2011 Vol. 33, No. 5

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2011, 33(5)
Abstract(1056) PDF-CN(816)
Abstract:
New progress in basic studies of hydrocarbon generation and expulsion of source rock in finite space
Guan Defan, Xu Xuhui, Li Zhiming, Zheng Lunju, Ma Zhongliang
2011, 33(5): 441-446. doi: 10.11781/sysydz201105441
Abstract(2944) PDF-CN(1032)
Abstract:
Simulation of hydrocarbon generation and expulsion of source rock in finite space has been carried out with the hydrocarbon generation and expulsion simulation experimental instrument of type DK-Ⅱ with porosity,temperature and pressure under geological conditions.It has been concluded that the process of hydrocarbon generation of source rock during basin subsidence can be divided into 3 stages as follows.1)Ro≤0.70%,oil generates from source rock slowly;2)0.70% Ro 0.90%,oil generates rapidly,and reaches the peak when Ro is 0.90%;3)Ro 0.90%,oil gene-ration from kerogen has finished due to the fluid pressure in source rock.And during the 3rd stage,the oil expulsed from source rock cracking stays on rock surface and in connected microfractures.Part of the expulsed oil migrates into sandstones which interbed with source rocks.When the maturity of source rock is over 0.70% and the pressure differential between source rock and reservoir during basin uplifting reaches about 4-5 MPa,oil migrates far away and accumulates.
Simulation of source rock for hydrocarbon generation and expulsion in finite space and its significance
Li Zhiming, Zheng Lunju, Ma Zhongliang, Xu Ershe, Yu Xiaolu, Jin Guangxing, Mu Xiaoshui
2011, 33(5): 447-451. doi: 10.11781/sysydz201105447
Abstract(3581) PDF-CN(969)
Abstract:
Simulation of source rock for hydrocarbon generation and expulsion in finite space has been carried out with samples from the Es23 sub-section of the Dongpu sag using the hydrocarbon generation and expulsion simulation experimental instrument of type DK-Ⅱ with porosity,temperature and pressure under geological conditions.It has been concluded that the process of hydrocarbon generation and expulsion of source rock can be divided into 4 stages as follows.1)Ro≤0.72%,oil generates slowly and does not expel;2)0.72% Ro 0.80%,oil generates rapidly,but still remains in source rock;3)0.80% Ro 1.00%,oil generation from kerogen has finished or suppressed,and oil transfers from big molecular to small molecular.Oil migrates to and assemblages in the upper and lower adjacent sandstone as well as source rock surface and fracture,which may guide unconventional hydrocarbon exploration in source rock dominant belt in the Dongpu Sag or the other similar basins or sags;4)Ro 1.0%,oil cracks to gas;however,oil does not crack to CH4 completely and mainly remains in oil even though Ro 2.0% or 2.4%.The studies suggest that petroleum exploration can be carried out in deeper formation.
Quantitative evaluation of hydrocarbon yielding potential of source rock: application of pyrolysis in finite space
Zheng Lunju, Ma Zhongliang, Wang Qiang, Li Zhiming
2011, 33(5): 452-459. doi: 10.11781/sysydz201105452
Abstract(3092) PDF-CN(1016)
Abstract:
With the formation porosity thermocompression simulation experiment instrument designed by Wuxi Research Institute of Petroleum Geology,immature perse mudstones from the 3rd member of Hetaoyuan Formation in the Biyang Sag were pyrolyzed in finite space and with phased,continuous and progressive temperature.The stage and total product rates of oil,gas and total hydrocarbon of type Ⅱ 1 kerogen during different evolution stages were calculated.Comparison was made between the above-mentioned method and the conventional open-system Rock-Eval experiment.A new evaluation method to study hydrocarbon generation potential in finite space was put forward.The following parameters were used to judge the hydrocarbon generation potential of kerogen.1)Residual oil potential and index.2)Oil generation potential and index of kerogen.3)Gas generation potential and index of kerogen.4)Total hydrocarbon generation potential and index of kerogen.5)Maximum temperatures for oil,gas and total hydrocarbon generation and reflectance.Quantitative evaluation of oil,gas and total hydrocarbon generation potential of kerogen during certain stage was made,and the generation process was described using the parameters.
