pores of the Mesozoic sandstones in the Turpan-Hami basin weremainly formed by the dissolution of unstable components of sandstones. The secondarypores were distinguished to be of eleven types in three developmental zones The formationand preservation of the effective sandstone bodies. the diagenetic evolution of organic material and clay minerals in mudstones, and dissolution of unstable components in sandstones are the main cause for the formation of the solution pores.
CLASSIFICATION OF ORGANIC MACERAL IN CARBONATES
Qin Shengfei, Zhong Ningning, Qin Yong
1996, 18(3): 325-330. doi: 10.11781/sysydz199603325
Abstract:
Based on study method of organic lithology, Samples from an evolutional sequence ofcarbonates in northern China were studied in detail on the Principle of simplicity, practicality and systematization. The organic matters in carbonates were classified into 3 types:allogenic, autogenic and secondary ones according to their characters, origin, sedimentation and msturation. Each kind of organic matters was subdivided into maceral suite, maceral and sub-maceral.
THE FEATURE AND MEASUREMENTMETHODS OF POROSITY ANDRELATIVE PERMEABILITY OF COAL RESERVOIR
Hou Ruiyun
1996, 18(3): 331-335. doi: 10.11781/sysydz199603331
Abstract:
Coal gas reservoir is different from conventional gas reservoir.Coal is not only sourcerock but reservoir as well. As reservoir. there is special feature in pore texture in coal.And mechanism of accumulation and occurrence of gas in coal is also different from thoseof conventional gas reservoir on basis of comparison of coal gas reservoir with conventionalgas reservoir. the paper discussed the feature and measurement methods of porosity andrelative permeability of coal reservoir.
APPLICATION OF FLUID'S OWN MICROCOSMICINFORMATION TO DETECTING HYDROCARBONPRESERVATION IN OIL/GAS FIELDS (ACCUMULATIONS)
Rao Dan
1996, 18(3): 336-343. doi: 10.11781/sysydz199603336
Abstract:
Based on study and summary of geochemical characteristics of fluid (oil,gas and water) in Wolonghe gas field (including Jiannan field) of the Sichuan basin and Yakela typical block uplift gas fields (Yakela condensate field and Tiergen field) of the Tarim basin,the author considered that fluid's own microcosmic information could more directly revealsituation of oil and gas preservation than the objective environment, thereby do more accurate evaluation of regional hydrocarbon preservation.