2007 Vol. 29, No. 1

Display Method:
GAS GENERATION CHARACTER OF DISSIPATED SOLUBLE ORGANIC MATTER
Liu Wenhui, Zhang Jianyong, Fan Ming, Gao Bo, Zhang Dianwei, Zheng Lunju
2007, 29(1): 1-6. doi: 10.11781/sysydz200701001
Abstract(1058) PDF-CN(483)
Abstract:
The generation of natural gas has the character of owning various geological origins.In this paper,the defining process of dissipated soluble organic matter is summarized,the occurrence conditions and generation approaches are analyzed and the effective abundance lower limit is pointed out.It is believed that the dissipated soluble organic matter is the main gas source during the stage of high evolution degree and has broad exploration prospect.It was pointed out that the light hydrocarbon in cracked gas generated from dissipated soluble organic matter has much naphthenic hydrocarbon but it from accumulated soluble organic matter has no naphthenic hydrocarbon and has more paraffin hydrocarbon than benzene and naphthalene series.It was also attested that not only silicate rocks but also carbonate rocks have catalysis for the soluble organic matter generating gas,so the dissipated soluble organic matter is more potential than accumulated soluble organic matter to generate gas.Based on geology reality,the assessment method for dissipated soluble organic matter is indicated to make it operable to evaluate the potential of generating gas.
ZONED-DISTRIBUTION OF OIL AND GAS ACCUMULATION IN FAULT DEPRESSIONS IN THE SONGLIAO BASIN
Gao Shuxin, Ren Huaiqiang, Yang Shaochun
2007, 29(1): 7-12. doi: 10.11781/sysydz200701007
Abstract:
The First,Third and Fourth Members of the Shahejie Formation in the Bonan,Gu'nan and Fulin Subsags are the main source rocks of the reservoir in the northern slope of the Eastern Chenjiazhuang Uplift, the Jiyang Depression,the Bohai Bay Basin.By the analysis of source rock characteristics and oil-source rock correlation,the oil of the Ken68 and Ken69 wells are mainly from the Third Member of the Shanhejie Formation in the Bonan Subsag.The faults,sandbodies,unconformable surfaces and complex channels made up of faults,sandbodies,unconformable surfaces are the main migration pathways for oil and gas.
NEW BRIEF REMARKS ON HYDROCARBON PROSPECTING OF MARINE STRATA IN THE MIDDLE AND UPPER YANGTZE REGION
Chen Hongde, Pang Lin, Ni Xinfeng, Hao Yi
2007, 29(1): 13-18. doi: 10.11781/sysydz200701013
Abstract:
With the development of research and exploration,the dominance of marine oil and gas exploration is overhanging in Middle and Upper Yangtze region.Based on establishment of regional sequence stratigraphic framework,it is pointed out that the regional main source rocks are Z2ds(SS1-TST),lower-C1(SS3-TST),O3w and lower S1(SS7-LST,TST),P2q(SS12-TST),P3(SS13-TST),expect that Wufeng Formation(O3w) formed in SS7-LST,others formed in the transgressive system tract of the supersequence.While the high-quality regional reservoirs would be consistent with the highstand of the supersequence,they are Z2d(SS2-HST),-C2,-C3(SS4-HST),C2(SS11-HST),P2m(SS12-HST),P3ch-T1,T2(SS13-TST,HST).The distribution of the regional cap rocks are the same as the regional main source rocks,however,their types are more abundant,and they formed at the same time of second-order sea-level rising quickly.Finally,it is suggested that reef flat limestone-dolomitized limestone/dolomite-palaeokart are the most favorable reservoirs,paleohigh+late structural-lithologic strata traps are the most favorable location,and northeastern Sichuan-western Hubei area(two platform margins and one platform) and southeastern Sichuan-Middle Guizhou-western Hubei area(one platform margin and one platform) are the priority area,southeastern Sichuan-northern Guizhou and western Hubei-eastern Chongqing are the frontier where exploration breakthrough would be expected in the near future.