Calculation of denudation amount with Milankovitch cycle method: a case study in Biyang Sag
Yao Yimin, Xu Xuhui, Liu Cuirong, Tan Caiping, Luo Jiaqun, Zhu Jingxiu
2011, 33(5): 460-467. doi: 10.11781/sysydz201105460
Abstract(1842) PDF-CN(855)
Abstract:
The denudation thickness of Paleogene—Neogene unconformity in the Biyang Sag has been calculated with the Milankovitch cycle method.The calculation process has been divided into 2 steps.1)Put the strata classification and logging curves of all formations as well as sections and sub-sections into "studies system of cyclostratigraphy"(version 1.0) so as to find the 0.405 Ma period.In this way,the maximum dominant cycle and the sedimentary time for available strata can be calculated.2)Transform the denudation time besides of the above-mentioned sedimentary time for available strata into erosion thickness according to the 0.405 Ma period.It has been concluded that in the center of the sag,only Liaozhuang Formation is denuded.In Anpeng area which locates in the southeast of the sag,the denudation thickness is less than 100m and increases gradually to the west,northwest and northern margin of the sag,and finally exceeds 650m around the missing boundary of Liaozhuang Formation.Hetaoyuan Formation is also denuded near to the sag boundary,mainly 4.1-666.5 m thick,and the total denudation thickness is over 1000m.The known Oil fields in the sag mainly locate in the area with denudation thickness larger than 200m.
Application of quantitative examination of petroleum generation and accumulation in Biyang Sag, Nanxiang Basin
Tan Caiping, Chen Yongfeng, Jiang Xingge, Luo Jiaqun, Zhu Jingxiu, Cheng Jian, Wang Yifang, Fan Yunhe
2011, 33(5): 468-473. doi: 10.11781/sysydz201105468
Abstract(3055) PDF-CN(929)
Abstract:
Petroleum was reserved in pores of source rocks(usually mudstones) after generation.The pore volume of source rock controlled the total amount of hydrocarbon generation.When petroleum had moved out from source rock,the pore volume of source rock decreased due to the compaction of overlying strata,and the decrease amount was equal to the petroleum expelling amount.In this way,we can calculate the total pore volume and the decrease amount so as to find out the generation and expelling amounts of petroleum.If the overlying strata were eroded,sandstones would rebound since pressure had changed.Pore increases resulted from sandstone rebounding caused the decrease of formation fluid pressure,providing both driving force and room for petroleum migration and accumulation.Case studies in the Biyang Sag have indicated that,from Hetaoyuan Formation to the end of Liaozhuang Formation,the sag kept subsiding and pressure increased.Petroleum mainly generated during this stage,accounting for over 50%.The regions such as Guian,Shuanghe,Houzhuang and Wangji are main accumulation locations,where sandstone rebounding amount and pressure decrease resulted from erosions during Liaozhuang stage are bigger.
Transporting and sealing capacity of fault belt and its controlling on reservoir
Luo Qun
2011, 33(5): 474-479. doi: 10.11781/sysydz201105474
Abstract(2819) PDF-CN(1017)
Abstract:
According to the inner structure as well as the sealing and transporting capacity of fault belt,it has been concluded that fissures generate well in the upper block of fault belt in petroliferous basin.Well-developed fissures are favorable for petroleum vertical migration and help reservoir form in the upper block.In the lower block of fault belt,fissures do not generate.Horizontal sealing works well and screens petroleum so as to form reservoir.It explains why screened oil pools are widespread in the lower block of antithetic fault and why petroleum leaks in the upper block of consequent fault.
