Loading...
Download
Visited
    Total visitors:
    Visitors of today:
    Now online:

Table of Content

    25 March 1987, Volume 8 Issue 1
    THE REGULARITY OF RING DISTRIBUTION OF OIL AND GAS IN DEPRESSIONS
    Chen Daxian
    1987, 8(1):  1-14.  doi:10.11743/ogg19870101
    Asbtract ( 634 )   PDF (12038KB) ( 380 )  
    Related Articles | Metrics

    In many hydrocarbon basins of the Early Eogene in East China,oil and gaspools have the regularity of ring or semi-ring distribution arround the center ofthe depressions. This is determined by the basic evolution regularity or contem-poraneous fualt-depression. Analyzed the seismic sequence of a typical half-basinin the Bohai Bay Basin, the author suggests that: 1.The evolution process of 4 contemporaneous fault-depression involved sever-al fault-depressed cycles and the rising-dropping periods of water-level. Themain reason that caused the water-level of a inland lacustrine basin to vary wasthe fault subsidence of boundary faults and the aggradation of sediments.Fault-subsidences of rhythmical pulse in association with cyclic wave sedimenta-tion happened througbout tke whole evolution process of the basin. That is tosay, so-called contemporaneous fault-depression basin is composed of several un-contemporaneous stages, and compensation basin is alternatively composed ofmany stages of un-compensation and super-compensation. 2.Each cycle or period of this kind of basin's evolution process included threestages such as fault-depressed, cut-filled and stable deposited stages. These stagesdiffered from one another in dynamic and paleogeography. They controlled thedistribution of traps and reservoirs. In the ring belt closing to depressioncenter, the types are the most varied. 3.Each hydrocarbon basin or depression can be divided into three oil and gasbelts such as central source belt, accumulation ring belt and the surroundingescape belt. Each belt has different pools. Among these belts, the accumulationring belt is the most favourable one. As boundary conditions are different, the ring belts are also varied. They can be subdivided into four kinds as be-low: 1.semiring-Banqiao type; 2. single ring-Baxian type; 3. double-ring-Dong-ying type and 4.multi-ring-Xingang type. It is mostly possible to form hugeoil and gas provinces in the places where two or more ring belts overlapped.4. According to the above version, the guide ideology of oil and gas explora-tion should be ridded from the idea of the secondary tectonic zones which havebeen used for more than 20 years in exploration in East China, and depres-sion should be taken as the basic exploratian unit and research target.

    MIXED SEDIMENTATION OF RECENT CARBONATES AND TERRIGENOUS CLASTICS——Example of the Coral Reef of the Weizhou Island
    Wang Guozhong, Lu Bingquan, Quan Songqing
    1987, 8(1):  15-25.  doi:10.11743/ogg19870103
    Asbtract ( 654 )   PDF (10061KB) ( 378 )  
    Related Articles | Metrics

    The coral fringing reef of Weizhou Island is-based on the volcanic rocks.Except the lower temperature of sea water in winter and vigorous growth ofbrown algae in spring, the environmental factors are suitable for coral growth. This fringing reef is a young one, which has been formed since about 3100years B.P.. Most of the reef-building corals are massive colony which form theframework of the reef. and the branching corals only have a secondary position. There are two provenances of sediments: 1. The coral growing zone and thereef flat is the provenance of fringing reef carbonates, and 2. The sea cliff ofthe volcanic rocks became the provenance of terrigenous clastics. Thase debris aretransported and mixed by the sea currents and tidal energy with lateral and ver-tical migrations in the coastal zone and then accumulated in an asymmetric ringform in plane. The composition of the sediments is mainly consisted of shell debris, coraldebris and terrigenous debris. They are characterized by higher shell debris andlower algal debris, This is the main difference deffering from those of the IndoPacific, the Carribean and other coral reefs in the South China Sea.