NATURAL GAS MODELS CONTROLLED BY GRADED MULTI-FACTORS IN MARINE SEQUENCES OF SOUTH CHINA
Xu Sihuang, Ma Yongsheng, Mei Lianfu, Yuan Caiping, Guo Tonglou
2007, 29(1): 19-24. doi: 10.11781/sysydz200701019
Abstract:
Having multiple stages of tectonic events,most of marine petroleum reservoirs in South China belong to secondary petroleum reservoirs.The reformation and distribution of petroleum reservoirs were mainly controlled by graded pool-controlling factors.The first grade of pool-controlling factors were the pool fluid sources,the second grade were the periods of petroleum formation and reconstruction,and the third included preservation condition and trap types.Ten types of pool-controlling models were set up based on the first two grades of pool-controlling factors in South China.Four of them,including primary source primary accumulation,secondly source primary accumulation, inorganic source primary accumulation and mixed source secondary accumulation,have been confirmed by exploration,named as type Well Mian 31,type Zhujiadun,type Huangqiao,and type Sichuan by known cases.The distribution map of eight typical pools models based on first three grades of pool-controlling factors supports that type Sichuan distribute mainly in Upper Yangtze Block,type Well Mian 31 mainly in margin of Jiannan Uplift,type Zhujiadun in Middle and Lower Yangtze Block,and type Huangqiao mainly in tensional structural area.
BASIN SEQUENCE AND OIL-GAS POTENTIAL IN NEAR NORTHERN QINLING-DABIE MOUNTAIN
Huang Zeguang, Gao Changlin
2007, 29(1): 25-31. doi: 10.11781/sysydz200701025
Abstract:
There are lots of basins which have contained some oil gas in near northern Qinling-Dabie mountain.The geological-geochemical research results showed that there are 6 basin generations in near northern QinlingDabie mountain: 1)passive continental margin basin(C1-O2),2)back-arc basin(O2-C1),3)residual basin(C2-T2),the stage 1(C2-P12) and stage 2(P12-T2),4)intracontinental foreland basin(T3-J2),5)extensional strike-slip basin(J3-K1),6)fault-depression basin(K2-E).Six source rock suites have been developed,Eogene system,Lower Cretaceous,Lower Jurassic,Upper Triassic,Carboniferous-Permian and Lower Palaeozoic in near northern Qinling-Dabie mountain.The main prospecting strata are Carboniferous-Permian,Lower Cretaceous,Upper Triassic and Eogene system in near northern Qinling-Dabie mountain.The Zhoukou Basin,Jiyuan Basin and Lao-Yi Basin are chosen as prospect.The Tanzhuang-Shenqiu Sag,Niqiuji Sag,Xiangcheng Sag,Wuyang Sag,Mengxian-Wenxian Sag and Luoyang Sag are chosen as favourite district.
THE ANALYSIS OF FORMATION MODELS OF LITHOLOGICAL RESERVOIRS ON THREE KINDS OF TYPICAL STRUCTURAL ZONES IN THE ERLIAN BASIN
Liu Zhen, Fu Dongyang, Xiao Wei, Du Jinhu, Yi Shiwei, Dang Huqiang
2007, 29(1): 32-39. doi: 10.11781/sysydz200701032
Abstract:
The sags in Erlian Basin can be divided into three kinds of typical structural zones: steep slope,gentle slope and depression zone.These structural zones have different combination models of accumulation conditions.And the three models of accumulation conditions respectively are: the combination model of accumulation conditions on steep slope,the compounding model of accumulation conditions on genule slope and the combination model of accumulation conditions on depression zone.In addition,different structural zones have different formation models of the lithological reservoirs.They can be summed up as follows: 1) the oil's generating and preserving in same formation on steep slope,2) the oil's generating in a formation and preserving in sideward layer on gentle slope,3)the oil's generating in lower formation and preserving in upper one on depression zone.The three typical models of oil accumulation are the breakthrough of the exploration of the lithological reservoirs in the Erlian Basin at present.