Petroleum accumulation conditions of Damoguaihe Formation in Urxun—Beier Sags, Hailaer Basin
Li zh, ong, Li Yang, Zhang Haixiang, Chen Zhiwei
2011, 33(5): 480-487. doi: 10.11781/sysydz201105480
Abstract(3211) PDF-CN(914)
Abstract:
The petroleum accumulation conditions of Damoguaihe Formation in the Urxun—Beier Sags of the Hailaer Basin were studied with stratigraphic,tectonic and accumulation system theories.The fractures in the study area experienced 3 stages of deformation including the extension during Tongbomiao and Damoguaihe periods,the strike-slip during Yimin period and the strong inversion during Qingyuangang and the late Paleogene periods.Damoguaihe Formation was divided into 3 third-grade sequences and 15 sand layers.Different stages controlled different sedimentary evolution processes.The crude oil in Damoguaihe Formation came from Nantun Formation and was closely related to the first member of Nantun Formation.There existed 2 ways of hydrocarbon migration.1)When the fault displacement was over 300 m,the source rocks in Nantun Formation connected with the reservoirs in Damoguaihe Formation,resulting in side-generating and side-reserving reservoirs.2)The hydrocarbon in Nantun Formation migrated upwards into Damoguaihe Formation,and then moved laterally for a short distance,forming lower-generating and upper-reserving reservoirs.The reservoirs in the region were classified into 4 types: tectonic,lithologic,stratigraphic and lithologic—tectonic.
Features and main controlling factors of carbonate reservoirs in Tahe Oil field and northern Tarim Basin
Ding Yong, Peng Shoutao, Li Huijun
2011, 33(5): 488-494. doi: 10.11781/sysydz201105488
Abstract(3861) PDF-CN(996)
Abstract:
Ordovician reservoirs in the Tahe Oil field are dominated by fracture and vug,and have experienced stages of deformation.They have the same features as those in the northern Tarim Basin.1)Periods of karst effect.Caledonian paleostructure and karst palaeogeomorphology provided pathways for hydrocarbon migration and room for reservoir formation.2)The reservoir and cap combination in Ordovician itself worked as the most important combination for Ordovician reservoir.3)Karst unconformities offered ways for regional migration,and formed migration system together with fractures and fissures.4)Reserve conditions after accumulation controlled the distribution of ancient reservoir.Petroleum accumulated in the late stage mainly enriched in the higher locations.5)Accumulation started in the late Caledonian,and came across stages of filling adjustment.
Formation mechanism of karst reservoir in buried hill, North Jiangsu Basin
Li Yahui, Duan Hongliang, Qiu Xuming, Wang Hongwei
2011, 33(5): 495-498. doi: 10.11781/sysydz201105495
Abstract(3668) PDF-CN(965)
Abstract:
By means of core observation,thin-section identification as well as carbon and oxygen isotope analysis,the reason for the differences of karst reservoir generation between well XG1 and well XC1 in buried hill of Xinghua city of the North Jiangsu Basin has been studied,and the formation mechanism of karst reservoir in buried hill has been concluded.The rock fabric exposed on karst surface and the karst landform during Indosinian and the middle Yanshanian are the main controlling factors for karst reservoir generation in the study area.They also explain the differences of karst reservoir generation between the above-mentioned 2 wells.Strong warping at the end of Sanduo period not only deformed the karst setting on buried hill surface,but also activated underground fluid,which intensified corrosion in well XC1.It was favorable for secondary pore generation,and unfavorable for the preservation of buried hill reservoir.The explorations for buried hill reservoir should be focused on the passive side of border fault of sag,and the saddle between low uplifts of Mesozoic-Cenozoic as well as the Lower Paleozoic crystalline dolomite buried hill below slope.
Characteristics and evaluations of reservoirs in Carboniferous-Permian, Northeast China
Wu Yingli, Zhu Jianhui, Zhang Xinguo
2011, 33(5): 499-504. doi: 10.11781/sysydz201105499
Abstract(3229) PDF-CN(843)
Abstract:
According to field observations and outcrop sample tests,the conditions of Carboniferous-Permian reservoirs in Northeast China have been studied.Carboniferous and Permian strata are widespread in Northeast China.Both marine and continental facies are found and the marine facies changes to the continental facies from Carboniferous to Permian.Limestone and clastic rock are the dominant formation compounds,and in some region,pyroclastic rock accounts for the largest proportion.The reservoir conditions of Carboniferous-Permian are usually poor.As to Carboniferous strata,the type-Ⅰ reservoirs mainly locate in the southwest of Erlian city,and the type-Ⅱ in the northeast of Erlian city and in Panshi city(south of the Songliao Basin),and the type-Ⅲ in Sanjiang county and the north of the Songliao Basin.As to Permian strata,the type-Ⅰ reservoirs distribute in Yichun city(north of the Songliao Basin) and Guandi town of Linxi county of Erlian city,and the type-Ⅱ around West Ujimqin(east of Erlian city) and Yongji county(south of Songliao Basin),and the type-Ⅲ around Zhenlai county of Inner Mongolia.
