1988 Vol. 10, No. 3

Display Method:
THE EVOLUTION OF CHINESE PLATE AND ITS PETROLIFEROUS BASINS
Wu Shoucheng
1988, 10(3): 197-212. doi: 10.11781/sysydz198803197
Abstract:
Chinese Plate (the mainland of China) which is a part of Eurasian, mainly consists of the Tarim Sinokorean and South China, as well as parts of Siberian-Kazakhatanian and Indian plates. Previous to the formation of Chinese Plate during Indosinian stage, the structural frame-work was EW trending mainly with marine sedimentary formation due to hot baryshere flow, brought about latitudinally spreading of sea floor to north and south. Subsequently,the oceanic ridge expansion took place and resulted into the formation of SN structural framework principally with non-marine sedimentary formation. Post to the formation of Chinese Plate,the basins of the eastern part of the plat (eat 15°-43° from tropic to temperate and frigid zones) are mostly of thermally extensionai basins under the effectness of new-born Pacific Plate, while those of the western part of the plate are cooly compressional basins influenced by Tethys. In a view of Chinese Plate movement as a whole,there are different characters in the individual plate movements which reflect various paleogeographical environments and the conditions for oil/gas generation. Generally speaking, petroliferous basins would develop at the interior of plate,and basin boundary and oil/gas boundary are both controlled by plate movements and the rework on them. Meanwhile, the distribution of oil/gas fields would be related to the center of oil generation. The migration traces of the depocenter and the depositional boundary for a large basin are supposed to be coincided with those of a plate. Therefore, it is practically significant in this study.
ON OIL AND GAS PROSPECTS OF DABA AREA
Gao Changling
1988, 10(3): 213-220. doi: 10.11781/sysydz198803213
Abstract:
The author of this paper studies the tectonic evolution of Qingling-Daba Region and the organie geochemical characteristics of the source rocks in the area.More detail analysis have been made on the evolutionary regularities of the source rocks during the time of the tectonic development. It comes to the following conclusions. 1.The auiacogen there is a typical paleozoic protobasin developed from Sinian to Triassic time. The evolution of the basin can be devided into three stages and subdevided into six episodes.The source rocks developed mainly from Cambrian to Silurian (the most active growing period of the aulacogen) are claystones and carbonate rocks with a large thickness, high organic content,excellent kerogen type and high oil/gas generating potential. Although the organic matter is locally overmature, it is considered that the southern flank of the aulacogen and the adjacent part of Yangtze Platform are the favourable area for oil/gas exploration 2.The southern Shaanxi-northeastern Sichuan overthrust system is a major system. Its history of development and formation can be devided into 4 stages and the main stage is from Late Yenshanian to Himalayan time. It is believed that such a overthrust system is a significant frontier for oil/gas exploration.
1988, 10(3): 221-222. doi: 10.11781/sysydz198803221
Abstract:
STUDY ON THE DIAGENESIS OF CLASTIC OIL FORMATION ASSEMBLAGE
Zhu Jiaxiang, Li Shuzhen
1988, 10(3): 223-240. doi: 10.11781/sysydz198803223
Abstract:
The first member of Dainan Formation(E1d1)in Gaoyou Depression, Northern Jiangsu can be devided into high, middle and low evolutionary zones in which the depth for the middle evolutionary zone is of 2800m-3300m. Its organic matter has evoluted to early and middle maturation stages. So that a large amount of low-mature oil was generated and subsequently migrated into sandstone belt with first secondary porosity created by the formation water released from clays. The depth of the high evolutionary zone is about 3300m-4000m where highly mature oil and condensate gas were generated at the later stage of maturation. Thereafter, the oil/gas migrated to the belt with second secondary porosity along the microfractures in claystones,and such a zone would be a favourable interval with a significant oil/gas potential.
ELECTRON PROBE ANALYSIS ON THE DIAGENETIC CHARACTERISTICS FELDSPAR AND QUARTZ
Fang wei, Xue Zhongzhou
1988, 10(3): 241-247. doi: 10.11781/sysydz198803241
Abstract:
Based on the properties of reservoir rocks, the authors of this paper advance the methodology of the study on the diagenesis of feldspar and quartz in reservoir rocks with developed functions using reformed electron probe. It is revealed that secondary porosity of reservoir rocks are mainly resulted from potash feldspar dissolution. The microelement content of the secondary enlargement margin of the the feldspar and quartz, somehow, would reflect the chemical conditions of the pore fluids during diagenesis. Therefore, it can be used as an auxiliary tool to classify diagenetic stages, and it will provide leads and explore avenues for the further studies on reservolr rocks.