GENETIC TYPES AND DISTRIBUTION FORECAST OF AVAILABLE CARBONATE RESERVOIRS IN ORDOVICIAN IN THE CENTRAL AREA OF TARIM BASIN
Zhao Zongju, Wang Zhaoming, Wu Xingning, Chen Xueshi
2007, 29(1): 40-46. doi: 10.11781/sysydz200701040
Abstract:
The available reservoirs of Ordovician carbonate in central Tarim can be classified into 3 types as epidiagenetic paleo-karst reservoir,burial karst reservoir and interlayer dolomite reservoir,and the epidiagenetic paleo-karst reservoir can be subdivided into 2 types as epidiagenetic karst reservoir formed later than Ordovician(EKR-1) and epidiagenetic karst reservoir formed from late Middle Ordovician to early Late Ordovician(Llandeilo to early Caradoc)(EKR-2).The key controlling factors to EKR-1 are paleo-karst morphology from Silurian to Devonian especially in Devonian and silicification by magma heat liquids in Permian.The favorable exploration regions are mainly distributed in areas from Tazhong-19 to Tazhong-9,Tazhong-1 to Tazhong-4 to Tazhong-403 and Tazhong-16 to Tazhong-15.The chief controlling factors to EKR-2 recently-discovered should be paleo-karst morphology from Llandeilo to early Caradoc and fault karstification of several stages.The reservoir is chiefly distributed in the middle-upper part of the Yinshan Fm.of the Lower Ordovician and in the area from the Tazhong Uplift to the Bachu Uplift.The burial karst reservoir mainly distributed in the Lianglitage Fm.of the Upper Ordovician is chiefly controlled by sedimentary facies(carbonate shoal) and the meteoric water dissolution produced from penecontemporaneous exposure,burial(organic or inorganic) karstification and fault-channeled fresh-water karstification.The available reservoir is chiefly distributed in shelf marginal high-energy shoal and reef of the Lianglitage Fm.developed in the southern belt near Tazhong-I Fault,forming a giant primary stratigraphy oil-gas pool traped by diagenetic carbonate heterogenetic karst reservoir.The key controlling factors to interlayer dolomite reservoir in the Lower Ordovician should be sedimentary facies(semi-restricted to restricted platform),burial recrystallization,burial karstification and fault-channeled fresh-water karstification.The reservoir is generally distributed by layers of larger area,and in the whole Tazhong-Bachu Uplift even in other more extensive regions,with small types of pore and cavity.
TYPES AND STRUCTURAL CHARACTERISTICS OF BRINK SAGS IN FAULTED BASIN
Zhang Shulin, Fei Qi, Ye Jiaren
2007, 29(1): 47-51. doi: 10.11781/sysydz200701047
Abstract:
The faulted structural strata are usually constituted by numerous fault-blocks in faulted basin.In the extending process,each faultblock is a comparatively independent sedimentary and subsidence center.In the process of rift-subsidence evolvement,some fault-blocks succession rift and subside for a long period,becoming the host sags of the primary oil source center,and the others show the less range of subsidence or strong denudation,becoming the brink sags,all these just because of the difference in structure position,boundary fault strike,and dynamics characteristics.According to the formation and the function in structural activity,the brink sags can be divided into abandoned-type,adjusted-type,transitional-type,and reconstructed-type.
FACIES STUDY OF THE NEOGENE UPPER GUANTAO FORMATION IN THE CHENGDAO OILFIELD, THE BOHAI BAY BASIN
Zhang Haina
2007, 29(1): 52-56. doi: 10.11781/sysydz200701052
Abstract:
The Chengdao Oil Field is the first shallow oil field put into development in China.Applying sedimentary petrography and geology,the sedimentary petrographical and structural characteristics,logging curves and palaeontologic features of the Neogene upper Guantao formation(Ng) have been studied on the basis of geological setting,core description and logging analysis.Sands of the upper Ng belong to fluvial facies and the subfacies is meandering river by many identification parameters of river types.Then,4 types of microfacies have been concluded,the palaeocurrent directions of the main unit have been pointed out,and the deve-lopment characteristics and effects of different microfacies have been evaluated.