Petroleum accumulation in Upper Paleozoic, Huangqiao region, Lower Yangtze Basin
Xia Zailian
2011, 33(5): 505-508. doi: 10.11781/sysydz201105505
Abstract(3568) PDF-CN(932)
Abstract:
The tectonic evolution,petroleum accumulation history,accumulation type and main controlling factors in Huangqiao region of the Lower Yangtze Basin were studied with the balanced cross section,fluid inclusion,geochemical and physical analysis methods.The tectonic evolution in Huangqiao region experienced 3 stages including the stable uplift and deposition,the extrusion and nappe,and the extension and rift.2 periods of petroleum filling took place in the region.From the late Yanshanian to Himalayan,petroleum accumulated.During the late Himalayan,the reservoirs in the Upper Paleozoic were saved and finally formed.The reservoirs found in well HT3 belong to Longtan Formation.They were self-generated and self-reserved.Structures controlled petroleum accumulation.Physical properties influenced reservoir distribution.
Petroleum accumulation conditions in Enping Sag, Pearl River Mouth Basin
Yu Kaiping, Zhang Gongcheng, Liang Jianshe, He Shibin, Ding Fang, Tao Zongpu
2011, 33(5): 509-512. doi: 10.11781/sysydz201105509
Abstract(3328) PDF-CN(1059)
Abstract:
The Enping Sag locates in the west of the Zhu Ⅰ Depression.Petroleum has been found in the sag;however,no industrial breakthrough has been made.Source depression controls the horizontal distribution of petroleum in the study area.Petroleum accumulates around depression and near to source.Due to fault activity and the southward uplifting of source formation,the southern gentle slope is the favorable target for petroleum migration.3 sets of reservoir and cap combinations have been found in the region,including the Wenchang Formation,the upper Enping Formation,and the Zhujiang—Hanjiang Formation,which control the vertical distribution of petroleum.Based on the experiences from failed wells,the accumulation conditions in the area have been pointed out and the accumulation model has been established.The Enping Sag is favorable for petroleum accumulation.The shallow layers in the southern gentle slope and the deep layers in the central fault belt are the most potential targets for exploration in the Enping Sag.
Controlling factors of physical property of Upper Paleozoic reservoir, Daniudi Gas Field
Wang Yongjian, Wang Yanbin, Li Xia, Gao Shasha, Guo Hui
2011, 33(5): 513-516. doi: 10.11781/sysydz201105513
Abstract(3742) PDF-CN(916)
Abstract:
The Upper Paleozoic reservoirs in the Daniudi Gas Field are characterized by low porosity and low permeability.The physical property of the 3rd and 2nd members of Lower Shihezi Formation is the best,while that of the 1st member of Shanxi Formation is worse,and that of the 2nd member of Shanxi Formation and the 1st member of Lower Shihezi Formation is the worst.The difference of physical property is influenced by several factors such as sedimentary facies,diagenesis,clay mineral,fissure and so on.Sedimentary facies is the basic factor.Meandering sand body has the best physical property,braided fluvial sand body the second,and delta channel sand body the worst.Diagenesis also plays an important role,especially the compaction effect.From the 1st member of Shanxi Formation to the 3rd member of Lower Shihezi Formation,as the compaction effect decreases,the surplus interparticle porosity of reservoir increases and the physical property is improved.Clay mineral composition,content and fissure also influence physical property.Generally speaking,higher illite content results in worse property,and the generation of microfracture may improve property.
