Table of Content

25 March 1995, Volume 16 Issue 1

Previous Issue    Next Issue

IMMATURE SOURCE ROCKS OF FUTAN GROUP IN FUJIAN AND HYDROCARBON POTENTIAL ANALYSIS OF XIAMEN-PENGHU DEPRESSION IN TAIWAN STRAIT

Zhi Jiasheng, Li Yulin, Luo Jindin, Li Guanfu

1995, 16(1):  1-10.  doi:10.11743/ogg19950101

Asbtract ( 748 )   PDF (8291KB) ( 569 )  

Related Articles | Metrics

When the vitrinite reflectance of source rock in the Futan Group is 0.3%(R_o),the resinite and alginite contained in the source rocks may form light crude oil and natural gas.This part of resource extent must be considered in oil and gas exploration.Futan area is located in the west margin of Cenozoic Xiamen-Penghu fault depression,and the major sag in the depression contains nearly 5000m thick Tertiary deposits of terrestrial-neritic factes.Thus Futan area possess good potential of immature-high mature oil and gas.

FAULT STRUCTURAL STYLES IN TARIM BASIN AND THEIR RELATION WITH HYDROCARBON

Gong Ming, Shao Hongliang, Wu Hong, Duan Tiejun, Wang Zehou

1995, 16(1):  11-21.  doi:10.11743/ogg19950102

Asbtract ( 790 )   PDF (10250KB) ( 617 )  

Related Articles | Metrics

There are 8 fault structural styles in Tarim Basin and its periphery.Some of them are ofthe caprock detachment origin which include imbricate thrust, passive roof recoiled thrustand ramp structures developed mostly in Kuche marginal foreland basin and the back-arcforeland basin of Southwest Tarim Basin,and are related to detachment sequences andsedimentary-structural loading in the above mentioned two basins.Others belong to basement involved type that include back thrust,thrust,strike-slip,homodromous fault blockand graben structures developed mainly in the internal palaeo-uplifts in Tarim Basin or onthe transform margins in geological history.Among the styles,the back-thrust,imbricatethrust and duplex thrust structrues are more important to hydrocarbon exploration.

MICROPETROLOGICAL CHARACTERISTICS AND HYDROCARBON-GENERATING POTENTIAL OF DIFFERENT REDUCTING TYPE VITRINITE IN JIANGSU-SHANDONG

Li Xianqing, Zhao Shiqing

1995, 16(1):  22-30.  doi:10.11743/ogg19950103

Asbtract ( 663 )   PDF (8108KB) ( 613 )  

Related Articles | Metrics

The micropetrological characteristics and hydrocarbon-generating potential of different reduction type vitrinite collected in Jiangsu-Shandong were studied.The results show that the vitrinite of strong reduction type is much different from that of weak reduction type.The former has rich fluorescent vitrintite,lower reflectance,stronger relative fluorescence intensity,less spectral maximum,higher yields of chloroform bitumen and oil potential,especially R_o ranges from 0.6% to 0.9%.All of them suggest that the vitrinite of strong reduction type is relatively rich in hydrogen,and has higher hydrocarbon generation potential,particularly for liguid hydrocarbon potential.Therefore,this type of vitrinite is an important parent substance of oil generauon for strong reduction type humic coal.

SEDIMENTARY ENVIRONMENT AND ITS EVOLUTION OF CHANGFANGGOU GROUP IN DALONGKOU REGION

Lou Zhanghua, Zhao Xiafei, Liu Zhigang, Wang Yao

1995, 16(1):  31-38.  doi:10.11743/ogg19950104

Asbtract ( 669 )   PDF (14906KB) ( 725 )  

Related Articles | Metrics

The Changfanggou Group(P₂-T₁),developed at the east part of Junggar is represented by some 1000m of elastic sediments which comprises fluvial-fan factes,meandering stream factes and low-sinuosity stream facies,braided stream factes and lacustrine fade.Sedimentary properties and the changes in fluvial styles reflect an increasing aridity and decreasing flora population under cyclic tectonic active condition during P₂-T₁ period.The changes in paleoclimate and paleotectonics resulted in the variation of sedimentary environment.The variation from meandering stream to low-sinuosity stream was a process from warm and humid climate,luxuriant plants to hot and semiarid climate, nonvegetation enveronment.The low sinuosity streams become braid streams and wedge-shaped braid factes developed in the study area with the uplift of provenance.

POROSITY OF OIL-ENTERING PERIODS AND RESERVOIR ROCK TYPES OF CARBONIFEROUS IN CENTRAL HUBEI DEPRESSION

Wang Huamin, Ai Huaguo, Lui Lanlan

1995, 16(1):  39-44.  doi:10.11743/ogg19950105

Asbtract ( 614 )   PDF (6033KB) ( 427 )  

Related Articles | Metrics

The oil-entering periods of the Carboniferous in Central Hubei Depression could mainly be divided into two stages:Indo-China and Yenshan Epoches.The porosity types during the periods consists of exposed corrosion porosity in early stage,shallow-layer corrosion porosity and deep-seated corrosion porosity in the late stage.The reservoir rocks corresponding to the porosity types include:1.powder-fine crystal dolomitite;2.microspar dolomitite(or microsparite);3.dolomitite that is formed of blue-green algae and foraminifer;4.micritic breccia dolomitite;5.micritic limestone.Dolomitites in the lower part of the Carboniferous Huanglong Formation is the main reservoir bed among all in this region since it has more types of reservoir spaces and higher porosity during the periods;the secondary one is the microspar granular limestone in the upper part of the formation.