CHARACTERISTICS OF THE HEFEI JURASSIC BASIN AND ITS SEDIMENTARY RESPONSE TO THE DABIESHAN OROGENIC BELT
Wang Yalin, Yang Guili, Xu Chunhua
2007, 29(1): 57-62. doi: 10.11781/sysydz200701057
Abstract:
Characteristics of the Hefei Jurassic Basin and the Dabieshan Orogenic Belt have been studied from the aspect of basin-and-range coupling in this paper.With the second uplifting of the Dabieshan Mountain,the northern fringe of the Dabieshan Mountain underwent the strongest subsidence and sedimentation in the early Jurassic and then the Hefei Jurassic Foreland Basin was formed.Afterwards,the subsidence-sedimentation process slowed down gradually in the south of the Hefei Basin in the Middle-Late Jurassic without any strengthening phenomenon.The authors also briefly introduce the sediment characteristics of the Jurassic Formation in different areas of the Hefei Basin.On this basis,the sedimentary response to the Dabieshan Orogenic Belt of the Hefei Jurassic Basin is studied thoroughly from the aspects of basin structure,clastic matrix constituents of sediments,sequence architecture and sedimentary system,and so on.The study demonstrates that these two things are coupling very well.
GENETIC RESEARCH OF RESERVOIRS AT DELTA FRONT IN DEPRESSED LACUSTRINE BASINS
Li Fengjie, Wang Duoyun, Wang Feng, Zhao Junxing
2007, 29(1): 63-68. doi: 10.11781/sysydz200701063
Abstract:
During the Late Triassic,the Ordos Basin is an asymmetry depressed lacustrine basin with gentle slope in the east and steep slope in the west.In the Yanchang Formation,oil is mainly distributed at the gentle slope in the east.With the short-term base-level cycle theory of high-resolution sequence stratigraphy,it is analized in this paper the reservoir sandstones deposited at delta front in the Chang VI oil formation in Jiyuan and Anbian,the Ordos Basin.According to genetic difference,reservoir sandstones may be divided into three types and seven subtypes,evidently influenced by the short-term base-level up and down changes and the relation between accommodations and sediment alimentations.As the base-level goes up and down,regular changes of short-term base-level cycle affect the distribution of different genetic sandstone bodies.And the distribution model of different genetic sandstones deposited at delta front in depressed lacustrine basins is built.The delta front in this area can be divided into three parts: platform delta front,sloping delta front and basin delta front by the bounds of slope break.Reservoir sandstones are genetically different at different parts. Truncated and integrated channel sandstone bodies are found at platform delta front.Downside deformity recombination bar sandstone bodies are found at sloping delta front.Integral recombination bar,upside deformity recombination bar,isolated mouth bar and reiterative mouth bar sandstone bodies are found at basin delta front.The compartment scheme of delta front and the discription of reservoir bodies can be helpful for high quality reservoir identification and prediction,and it can also serve to subdivide flow units during oil exploitation.
OIL-SOURCE CORRELATION AND RESERVOIR ANALYSIS IN THE NORTHERN SLOPE OF THE EASTERN CHENJIAZHUANG UPLIFT, THE JIYANG DEPRESSOIN, THE BOHAI BAY BASIN
Zhou Liqing, Wu Yuyuan, Zhang Huai
2007, 29(1): 69-73. doi: 10.11781/sysydz200701069
Abstract:
Controlled by the NNE oriented deep fault rupture,three Late Jurassic-Early Cretaceous fault subsidence zones were developed in the east,middle and west of the Songliao Basin.Evident differences among structure depositional evolutions of these three zones cause distinct zoned-distribution of oil and gas accumulation in this area.In heritage deep sags developed along the Sunwu-Shuangliao deep fault in the central part,large thick lacustrine facies source rocks and volcanic rocks as well as sandstones and grits were developed.The fault sags are overlaid with multiple giant thick lacustrine facies mudstones,providing favorable conditions for oil and gas containing,as well as for continuing thermal evolution.Therefore,a number of middle and large scaled oil and gas fields were developed on the nearly EW strike heritage nose-like dome belt in low uplifts and slope break zones.While in the east and west margin,only small and middle scaled oil and gas fields were developed,due to the small volume of hydrocarbon rocks with lower quality mother matter,low source rock abundance and poor containing condition.