Accumulation and distribution of giant oil and gas fields in Campos Basin, Brazil
He Juan, He Dengfa, Li Shunli
2011, 33(5): 517-525. doi: 10.11781/sysydz201105517
Abstract(3624) PDF-CN(926)
Abstract:
The Campos Basin in Brazil is a typical passive continental margin basin of Atlantic type.It has experienced 3 stages of tectonic evolution including rifting,transitional and drifting,and the corres-ponding sequences of continental facies,evaporate rock and marine facies have been deposited respectively.During the rifting stage,the black lacustrine calcareous shale in the continental sequence worked as the main source rock.The evaporate rocks in the transitional sequence divided the reservoirs in the basin into 2 sections: pre-salt and post-salt.About 90% of the total reserves of the basin have been found in the turbidity sandstones in the marine facies sequence deposited during the drifting stage.The most important petroleum system in the basin is Lagoa Feia-Carapebus.Petroleum generated from the source rocks in Lagoa Feia Group migrated along faults into the turbidity sandstones in Carapebus Formation of Campos Group.Petroleum distribution was mainly controlled by source rock burial depth,evaporate rock generation,turbidity sandstone distribution and fault generation.
Features of gas released from heated igneous rock, Tarim Basin
Zhu Dongya, Meng Qingqiang, Xie Qilai, Jin Zhijun
2011, 33(5): 526-530. doi: 10.11781/sysydz201105526
Abstract(2790) PDF-CN(821)
Abstract:
The fluid entrapped in Permian igneous rocks collected from the north and the center of the Tarim Basin has been studied using heating method so as to analyze the features of fluid from deep strata.The total amounts of gas released from the 2 igneous rock samples collected in the central Tarim region are 1 902.7 μL/g and 1 517.7 μL/g,much higher than those of the 5 igneous rock samples collected in the northern Tarim region(515.2-691.5μL/g).In both the central and the northern Tarim regions,gas release amounts reach a peak during the medium temperature stage(700℃).CO2 is the dominant compound in released gas from each sample during each temperature stage,and reaches as high as 91.47%.N2 and SO2 are also important compounds in released gas,and have high contents in some samples.CO,H2,hydrocarbon and noble gas are found in released gas more or less.The 40Ar/36Ar ratios of released gas are high,usually between 450.3 and 1 170.3,indicating deep source.However,the 3He/4He ratios of released gas are low(0.0091-0.091Ra) except for one diabase sample(0.35 Ra),indicating crust source.The reason is that He in igneous rocks mixes with that in crust due to diffusion effect.
Pathway tracing of crude oil filling in Fuyang oil layer, Wangfu Sag, Songliao Basin
Jiang Xingchao, Wang Tieguan, Chen Jianfa, Feng Zihui, Wang Xue
2011, 33(5): 531-535. doi: 10.11781/sysydz201105531
Abstract(3270) PDF-CN(839)
Abstract:
Based on the filling pattern of sandstone reservoir,according to the minor variation of crude oil maturity in reservoir,the filling pathway has been traced with maturity contour.The peak of maturity contour refers to the advanced pathway for petroleum migration and filling.4 parameters which are not influenced by other geologic factors have been chosen in the studies of petroleum migration and filling pathway in Fuyang oil layer,Wangfu Sag,including tricyclic terpanes/17α(H)-C30 hopanes ratio,Ts/(Ts+Tm) ratio,C29 sterane ββ/(ββ+αα) ratio,and C30 diahopanes/17α(H)-C30 hopanes ratio.17 samples from Fuyang oil layer have been analyzed,indicating that crude oil maturities all over the Wangfu Sag have the same feature.Well Shuang 32 is the filling point which is close to source kitchen.There are 3 advanced migration and filling pathways in the study region: 1)from well Shuang32 to well Shuang26—Shuang301—Shuang31 in NE direction;2)from well Shuang32,crossing well Shuang38,to well Chang64—Chang11—Chang17 in NWW direction;3)from well Shuang32 to well Shuang231—Shuang23 in NW direction.
