石油实验地质

2009, 31(1)

Abstract(935) PDF-CN(798)

Abstract:

TIME-SPATIAL DEVELOPING FEATURES OF CO-EXISTED INHERITED AND NEOGENIC STRUCTURES AND THEIR GUIDANCE TO MARINE ORIGIN OIL-GAS EXPLORATION IN THE YANGTZE CRATON

Wu Genyao, Liang Xing, Ma Li

2009, 31(1): 1-11. doi: 10.11781/sysydz200901001

Abstract(1604) PDF-CN(1240)

Abstract:
The study on time-spatial developing features of co-existed inherited and neogenic structures is an important step for the basin-orogeny coupling from a direction of petroliferous basin study to a guidance of oil-gas exploration.The exploration of marine origin oil-gas pool in China has taken a very tortuous road,and now it is in urgent need of new theoretical guiding.Taking the northern part of Upper Yangtze area(the Sichuan Basin) as an example,the paper described the orientation of structural line and its mechanism(coupled evolution with the neighbouring orogenic occurring) in the Precambrian,Caledonian,Hercynian-Indosinian and Yanshanian tectonic stages.A key knowledges for recent good progress of marine oil-gas exploration in the easetrn Sichuan Basin was lithologic-structural compound pool created by the Yanshanian neogenic structure(NE-orientation) acrossing the syn-marine sedimentary neogenic structure(NW-striking),which were named the 2nd and 3rd generation of neogenic structures respectively.In the western Sichuan Basin,the 3rd generation of neogenic structure was NEE-striking.To compare with eastern Sichuan,the paper analysed the orientation of structural line of each tectonic stage in the southern part of Upper Yangtze area(Guizhou) and Middle Yangtze area(Hubei) respectively.An obvious distinction in Guizhou might be that evolution of the epicontinental sea basin was coupled with the Babu-Phu Ngu ocean to the south(instead of the Qinling-Dabie ocean to thenorth of the Yangtze craton).In addition,Guizhou area was influenced by the plume tectonics in Late Permian-Early Triassic.The unique basemental structures(the N-S Huangling continental nucleus and the NE-striking Paleo-Tan-Lu fault zone) in Middle Yangtze area constrained the regional formation and deformation for a long time.Based on what mentioned above,the beneficial districts for marine oil-gas exploration in Guizhou and Hubei areas was discussed,which thought that the North Guizhou Basin(to the north of Guiyang-Anshun in west Guizhou) might be a hopeful area,although the orientations of Late Paleozoic and Mesozoic neogenic structures varied from the Sichuan Basin.

FORMATION AND DISTRIBUTION FEATURES OF THE ABIOGENIC GAS POOLS AND THEIR EXPLORATION STRATEGIES IN THE SONGLIAO BASIN

Zhou Liqing, Jin Zhijun

2009, 31(1): 12-18. doi: 10.11781/sysydz200901012

Abstract(1447) PDF-CN(925)

Abstract:
Abundant abiogentic gas pools were developed in Songliao Basin due to its unique deep lithosphere,crustal structure and regional structure background of rear arc strike-slip pull-apart basin.The abiogenic gas pools are mainly located around the NNE and NWW trend major faults in deep crust,where there is plenty of abiogenic natural gas supply because of intense volcanic activities.Abiogentic hydrocarbon gas pools are mainly located in low-oxygen-fugacity and hydrogen abundant zones in deep crust.Organic and abiogentic pools are mutually accelerated and effected.They share similar migration pathways and their accumulation belts are both located in strike-slip pull-apart related NNE slope breaks and horsts as well as central fault uplifts,strike-slip thrusting related uplifts between sags,big structures connected to NEE-EW nose uplifts,and structure-lithology-layer combined traps.Deep abiogentic hydatogenesis causes corrosion reservoir beds.In the meanwhile,the strong corrosion of CO₂ fluid helps the extraction of organic substance,generating oil and gas combined flow,and there's a good chance of the coexistence of organic and abiogentic hydrocarbon pools.Work for the next phase is to go on exploring the abiogentic gas and combined generated gas in deep fault depressions,and to find the abiogentic gas both in Mesozoic-Paleozoic carbonate sequences in the base of fault depression and in shallow fault depression with intense volcanic activities.