THE APPLICATION OF N-ALKANE'S ODD-EVEN CARBON NUMBER PREDOMINANCE IN OIL-SOURCE ROCK CORRELATION——AN EXAMPLE OF THE LOWER PALEOZOIC IN TARIM BASIN
Luo Xianying, Zhao Zongju, Meng Yuanlin
2007, 29(1): 74-77. doi: 10.11781/sysydz200701074
Abstract:
The composition and distribution of the carbon number of n-alkane can reflect the source of organic matters,sedimentary environment and maturity of organic matter.Comparision of the n-alkane's GC diagrams in Tazhong Low Uplift shows that odd-carbon predominance appears in the Upper Ordovician source rocks,and even-carbon predominance has taken on in Cambrian-Lower Ordovician source rocks.The result of oil-source rock correlation shows that the origin of oils in the fields of Well TZ 10-11-12 is the Upper Ordovician source rocks,and the oils of Well TZ 45 and Well TZ 162 are from CambrianLower Ordovician source rocks.And the strata corresponding to the crude oils with odd-even carbon number predominance is accorded with what the oil-source rock correlation shows.In a word,the characteristics of n-alkane's odd-even carbon number predominance can be as an effective method for oil-source rock correlation in Tazhong Low Uplift,Tarim Basin.
DISTRIBUTION AND MIGRATION FEATURES OF H2S IN THE TRIASSIC IN THE NORTHWESTERN SICHUAN
Xu Hao, Tang Dazhen, Wei Guoqi, Zhang Junfeng
2007, 29(1): 78-81. doi: 10.11781/sysydz200701078
Abstract:
Based on the deep researches of diagenesis in the northwestern Sichuan,chemical composition of the fluid inclusions in different formations and different attitudes were analysed by Laser Roman Microspectrometer.And the distribution characteristics of H2S and its migration features were discussed.The results show that the charging of hydrocarbon with high H2S concentration from low formation last a long time.Hydrocarbon being charged at the stage of diagenesis of the 2nd Member of Xujiahe Formation has a high H2S concentration and its migration pathway are mainly the hole,throat and fissure system,while hydrocarbon being charged at the later stage has a relatively low H2S content and its migration pathway is mainly the fissure system.And sustained reducing environment is necessary for H2S not being exhausted during migration.
GEOCHEMICAL CHARACTERISTICS OF THE CRETACEOUS OIL AND CORRELATION OF OIL TO SOURCE ROCK IN WUERXUN AND BEIER DEPRESSIONS,THE HAILAER BASIN
Jie Yixin, Yuan Yueqin, Wang Bin
2007, 29(1): 82-87. doi: 10.11781/sysydz2007010082
Abstract:
Based on the GC,GC-MS and nonhydrocarbon nitric chemical compound analytical data of 21 samples of crude oil and hydrocarbon-bearing rocks,the geochemical characteristics of the Cretaceous oil in Wuerxun and Beier depressions in Hailaer Basin were studied,and the main source rock for the oil was determined by oil-source rock correlation.The studied results reveal that there are two kinds of crude oil in Wuerxun and Beier depressions.One kind shows a dominance of n-alkanes in C17-C23 and distribution in unimodality.Its Pr/Ph is higher than 1(1~2.88).The"V"shaped distribution of C27-C29 steranes and low gammacerane indicate a fresh water lacustrine source rock.The other one shows a dominance of n-alkanes in light hydrocarbons and low C27 sterane.Its Pr/Ph is less than 1 and it lacks gammacerane.This kind of oil mostly stemmed from the coal measure strata.According to the results of oil-source rock correlation,the crude oils in Wuerxun and Beier depressions stemmed from two kinds of depositional setting.It indicates that there are good conditions of source rock in Hailaer Basin.
COMPARISONS OF GEOCHEMICAL METHODS FOR ASSESSMENT OF HYDROCARBON-GENERATING POTENTIAL
Liu Quanyou, Liu Wenhui, Wang Xiaofeng, Wang Wanchun
2007, 29(1): 88-94. doi: 10.11781/sysydz200701088
Abstract(1045) PDF-CN(348)
Abstract:
In this context,on the basis of comparison of three geochemical methods for assessment of source rocks,Rock-Eval pyrolysis,H/C ratio and hydrous pyrolysis,the hydrocarbon-generating potential of the low-mature coal in the Manjiaer sag,Tarim Basin,was determined.The compared results show that the potential of hydrocarbon-generating obtained by H/C ratio is similar with that by hydrous pyrolysis.The yields of hydrocarbon-generation based on the methods of H/C ratio and hydrous pyrolysis are 9.62 and 9.72 mg/g,respectively.In contrast,the yield of hydrocarbon formation is 32.75 mg/g by using method of Rock-Eval pyrolysis,higher than those obtained by the other two methods.It is provided the maximum yield of hydrocarbon generation for Rock-Eval pyrolysis,whereas the effective expelling of hydrocarbons will be obtained by H/C ratios and hydrous pyrolysis.Therefore,it would be necessary for hydrocarbon source assessment to use the geochemical method based on the special regions and aims.