STRATIGRAPHIC CLASSIFICATION AND CORRELATION OF 1ST SUBMEMBER OF 5TH MEMBER,UPPER MAJIAGOU FORMATION IN EAST MARGIN OF SHAANGANNING BASIN

Xu Lunxun, Wang Baoqing

1995, 16(1):  45-54.  doi:10.11743/ogg19950106

Asbtract ( 796 )   PDF (8976KB) ( 624 )  

Related Articles | Metrics

The 1st submember of the 5th member of Upper Majiagou Formation in the Lower Or dovician is the main reservoir of Shaanganning Basin,and its subdivision and corrlation with subsurface counterpart within the basin benefit the establishment of nonhomogeneous geo logical model.Based on the study of the outcrop in Guanjiaya, Xingxian of Shanxi Province.gypsum.pseudocrystal layer(K₁) and tuff layer(K₂) were selected as the main marker horizons,and the argillaceous rock ina,b,c suites of carbonate rocks as subsidiary marker horizions,then the first submember(M5₁) could be subdivided into four beds(M5₁¹,M5₂¹,M5₃¹ and M5₄¹),the result suggest that the bounderies of the beds correspond with the peaks of the curves of their chemical elements,and the beds constitute different clay mineral assemblages.M5₁¹ is rich in kaolinite,poor in illite and has no chlorite;M5₂¹ has plenty of illite and kaolinite but no chlorite;M5₃¹ contains almost no clay minerals;in M5₄¹,kaonite,illite and chlorite could all be found.The different marks and characteristics of the four beds could be seen clearly in well drilling within the basin.therefore they may be considered as foundation and markers for bed subdivision and correlation.

PROPERTIES OF EOGENE SEDIMENTARY SYSTEM IN YISHU GRABEN AND ITS HYDROCARBON SIGNIFICANCE

Zhou Yongshen, Wang Dongpo, Kuang Lichun, Zhang Weiliang, Han Jun

1995, 16(1):  55-62.  doi:10.11743/ogg19950107

Asbtract ( 621 )   PDF (6707KB) ( 743 )  

Related Articles | Metrics

Braided delta system and sublacustrine fan system constitute the primary Eogene coarse elastic sediments which are characterized mainly by short axial direction transportation depositlon.The asymmetrical bilateral fractures whthin the graben resulted in the drift of subsidence center and depocfnter towards the main fracture;the braided delta system then developed on the gentle slope.As the main reservoirs in the graben,the development of the braided delta system was closely related to its transverse structtyres such as cross faults,fault benches, borderland slopes and basement uplifts.Thus these structures should be im portant targets for oil and gas exploration.

DOWNHOLE GEOCHEMICAL EXPLORATION:A NEW REALM OF OIL AND GAS EXPLORATION

Chen Li, Cheng Zhichun, Wei Wei

1995, 16(1):  63-75.  doi:10.11743/ogg19950108

Asbtract ( 633 )   PDF (10311KB) ( 480 )  

Related Articles | Metrics

By using synthetic assessment and interpretation of downhole geochemical exploration,this paper proposed following methods such as the analogy-foil method of both key horizon and marker horizon which could be used to check the effectiveness of geochemical exploration index; the probability analysis for oil and gas reservoir prospercting; the method to analyse hydrocarbon superimposition intensity and the density gradient of hydrocarbon gas; Paxle graphic method for hydrocarbon-bearing formation evaluationl triangular diagram;light alkane ratio;D-function analysis.According to the methods mentioned above,the model of geochemical exploration anomoly for hydrocarbon generation and reservoiring was established in this paper.

EVALUATION OF STRUCTURE-TRAPED OIL AND GAS IN YIKESHU REGION BY GREY SYSTEM THEORY

Guo Shaobin, Zhu Jianwei, Du Xudong

1995, 16(1):  76-80.  doi:10.11743/ogg19950109

Asbtract ( 604 )   PDF (3764KB) ( 635 )  

Related Articles | Metrics

Based on the study of the controlling factors and the distribution regularity of oil and gas in Yikeshu region,seven parameters were chosen to evaluate the structural traps in the region by adopting grey associative system theory.The results are consistent with the information from drilling.It thus proposed that No.13 and No.14 traps should be the key targets for further exploration.

STRATIGRAPHIC SEQUENCE OF LOWER CRETACEOUS IN SOUTHERN SONGLIAO BASIN AND ITS PERIPHERY

Lin Zongman, Ren Chuanhui, Zhang Pulin

1995, 16(1):  81-88.  doi:10.11743/ogg19950110

Asbtract ( 714 )   PDF (7315KB) ( 625 )  

Related Articles | Metrics

Stratigraphic repetation exists in deep-seated lower Cretaceous Series inthe southeast rise of the Songliao Basin.The acid volcanic rocks of the Yingcheng Formation intrude the Shahezi Formation instead of intercalation.This kind of intrusion can be seen on both surface profiles and seismic profiles in Santai,Guanmashan-Huihuiying areas in Jiutai County.The Yingcheng coal-measures as were called before is acturally the Shahezi Formation.It thus conclude that there was only Shahezi Formation in the study area in Early Cretaceous basining period which corresponds with the Aobao and Denglouku Formations in central depression.According to the above mentioned,the Aobao and Denglouku Formations may possibly be the most important deep-seated hydrocarbon source beds in the central depression of the Songliao Basin.