RELATIVE BLOCKS AND CONVERGENCE PROCESS DURING THE CALEDONIAN MOVEMENT IN SOUTH CHINA

Liu Yunli, Zhou Xiaojin, Liao Zongting, Yang Fan

2009, 31(1): 19-25. doi: 10.11781/sysydz200901019

Abstract(1617) PDF-CN(1227)

Abstract:
This paper discussed the plate tectonic movement during the Caledonian in South China by analyzing the feature and origin of relative blocks in Caledonian Movement.During the Caledonian,Xianggui,Gannan Yunkai,Zhemin,Baoshan,Tengchong and Yangzi blocks had all relationship of the cracking of the Rodinia continent.These blocks converge and collide under the background of forming the Gondwana continent in Eopaleozoic.And then multiperioyic Caledonian Movement with different character was formed.The collision matching has the character of soft collision and weak orogenic which appear as the continent margin uplift and collision granite formed in the front of collided landmasses,also in the back and front of collided landmasses the relict seabasin was found.After the Caledonian Movement,the basic tectonic structure of South China had been set up.

PORE EVOLUTION OF RESERVOIRS OF FEIXIANGUAN FORMATION IN PUGUANG GASFIELD IN NORTHEASTERN SICHUAN

Wang Suyi, Jiang Xiaoqiong, Guan Honglin, Bao Yunjie

2009, 31(1): 26-30. doi: 10.11781/sysydz200901026

Abstract(1417) PDF-CN(1004)

Abstract:
The reservoirs of Feixiangaun Formation in Puguang gasfield in northeastern Sichuan are mainly consisted of sediments of platform marginal ooilite beach,with principle rocks of ooilite dolomite and crystalline dolomite.Due to fresh water dissolution in the early stage of diagenesis,some secondary solutional voids were developed.However,these voids and the primary pore were largely filled by early cement.Small amount,normally less than 1%,of intercrystalline pore was formed as a result of dolomitization.Present effective pores mainly are solutional voids and fractures formed during the burial period.There were two stages of burial dissolution,with stage Ⅰ was developed after structural compression but before oil filling.Dissolution was related to acid flow with rich organic acid and carbon dioxide.The pores formed in this period accounted for 40% of present porosity of reservoirs.Stage Ⅱ dissolution was developed after the filled oil was transferred to bitumen.The acid flow might be related to the pro-ducts of themochemical sulfate reduction(TSR).Its porosity accounted for 60% of present reservoirs.In terms of pore evolution,the favorable diagenesis for formation of good reservoirs included dolomitization,structural compression and early and late burial dissolution.

THE SEISMIC FACIES STUDY OF THE LOWER PALEOZOIC AND ITS GEOLOGICAL SIGNIFICANCE IN THE SOUTHEAST MARGIN OF SICHUAN BASIN

Shi Zejin, Tian Yaming, Han Xiaojun, Wang Changcheng, Gao Lin

2009, 31(1): 31-35. doi: 10.11781/sysydz200901031

Abstract(1660) PDF-CN(1045)

Abstract:
Through the seismic method to resolve the geology problem,more and more new way is advanced,however,the traditional seismic facies analysis technique,which has directness contact with the geology factors,is neglected.Based on the seismic facies analysis in the southeast margin of Sichuan basin,the prograding structure seisic facies,slump andenticular seisic facies、wave seismic facies and varied amplitudes seismic facies are identified.Using the seismic facies assemblage analysis method,combined with geological data and the sedimentary facies anasylis of single drill,to study the sedimentary facies and reservoir prediction research,is very easy,and is quite adapt to carry out in the relatively lowdegree exploration areas of lacking drill bores.