    THERMO-DEGRADATION MECHANISM AND HYDROCARBON PRODUCTIVITY OF HUMIC COAL
    Yang Wenkuan
    1987, 8(1):  26-37.  doi:10.11743/ogg19870104
    Asbtract ( 655 )   PDF (11239KB) ( 364 )  
    Related Articles | Metrics

    Based on the statistical data of coal chemistry and coal petrology of 154samples of coal, graphite and vitrinite collected in China, this paper proposesa model of structural formula, thermal evolution process and hydrocarbon pro-ductivity of humic coal, and comes to following conclusions: 1.The typical molecular formuia of Chinese lignite with a vitrinite reflec-tance of 0.359% is C102H96O26. 2.Coalification can be divided into five stages. In the second stage, thebreakaway of methoxyl groups raises the curtain on the formation of hydrocarbon. 3.Under geological condition, the hydrocarbon productivity P2 of residualcoal (water- and ash-free basis) conforms to following equation: p2=402e-2.75(Ro-0.10), (0.30≤Ro<4.80) Where vitrinite reflectance Ro is expressed as percentage, and P2 is m3t-1. Under the condition of simulation test, the hydrocarbon potential P3 con-forms to following equation: P3=598(Ro-0.20)0.55e-1.154(Ro-0.20), (Ro≥0.359).

    INFLUENCES OF MIGRATION ON BIOMARKERS
    Zeng Xianzhang, Liu Shuzhen, Ma Shunping
    1987, 8(1):  38-44.  doi:10.11743/ogg19870105
    Asbtract ( 577 )   PDF (5671KB) ( 842 )  
    Related Articles | Metrics

    The authors studied the biomarkers in Oligocene crude oil and source rocks ofChaheji oilfield ln Hebei Province, and found out that the values or the para-maters such as C21+22 sterane/C27+28+29 sterane, ααα-20S-C29 sterane/ααα-(20R+20S)-C29 sterane, αββ-(20R+20S)-C29 sterane/ΣC29 sterane, rearranged sterane/regular sterane and tricyclic terpane/pentacyclic terpane increase as the migration distance increases.

    CHARACTERISTICS OF GEOLOGICAL STRUCTURES AND HYDROCARBON DISTRIBUTION IN THE BOHAI BAY REGION
    Liu Xingli
    1987, 8(1):  45-54.  doi:10.11743/ogg19870106
    Asbtract ( 577 )   PDF (9362KB) ( 388 )  
    Related Articles | Metrics

    Geological structures in the Bohai Bay region have three different directionsand four structural stacking of uplifts and depressions. Thase structures extended mainly in EW (developed early) and NE(develop-ed late) directions and formed the tectonic framework of alternated uplifts anddepressions in plane while those distributed in NW direction (formed early orlate)are in the second place. Structural stacking of different stages and diffrent directions in space compos-ed four kinds of structure styles including overlapped uplift, overlapped depres-sion, the structures that uplifted first and then depressed and those depressedfirst and then uplifted. Among all these structures, the author suggests that,the overlapped depressions, including Qinan, Dongying, Laizhouwan, theYellow River Mouth and the Bozhong Depression, have the best hydrocarbonpotential; those uplifted first and then depressed and the ones depressed firstthen uplifted are the nextbest. These include the central part of the QikouDepression, the southern part of the Bozhong Depression and the central and northparts of the Liaodong Bay. The overlapped uplifts including the Chengzhikou,Chengbei, Shijiutuo, Bonan-Miaoxi Uplifts and the Fuzhou Depression arethe worst.

    EVALUATION ON THE LOWER WUERHE FORMATION RESERVOIRS IN 8TH DISTRICT, KARAMAY OILFIELD
    Luo Ping, Deng Xunkang, Luo Zhetan
    1987, 8(1):  56-65.  doi:10.11743/ogg19870108
    Asbtract ( 683 )   PDF (8742KB) ( 387 )  
    Related Articles | Metrics

