1995 Vol. 17, No. 3

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PRELIMINARY ANALYSIS ON THE EXPLORATION PROSPECTS OF NATURAL GAS RESOURCES IN JUNGGAR BASIN
Liu Donghai
1995, 17(3): 215-219. doi: 10.11781/sysydz199503215
Abstract:
In this paper, the main exploration achievements, basin modelling, inhorn characteristics, exploration prospects and beneficial exploration areas of natural gases in Junggar Basin are detailed discussed. It is pointed out that the exploration prospects of natural gases in Junggar Basin are broad, the research of natural gases must be strengthened unceasingly and the exploration of natural gases be laid stress on, and the research, exploration and development of non conventional natural gas resources must be enhanced especially.
THE CHARACTERISTICS OF SEDIMENTARY FACIES AND THE CONDITIONS OF STORAGE AND ACCUMULATION IN THE LOWER CRETACEOUS SERIES OF TARIM BASIN
Chen Yue
1995, 17(3): 220-228. doi: 10.11781/sysydz199503220
Abstract:
Lower Cretaceous deposit is an important hydrocarbon bearing horizon of Tarim Basin. In this paper,more systematic and detailed research is carried out on the sedimentary facies of Early Cretaceous strata, and the oil/gas prospects of Lower Cretaceous series are also expounded from various respects as the characteristics of sedimentary facies and reservoir rocks and so on.
DIVIDING THE TRAP TYPES OF TARIM BASIN ACCORDING TO CONFINING MECHANISM
Dong Xiufang, Wu Hong
1995, 17(3): 229-237. doi: 10.11781/sysydz199503229
Abstract:
At present, the exposition of most articles on traps lays particular emphasis on the respect of forming mechanism. In this paper, the trap types of Tarim Basin are preliminary divided into two categories and six subcategories according to confining mechanism (i. e. the patterns to confine oil/gas). The two categories are monoconfining layer traps and multiconfining layer traps; and the six subcategories include conformable types (C-type), unconformable types (U-type), conformable+fault types (CT-type). unconformable+fault types (UT-type), conformable-(-unconformable types (CU-type)and conformable+facies change types (CFC-type). Generally speaking, the monoconfining layer traps between the two categories should be the most beneficial type to the storage and accumulation of oils and gases. Among the six subcategories, C-type traps have the best ability to storage and accumulate oils and gases.
TECTONIC ELECTRICAL CHARACTERISTICS AND A-MODEL SUBDUCTING PATTERNS OF SOUTHWEST TARIM BASIN-WEST KUNLUN AREA
Lu Xinbian, Shi Yan, Tian Qulai
1995, 17(3): 238-248. doi: 10.11781/sysydz199503238
Abstract:
Based on the explanatory results of two magnetotelluric sounding profiles which connect the folded belts of Southwest Tarim Basin with West Kunlun. the geoelectric tectonic characteristics of lithosphere along the measuring areas are studied and analysed. It is pointed out that the width of nappe is about 40km and the nappe distance from south to north is more than 20km within the larger-scale developed overthrust nappe tectonic belt on the southwest edge of Tarim Basin. Moreover, tectonic units are divided and the tectonic contact relations of each unit are approached according to electrical data. Lastly, by means of comprehensive analyses on the characteristics of isostatic gravity anomaly, seismic activity etc. of this area, the intracontinental subducting patterns between Southwest Tarim Basin and West Kunlun are studied and established, and the viewpoint and cognition that the nappe tectonics extensively present in the area relate to intracontinental sub-duction existing in deep earth crust are suggested.