THERMAL EVOLUTION AND ITS IMPACTION ON EXPLORATION POTENTIAL IN OVERPRESSURE SEDIMENTARY BASINS-A CASE STUDY ON CONTINENTAL MARGIN BASINS OF THE NORTHERN SOUTH CHINA SEA

Cheng Benhe

2009, 31(1): 36-39. doi: 10.11781/sysydz200901036

Abstract(1440) PDF-CN(935)

Abstract:
It's observed that oil/gas fields distribution is distinctively connected with the geothermal abnormal areas in continental margin basins of the northern South China Sea.This phenomona is basically due to the geothermal fluid vertical movement and the lower thermal conductivity of oil/gas beds during the process of oil/gas reservoir formation.Thermal evolution of sedimentary basin has significant impaction on the range of oil/gas window,and also the maturity of vitrinite reflectance can be restrained as a result of overpressure.Therefore it has been taken into consideration in this paper when the vitrinite reflectance is calculated with EasyRo model.The simulated result indicates that the fact of overpressure has expanded the range of oil/gas window and exploration scope as well.

FORMATION AND DISTRIBUTION OF LARGE-MEDIUM SCALED VOLCANITE GAS FIELDS IN EASTERN CHANGLING FUALT DEPRESSION OF THE SONGLIAO BASIN

Wu Qun, Zhou Liqing

2009, 31(1): 40-45. doi: 10.11781/sysydz200901040

Abstract(1633) PDF-CN(907)

Abstract:
A series of large-medium volcanite(oil) gas fields have been found in the east of Changling Fault Depression in southern Songliao Basin,such as Songnan,Dabei,Dongyingtai,and Dongling gas fields.These volcanite(oil) gas fields have the following accumulation and distribution features.1) These fields are located in the hydrocarbon bearing depression,such as Changling,Qian'an,Chaganhua depressions,which have been proved by drilling to be bearing high quality source rocks of lacustrine and eulimnetic facies of Shahezi-Yingcheng Group.2) A lot of large inherited uplift structure-volcanite combined traps were developed near the fault belts controlling sags with source rocks and in the breaks of the gentle slopes.3) Major gas pools were distributed in massive acidic volcanite reservoir rocks in upper Yingcheng Group,which were covered with the upper sections of Denglouku Group and Quantou Group,as a favorable sealing layer.4) The sands and the fracture as well as volcanic rocks were interlaced to form complicated grid-and blanket-like hydrocarbon migration system and establish a solid foundation for large scale hydrocarbon migration and accumulation.5) In the course of late tectonic evolution since late depositional stage of Denglouku Group,the eastern part of Changling Depression have been remaining favorable accumulation and preserving conditions.Next-step work should focus on the sag-controlling fault belts and breaks of the gentle slopes in Changling Depression,exploring inherited nose-like uplift structure-volcanite combined traps in Yingcheng Group.

TECTONIC AND SEQUENCE-BASED LITHOFACIES PALEOGEOGRAPHIC FEATURES OF LATE TRIASSIC IN WESTERN SICHUAN FORELAND BASIN

Zeng Hongyang, Chen Hongde, Lin Liangbiao, Hu Xiaoqiang

2009, 31(1): 46-49. doi: 10.11781/sysydz200901046

Abstract(1474) PDF-CN(1042)