    In consideration of the conglomerate reservoir which possesses continuous oil column over 800m and the highly heterogeneity of lithology. phisical pro-perty and oil saturation, two equations confining the extend of capillary effectare derived ftom Berg's capillary pressure limit equation and the data of thisoil pool: equation superiores is Zo 1=2.25(10/rt-2) and equation of inferiores limit is Zo 2=0.96(10/rt-2). Double logarithmic graph indicating the relation-chip between the height of oil column and the radius of throat are given by theequation. The inferiores limit of throat radius in seal rock and that of effective porosity are determined as 0.01μm and 0.025μm respectively. Based on the conception of pore group, capillary pressure data of mercury-injection, and k,ω and λ from the analysis of well test data, four types of reservoirs, i.e. the good (1), mediocre (2), poor (3), and non (4). are quantitativelyclassified and evaluated. These results indicate that the depth of oil-water boundary in production in type 1 mainly comprising dissolved pore group is 200 m lower than that in type 3 which has large amounts of fine micropore groups (the everage depth of oil-water boundary in the pool is about 3000m ) .Finally, the authors suggest that, the conglomerate of the P2u1+2 subformation in the Lower Wuerhe Formation is the covering strata, the dispersed lens as partition beds within the reservoir may not stop hydrocarbon from migrating. Though there are plenty of fracturer in conglomerate near the huge Karamay-Wuerhe fault, but all of these fractures are completely filled up to become a non-reservoir or a side-sealed reservoir.

    THE GENESIS AND PREDICTION OF H2S IN NATURAL GAS
    Wang Xinzhou, Li Li, Liu Shouyi
    1987, 8(1):  67-76.  doi:10.11743/ogg19870109
    Asbtract ( 555 )   PDF (9139KB) ( 415 )  
    Related Articles | Metrics

    H2S in natural gas can be produced by biochemical process, thermochemicalprocess or magmatism. The decomposition of sulphur-bearing organic matter andthe reduction of sulfate in higher temperature are the main geneses of H2S. Si-mulating test made by the authors indicates that sulfate can produce H2S inhigher temperature. Some evidences found in rock samples show that carbonateand pyrite replaced anhydrite and formed H2S. It is predicted that natural gasat the depth of 3600-6600m in the Jiyang Depression has the highest contentor H2S.

    THE FORMATION CONDITION AND ACCUMULATION REGULARITY OF OIL AND GAS POOLS IN THE WEST SLOPE OF LIAOHE DEPRESSION
    Zhang Wenzhao
    1987, 8(1):  77-85.  doi:10.11743/ogg19870110
    Asbtract ( 525 )   PDF (7990KB) ( 375 )  
    Related Articles | Metrics

    The exploration practice of the west slope of the Liaohe Depression has veri-fied that a larg area of hydrocarbon enrichment can be formed on the slopebelt. There are several big oil and gas pools such as rolling anticline, buriedhill, turbidite sandbody, thickened oil zone, overlap belt and fault blocks overthere. There are four favourable conditions for hydrocarbon accumulation: a.The slope that depressed first and then declined is rich in oil source andfull filled. b.Multi-source and multi-stage huge sandbody associated with uplift isfavourable for hydrocarbon accumulation. c.The formation of oil and gas pools is contrlled by two kinds of normalfaults that are parallel to the slope. d.The extensively regional caprocks serve as a good preservation to oil andgas pools on the slope.

    THE FORMATION ENVIRONMENT OF RADIOLARIAN SILICILITHS IN THE LOWER PERMIAN IN JIANGSU-ANHUI REGION
    Kong Qingyu, Gong Yujin
    1987, 8(1):  86-89.  doi:10.11743/ogg19870111
    Asbtract ( 625 )   PDF (3575KB) ( 543 )  
    Related Articles | Metrics

    The radiolarian siliciliths of the Lower Permian Gufeng Formation inJiangsu-Anhui Region are composed of well-preserved radiolarian and siliceoussponge bodies. Radiolarians are mainly Flustrella and Lithapium, the contentis generally more than 60%, and in some places even up to 80%. The alternationof the mudstone, shale and pyroclastic rock associated with radiolarian silici-liths are characterized by containing plenty of ferromanganese concretion, lackingshallow-water organisms and devoid of carbonate. This is similar with presentdeepsea sediments. According to paleomagnetic analysis, this region used to be nearthe equator during the Early Permian, and this condition fits in the distributionof deep-sea radiolarian ooze in present equator. All these said above show thatthe s?liciliths were formed in deepsea and distributed in deep trough resultedfrom rift faulting.