TECTONIC CHARACTERISTICS AND HYDROCARBON PROSPECTS OF SOUTHEAST TARIM BASIN
Pu Renhai, Che Zicheng, Ren Zhanli
1995, 17(3): 249-258. doi: 10.11781/sysydz199503249
Abstract:
Stratigraphic contact relations and regional depositional characteristics imply that the southeastern part of Tarim Basin, like the whole Tarim Basin, has undergone three evolutional stages——Paleozoic platform, Misozoic fault depression and Cenozoic depression.Since early Paleozoic era, five distinct regional tectonic movements have occurred in this area. According to the characteristics of basement depth, deep faults and Stratigraphic thickness and distribution, Southeast Tarim Basin can be divided into two major tectonic units and eight secondary structural units. The prospective hydrocarbon blocks lie to the west of Qiemo.
CHARACTERISTICS OF DIAPIRIC STRUCTURE AND ITS FORMATION MECHANISM IN WANGJI AREA OF BIYANG DEPRESSION
Wei Xinshan, Zheng Qiugen, Zhang Zhiye
1995, 17(3): 259-264. doi: 10.11781/sysydz199503259
Abstract:
Wangji Oilfield is an oilfield which has been put into development. By studying on the fault series of grabens, nose, the characteristics of sedimentary facies and the reflection characteristics of seismic profiles in Wangji area, the authors suggest a new cognition that the master tectonic of Wangji Oilfield is in fact a mud diapiric structure. This cognition will have practical significance to the study of reservoir distributive regularity and further exploration and development in Wangji Oilfield.
GEOCHEMICAL STUDY OF OIL/GAS MIGRATION ON THE NORTHWEST EDGE OF JUNGGAR BASIN
Wang Yutao, Hui Rongyue
1995, 17(3): 265-271. doi: 10.11781/sysydz199503265
Abstract:
Taking the oil pool profiles of No.8-No.6 regions on the upper and lower plates of Ke-Wu Fracture on the northwest edge of Junggar Basin for example.thirteen Permian-Jurassic crude oils are sysematically sampled in this paper,and the physical and geochemical properties of crude oils are analysed, it is revealed that the crude oil density of No.8-No.6 regions gradually increases and polar compounds, low-molecular isohydrocarbons and pregnanes in the components of biomarkers are gradually enriched along the oil pool profiles ;besides.varied systems could exist during migration,that is to say.low carbonate hydrocarbons are caused molecular diffusion by decreases in temperature and pressure and the relative openness of systems,high carbonate polycyclic naphthenes are led to the frac tional distiolation of compounds due to stratiform segregation, and microbial degradation occurs in shallow reservoirs. The geochemical characteristics of oil/gas migration rule out the possibility that there are sourcelands within oil areas and further evidence that Lake Ma Depression is the oil source area of Ke-Wu Fault Terrace zone.
LACUSTRINE CARBONATE SOURCE ROCKS AND THEIR ORGANIC GEOCHEMICAL CHARACTERISTICS——TAKING THE TERTIARY SYSTEM OF QAIDAM BASIN FOR EXAMPLE
Tuo Jincai, Shao Hongshun, Huang Xingzhen
1995, 17(3): 272-276. doi: 10.11781/sysydz199503272
Abstract:
The characteristics of lacustrine carbonate type source rocks are thai in the rorks the content of carbonate is high,the content of organic carbon is low.but the transformation ratio of their organic material to soluble hydrocarbons is higher. The distributive character istics of biomarkers in their soluble extracts are very similar to those in carbonate rocks and evaporite rocks series.
REVERSAL OF VERTICAL ZONING IN DEEP HYDROGEOCHEMISTRY
Guo Qijun, Jiao Shouquan, Wan Zhimin
1995, 17(3): 277-280. doi: 10.11781/sysydz199503277
Abstract:
Recent petroleum exploration has revealed that the vertical zoning in the hydrogen chemistry of oil field water in petroleum bearing formations may appear reversed. The main manifestations are that the degree of mineralization reduces when the depth increases, the type of hydrochemistry is a Na-HCO3-type water with rich sodium ions and poor calcium ions,and there is clearly a negatyve correlation between the contents of Ca2+ and HCO3 ions. These characteristics are more obviously near petroleum gathering areas. So a thorough study on them will provide beneficial information for petroleum exploration.