Petroleum origin and source in Shidong area, Junggar Basin
Li Lin, Chen Shijia, Yang Disheng, Lu Jungang, Zhao Kebin, Xu Huaimin
2011, 33(5): 536-539. doi: 10.11781/sysydz201105536
Abstract(2963) PDF-CN(1053)
Abstract:
Shidong area locates in the west of the Dishuiquan Sag of the Junggar Basin,adjacent to the Shixi oil field(with 108 treserves) and the Kelameili gas field(with 1011m3 reserves).High-yielding oil-and-gas flows have been found in the region;however,production scale is small and the origin and source of petroleum are not clear yet.The whole-hydrocarbon geochemistry method has been practiced in petroleum source analyses.The dry coefficients of natural gas in Shidong area are high,and the carbon isotopes of methane and ethane are heavy,which is different from those in the Shixi oil field and similar with those in the Kelameili gas field.Crude oils from both deep and shallow formations in Shidong area have the same characteristics basically.Carbon isotope,pristane/phytane ratio,chromatography-mass spectroscopy of light and saturated hydrocarbon of crude oil in Shidong area are not the same as those in the Shixi oil field,and similar with those in Jurassic of well Lunan1 region around the Dishuiquan Sag and those in the Kelameili gas field.The studies have indicated that the petroleum in Shidong area comes from the Dishuiquan Sag rather than the Shixi oil field.
Catalytic hydropyrolysis of over-mature source rock in northeast Sichuan Basin
Yue Changtao, Li Shuyuan, Ling Ruifeng
2011, 33(5): 540-545. doi: 10.11781/sysydz201105540
Abstract(3034) PDF-CN(910)
Abstract:
The over-mature kerogen samples from the northeast Sichuan Basin were studied by catalytic hydropyrolysis in a fixed-bed reactor.The products were analyzed with GC-MS and were compared with source rock extracts.The distribution features and geochemical information of sterane,terpane in saturate hydrocarbon and dibenzothiophene and fluorene in aromatic hydrocarbon were studied.According to parameters such as hopane index,Pr/Ph,gammacerane index,regular sterane/17α(H)-hopane,C27-C28-C29 regular sterane,rearranged sterane/regular sterane,dibenzothiophene and fluorene,the source rocks in the northeast Sichuan Basin were marine carbonate ones with little clay deposited in anoxygenous and unhypersaline environment.The biogenic sources were plankton.
Application of single cold trap pyrolysis chromatography in source rock evaluation
Jiang Qigui, Ma Yuanyuan, Li Xin
2011, 33(5): 546-551. doi: 10.11781/sysydz201105546
Abstract(3021) PDF-CN(894)
Abstract:
By means of single cold trap pyrolysis chromatography,the pyrolysis analyses of source rock samples have been carried out.Combining electromagnetic cutting with cold trap enrichment,the hydrocarbon components of source rock during different mature stages have been analyzed with pyrolysis chromatography,and gaseous hydrocarbon has been separated well,providing technical supports for dynamic studies of source rock components.As to different types of source rock,from type Ⅰto Ⅲ of organic matter,the yielding rate of methane increases rapidly while the yielding rates of light and black oils decrease gradually,and the yielding rate of wet gas does not change obviously no matter which organic types it belongs to.The n-alkanes/n-alkenes ratios of pyrolysis product of source rock are controlled by pyrolysis rate,source rock evolution stage and type,hence the ratio can not be used to judge organic matter type.The dynamic analyses of hydrocarbon pyrolysis component in source rock provide data including C1(dry gas),C2-C4(wet gas),C5-C14(light oil) and C15+(black oil),offering important parameters for source rock quantitative evaluation,oil and gas major generation stage determination as well as the calculation of oil/gas ratio and total resource.
Application of X-ray fluorescence logging technique in lithologic identification:A case study in wells YB10 and YB22, Yuanba region, northeast Sichuan Basin
Wang Jing, Gao Lin, Fu Zheyi, Wang Jinyi
2011, 33(5): 552-558. doi: 10.11781/sysydz201105552
Abstract(3063) PDF-CN(879)
Abstract:
New techniques such as air drilling,PDC and impregnated bit + fast-spiral screw have been practiced widely in Yuanba region of the northeast Sichuan Basin;however,fast drilling and fine or even powdered detritus have made it difficult to identify lithologic characters and formation boundaries for common well-logging.The X-ray fluorescence logging technique is not restricted by small detritus size or short analysis period.It deals with the contents of 14 elements such as Mg,Al,K,Si,S,Ca and Fe in rock samples so as to analyze lithologic features and to identify formation boundaries.The new technique was practiced in well YB10.4 115 samples collected from 702-7155 m deep were analyzed.According to element contents and curve changes,combined with outcrop lithologic data,continental sandstone and mudstone as well as marine carbonate rock were distinguished.The results were accordant with electric logging data in 92.60%.