RELATIONSHIP BETWEEN THE INJECTED BASALT IN QINGSHANKOU FORMATION AND OIL/GAS IN ZHONGYANG DEPRESSION, SONGLIAO BASIN
Han Guangling, Zhao Hongtao, Bian Wen
1988, 10(3): 248-255. doi: 10.11781/sysydz198803248
Abstract:
The Cretaceous Qingshankou Formation of Songhuajiang Group comprises the main source rocks of Songliao Basin. It is proved that basalts have been injected into this formation in Qianan and Taikang areas of the central depression zone. The authors of this paper approach to the relationship between the distributive characters of the basalt and oil/gas. It is considered that axial injection and eruption of the basalt occurred along the heigh-tened Moho discontinuity of the basin during the late sedimentation stage of Qingshankou Formation. The seismic waves have rather high velocity in the basalt area and constitute dune reflective configurations. The logging curves in the basalt area are characterized by "one high and three lows". Generally speaking, drag structures related to the basalt eruption would develop beneath the basalt body while primary structures related to the dune configuration and differential compaction would develop above the basalt body. Therefore, such an area would be favourable for the traps of oil/gas. In addition, gentle baking of the source rocks by the basalt eruption and injection would improve the prospect for oil/gas exploration.
CHARACTERISTICS AND DISTRIBUIVE REGULARITY OF THE OILS WITH LOW AND HIGH SOLIDIFICATION POINTS IN DAMINGDUN DEPRESSION
Zheng Rongzhi, Wang Guizhen
1988, 10(3): 256-267. doi: 10.11781/sysydz198803256
Abstract:
According to the characteristics of solidifreation point, wax content, etc., the crude oils in Damingdun Depression can be devided into high solidjfrcation point oil and low solidijication point oil, thinned oil and mixed oils, among which the high solidification point oil is dominant. It is rich in paraffin and ozokerite with wax content higher than 30% and high solidification point over 40℃, even up to 69℃. It differs from normal thickened oil (heavy oil) and can be attributed to low mature unoxidized primary oil. The low solidification point oil solidifies below 0℃, even down to -40℃. It has high specific gravity and viscosity, high contents of resin and asphaltene,high primary distillation point,and low soli-dification point, low wax content and light fractions. Therefore, it belongs to secondary biodegraded oil. The wax content of the thinned crude oil which belongs to waxy oil with low sulfur content is less than 15% while its hydrocarbon content can be 68.6%. The last type of the oils is the mixed oil of different ratios of thinned oil and high solidification point oil and the properties of the mixed oil are between these two oils. The source rocks of the high solidification point oil mainly are of Es4 dark claystones and the distribution of the oil is controlled by the source rock and faulting activities. The various types of crude oil layers in the depression are overlapped each others and according to the ordersfrom lower to upper oil layers, they respectively contain high solodification point oil, mixed oil, thinned and low solidification point oil. Howevev, the low solidification point oil is emplaced in shallow buried rocks of younger age while high solidification point oil is emplaced in relatively deep buried rocks of older age.
STUDY ON RELATIONS OF SEDIMENTARY MODEL OF SALT LAKE BASINS TO OIL/GAS EXAMPLIFIED BY THE GOCHEMICAL CHARACTERISTICS OF THE RECENT SEDIMENS OF DABUSU LAKE
Wu Deyun, Zhang Guofang, Liu Chongxi
1988, 10(3): 268-276. doi: 10.11781/sysydz198803268
Abstract:
The authors investigated the geology, geomorphorphology,hydrology, hydrologic chemistry and sedimentation of Dabusu Lake Basin, so as to understand the intrinsical relations and interactions of hydrologic geochemical conditions and organic evolution. Eventually, relationship of sed-imentary model to oil and gas in salt lake basins are discussed.
GEOCHEMICAL CHARACTERISTICS OF ORGANIC COMPOUNDS IN FIELD WATER IN QIANJIANG DEPRESSION
Lin Qiuhao, Wen Zhigang
1988, 10(3): 277-283. doi: 10.11781/sysydz198803277
Abstract:
The paper mainly deals with organic compounds in oil field water in Qianjiang Depression. The distribution of carbon number and odd-even predominance of fatty acids, heavy hydrocarbons/light hydrocarbons and iC4/nC4 ratio in oil field water,are meaningful in determinng the organic types of source rock and its maturity.
ANALYTICAL TECHNIQUE OF TRACE METAL ELEMENTS IN ORGANIC EXTRACTS OF CARBONATE ROCKS
Shi Chao, Xiao Chulin, Cao Heying, Zhuang Yuren
1988, 10(3): 284-288. doi: 10.11781/sysydz198803284
Abstract:
Using microanalytical method, experiments are made on determination of trace metal elements in organic extracts of carbonate rocks. The paper discussed in detail onthe whole procedure of experimental analysis and various analytical conditions.
SPOROPOLLEN COLOUR AND THE ORGANIC ATTER TYPE OF LOWER CRETACEOUS SOURCE MROCKS IN ZHOUKOU BASIN, HENAN PROVINCE
Wang Congfeng, Zeng Guangyan
1988, 10(3): 289-303. doi: 10.11781/sysydz198803289
Abstract:
The Zhoukou Basin is located at eastern part of Henan Province where Lower Cretaceous is well developed. According to the microscopic observations on the sporopollen colour and the organic debris taken from the drilling cores, the evolution of the organic matter can be devided into 4 stages, i·e·immature, mature, highly mature, and over mature.