LITHOLOGIC OIL POOL EXPLORATION METHOD——A CASE STUDY OF THE LIAOHE DEPRESSION IN THE BOHAI BAY BASIN
Yang Fei, Zhang Hongyan, Cheng Junsheng
2007, 29(1): 95-98. doi: 10.11781/sysydz200701095
Abstract:
MQZ region is situated in the western sag of the Liaohe Depression in the Bohai Bay Basin.The ramp zone controlled by slope break is favorable for underwater fans generation.Since they are near source rock and have good reservoir beds and channels,the low-system-type fans can form lithologic oil pools.By exploring lithologic traps in MQZ area,it is concluded in this paper the 3 ways to explore lithologic traps.High resolution seismic data are the base of lithologic trap exploration,sequences stratigraphy is the theory, and seismic prediction technology is the method.
STUDY ON THE SIMULATED BIODEGRADATIED STERANE IN CRUDE OIL
Zhang Qu, Song Xiaoying, Zhang Zhirong
2007, 29(1): 99-102. doi: 10.11781/sysydz200701099
Abstract:
The biodegradation of regular sterane and rearranged sterane in crude oil was studied on the basis of simulated biodegradation experiment to the crude oil.The biodegradation products were analyzed by GC-MS.Research shows that the biodegradation of regular sterane is early than that of rearranged sterane.The biodegradation ability of sterane is C27>C28>C29.Before the great biodegradation of the sterane,those maturity indicators such as isomerization of C29 steranes at C20 vary slightly.But some biomarker indicators used for the researches on oil-source correlation,oil source and sedimental environment will probably change.These indicators include ratio of regular steran to 17α(H)-hopane,C27-C28-C29 sterane,C27-C28-C29 rearranged sterane,ratio of rearranged sterane to regular sterane,and so on.
THE ON-LINE ANALYTICAL TECHNOLOGY OF LIGHT HYDROCARBON IN GAS SOURCE ROCK THERMAL SIMULATION RESOLVING PRODUCTS
Xu Xingyou, Li Zheng, Wang Yurong, Li Juyuan, Tang Hongsan, Lin Wu
2007, 29(1): 103-107. doi: 10.11781/sysydz200701103
Abstract:
Making use of the on-line analytical technology,the light hydrocarbons in high mature hydrocarbon source rock thermal simulation resolving products were analyzed.The result shows that the amount of generated light hydrocarbon increases with the simulation temperature rises.For the samples with high maturity,the parameters of mature degree of the light hydrocarbons have little change.Parameters indicating organic matter type have regular changes within the original scope of judge.But the benzene index can't be used as a judge parameter of organic matter type for high mature hydrocarbon source rock.By applying increasing the thermal simulation temperature to obtaining the composition characteristics of C6-C7 light hydrocarbons,the reliable parameters of organic matter type,maturity and oil/gas-source correlation of high-over mature source rock can be offered.
EXPERIMENTAL STUDY ON PERMEABILITY VARIATION WITH CONFINING PRESSURE IN MICRO-FRACTURE AND LOW-PERMEABILITY ROCK
Xue Yongchao, Cheng Linsong
2007, 29(1): 108-110. doi: 10.11781/sysydz200701108
Abstract(1036) PDF-CN(362)
Abstract:
The development of the reservoir with low-permeability is becoming increasingly important.But its strong diagenesis,fine and close lithology and general development of micro-fractures make permeability, the key symptomatical parameter,has strong stress sensitivity.In order to get the quantitative relation between permeability and confined pressure in microfracture and low-permeability rocks,a theoretical relation was attained based on theoretical research and some hypothesis.With this guidance,an experimental study was carried out on three low-permeability cores with natural micro-fracture from an oil field.Through analyzing the experimental data and matching work,a relation curve was acquired from the experiment by which we can get the undetermined coefficient of the theoretical relation and finally obtain the quantitative relation between permeability and confined pressure in the micro-fracture and low-permeability rocks.