THE TYPES OF FISSURE AND THE MIGRATION AND ACCUMULATION OF NATURAL GASES IN THE CARBONATE ROCKS OF LOWER PERMIAN SERIES IN SOUTH SICHUAN
Hu Zhishui, Chen Qinfang, Tong Chongguang, Peng Dajun
1995, 17(3): 281-285. doi: 10.11781/sysydz199503281
Abstract:
Based on the study on the drilling geology,outcrop sections and petrology characters tics of carbonate rocks in the Lower Permian series of South Sichuan,the authors discuss all sidely fissure types and fissuring mechanism in the fissure reservoirs of carbonate rocks and their significance to the migration and accumulation of natural gases.
THERMAL MODELLING RESEARCH OF CLAY MINERALS
Zhou Guoqing
1995, 17(3): 286-292. doi: 10.11781/sysydz199503286
Abstract(1053) PDF-CN(777)
Abstract:
In this paper,the method and results of three thermal modelling experiments on clay minerals are introduced; the one under normal pressure and varing heating temperature.the one with different heating time and the one under high pressure and varing heating temperature in alkaline mediums. Besides,the effects of temperature and sustained heating time on clay minerals,the relation of clay dehydration to hydrocarbon migration and the changes of clay minerals under high temperature and pressure are also discussed. The author considers that temperature and sustained time are the important conditions of mutual compensation during the diagenetic transition of clay minerals, and the pressure is a secondary factor. The conversion of montmorillonite to illite is advantageous to the increase of porosity and permeability.
APPLYING OF BIDIRECTIONAL MONOENTRANCE VARIANCE ANALYSIS TO THE QUALITY ADMINISTRATION OF OIL/GAS GEOCHEMICAL EXPLORATION ANALYSIS
Jiang Qigui
1995, 17(3): 293-295. doi: 10.11781/sysydz199503293
Abstract:
In this paper,the method of bidirectional monoentrance variance analysis is used to examine the quality of analytical data. It can be observed clearly the effects of the real changes and error changes of sample contents on the total changes of sample contents during analysis.It also can be found out if accidental errors and systematic errors exist and if they will shelter or distort the real contents of samples in the course of analysis.
A MICROCOMPUTER PROCESSING SYSTEM OF IR(UV) SPECTRAL DATA
Guo Shuiyin, Nian Luwen
1995, 17(3): 296-300. doi: 10.11781/sysydz199503296
Abstract:
This system reforms the older generational non-computerized grating spectrograph. By connected with a microcomputer, it realizes the computerization of spectra and spectral datum collecting and processing. This set of system includes more than ten functions; the collecting.display and storage of spectra and data, the selecting of absorption peaks, the processing (enlarging, comparing and arranging) of spectra, the shifting of coordinates and so on. The system adopts a structuralized editor program to merge spectra and datum processing into an organic whole, and uses complete Chinese prompting characters and the form of man machine conversation to operate. It is not only flexhle to he used by, but also simple to be operated with. Also, it has strong practicality and transplantahilily. and is easy to speread.
STUDY ON STEROIDS IN TERTIARY WOOD COAL FROM NANNING BASIN BY THERMAL-MODELLING EXPERIMENTS
Xia Yanqing, Luo Binjie
1995, 17(3): 301-309. doi: 10.11781/sysydz199503301
Abstract:
In this paper, the occurrence of steranes and their thermal evolutionary patterns are approached based on the results of thermal-modelling experiments. Different steranes have different occurrence. Regular steranes, rearranged steranes and 4-methyl steranes mainly come from the transition of non kerogen precursors, and the degradation of kerogcn do not generate these compounds basically. However, pregnanes are mostly generated by the degradation of kerogen. All eight parameters most in use, such as aaa(20R)C27,C28,C29% +aa),have multiple solutions. The higher the value of aaa(20R)C29% and the lower the value of the other parameters, the more accurately the parameters indicate the maturity (iow-mature to mature). Otherwise, they have not any indicative significance.