    CHARACTERISTICS OF TECTONIC-SEDIMENTARY FACIES IN THE LOWER TERTIARY OF JIZHONG DEPRESSION
    Tian Chonglu, Li Detong, Liu Tiequan, Jiang Hongtao, Wu Zhengming, Lu Songnian
    1987, 8(1):  90-98.  doi:10.11743/ogg19870112
    Asbtract ( 582 )   PDF (9185KB) ( 382 )  
    Related Articles | Metrics

    Deposition is usually controlled by tectonic movements. The so-called tectonic-sedimentary facies is the sedimental facies that are controlled by various tectonic factors in different tectanic units and evolution stages. In the Jizhong Depression, the factors controlling the deposition include followings: 1. differential vertical movements and their strengths; 2. paleotopography is controlled by synsedimentary structures; 3. paleotopography is controlled by gravitational tectonic, and 4. lake level undulation resulted from the tectonic events. The tectonic unites of the Jizhong Depression are very clear in stripped distribution. As the basement uplifted gradually from west to east, the depo-center moved correspondingly. Accorrding to its characteristics, the depression might be divided into three tectonic belts, i.e. a stable subsident belt; an alternated belt of elevation and subsidence and the last one that subsided first and then uplifted. Correspondingly, there are three tectonic-sedimentary facies, i.e.,1. stable subsidence lake facies; 2. alternating fluvial-lake facies: and 3. flu-vial facies with first subsiding, soon elevating. On the tectonic unit of depression, there are six types of the tectonic-sedimentary facies: 1.shore-shallow lake facies of lake-depression; 2. deep-hemideep lake facies of lake-depression; 3. submarine fan of steep slopes or/and faulted scarps; 4. gravitative slumping along the steep faults; 5. subequeous fan on gentle slope; 6. delta facies on gentle slope. According to the structure of paleo-1ake basin, the depression might be divided into enclosed fault depression: semi-enclosed fault depression and nonenclosed fault depression. They correspond to three tectonic-sedimentary facies in the Jizhong Depression as stated above. The first two are favourable for hydrocarbon accumulation, but the last one is not.

    THE SURVEY OF PETROLEUM GEOLOGY AND THE CONTROLLING FACTOR FOR HYDROCARBON DISTRIBUTION IN THE EAST PART OF THE JUNGGAR BASIN
    Li Xibin, Jiang Jianheng
    1987, 8(1):  99-107.  doi:10.11743/ogg19870113
    Asbtract ( 617 )   PDF (7449KB) ( 414 )  
    Related Articles | Metrics

    Good results were obtained in exploration in the east part of the JunggarBasin in recent years, and a new oilfield-Huoshaoshan Oilfield and three struc-tures with commercial oil flow were discovered. The basement of the present area is Middle Carboniferous pyrogenic rocks,and the covering strata has undergone several tectonic moyements. The source stage was mainly in the Hercynian, then the Indosinian and Yanshan; the accumulation and destruction of oil and gas was in Yanshan movement. In the north margin of the Karameili piedmont. the dovelopment of theself-generating and self-reservoiring sequence of the Permian Pingdiquan Formation has controlled the distribution of the oil and gas in this area, that is to say, all those places where the sediments are thick and were not denuded in the late stage are possible zones for hydrocarbon distribution, and all the temperate-amplituded uplifts, fault-blocks and nozes within the zones are favourable structures for hydrocarbon prospecting. In the south margin of the basin,the slope sides of the mid-amplituded uplifts, fault-uplifts and bald-headed structures near the oil generation depression are favourable places for hydrocarbon distribution. Faults in the east part of the basin controlled oil and gas distribution in several aspects.

    CHEMO-HYDROLOGICAL EXPLORATION FOR PETROLEUM IN THE DONGMING DEPRESSION
    Zhang Jinlai
    1987, 8(1):  108-113.  doi:10.11743/ogg19870114
    Asbtract ( 674 )   PDF (4360KB) ( 709 )  
    Related Articles | Metrics

    According to the mineralization intensity, the abundances of hexavalenturanium, dissolved hydrocarbon and phenol of 188 underground water samples,11 anomaly areas are discovered in the Dongming Depression of the HuabeiBasin, and commercial oil flows have been found in three of these areas.

    6TH QUANTITATIVE STRATIGRAPHY SHORTCOURSE
    1987, 8(1):  115-116.  doi:10.11743/ogg19870116
    Asbtract ( 494 )   PDF (2050KB) ( 1152 )  
    Related Articles | Metrics

    During the last decade mathematical treatment of stratigraphic date has becomeincreasingly important.