Abstract:
The Late Triassic in the Western Sichuan Foreland Basin is a key to understand the evolutionary history of this basin.Using bore hole,outcrop,and seismostratigraphic data,the authors studied the tectonic sequence of the Upper Triassic in the Western Sichuan Foreland Basin.The Upper Triassic was divided into three tectonic sequences.Taking the tectono-sequence system tract as the mapping unit,it also systematically maped the lithofacies paleogeographic chart and discussed the evolutionary features.The results indicated that Tectonic Sequence 1(TS1) includes Ma'antang Formation and Xiaotangzi Formation,and it evolve from episode Ⅰ of Indo-Sinian Movement.There were developed neritic and marine-continental transition environment in the Western Sichuan Foreland Basin.TS2 includes the Second and Third members of the Xujiahe Formation.The Western Sichuan Foreland Basin started forming and developed marine-continental transition environment in TS2.TS3 includes the Fourth and Fifth members of the Xujiahe Formation.Because of influence by the Anxian Movement,the Longmenshan Thrust Belt was uplifted and formed mountains,which changed the Western Sichuan Foreland Basin into a terrestrial sedimentary environment.The most important factor controlling the basin formation and evolution of the Late Triassic in the Western Sichuan Foreland Basin is tectonic activity.

HYDROCARBON ACCUMULATIONS SOURCED FROM GAS HYDRATE-AN IMPLICATION TO PETROLEUM EXPLORATION IN PALEOPLATFORMS

Zhi Jiasheng

2009, 31(1): 50-53. doi: 10.11781/sysydz200901050

Abstract(1398) PDF-CN(983)

Abstract:
The free gas,formed by biogenic methane and pyrolysis hydrocarbon,was sealed under gas hydrate stable zone in the ocean(geosyncline) before orogenic movement.It was migrated upward with crustal uplift and thermo-pressure change,and could been accumulated passing through reservoirs.It was proved that the various maccalubers,gas seepage and hydrocarbon reservoirs were formed by gas hydrate in southwestern Taiwan sea area.Therefore,it might be inferred that the overmatured source rocks in orogenic belt provided hydrocarbon to the platform area(late cratonic basin),which could explain the formation of "oil pole" in Middle East and solve the problem of mismatch of gas reserve with hydrocarbon generation amount of source rocks in the Sichuan Basin.

ACCUMULATION STAGES OF STRATIGRAPHIC RESERVOIRS IN THE DONGYING SAG OF THE BOHAI BAY BASIN

Cheng Hui, Chang Yingmei, Jing Yali

2009, 31(1): 54-57. doi: 10.11781/sysydz200901054

Abstract(1533) PDF-CN(958)

Abstract:
The exploration degree in the Dongying Sag of the Bohai Bay Basin is gradually developing.The exploration position of stratigraphic reservoirs is continuously advancing.Comparative analysis of maturity of various crude oil and hydrocarbon source rocks showed that the maturity of stratigraphic reservoirs was high and the hydrocarbon accumulation dating was late.According to analysising the homogenization temperature of fluid inclusions of various oil reservoirs at the sub-structural belt,the hydrocarbon accumulation dating of stratigraphic reservoirs is from the final sedimentation period of the Guantao Formation to the sedimentation period of the Minghuazhen Formation.On the base of the evolution of reservoiring factors in the Dongying Sag,a stratigraphic reservoirs accumulating model was established,which correspond with tectonic history and filling history of basin,moreover it was divided into three stages: accumulation preparation stage,accumulation main stage and hydrocarbon preservation stage.

A STUDY ON GEOTHERMICS AND OCCURRENCE OF GAS HYDRATES IN THE NORTHERN SLOPE OF THE SOUTH CHINA SEA

Wang Lifeng, Zhao Kebin, Huang Xin

2009, 31(1): 58-62. doi: 10.11781/sysydz200901058

Abstract(1381) PDF-CN(987)

Abstract:
The research on gas hydrates focuses potential new energy sources,greenhouse gases effects,and seafloor instabilities.The South China Sea sediment basins containing a lot of hydrocarbon source rock were a possible carbon reservior because of its tectonics and geophysics conditions suitable for the formation of gas hydrates especially with the latest news that gas hydrates samples were acquired there in 2007.This paper presents research showing the occurrence of gas hydrates in the Northern Slope of the South China Sea using the static mode after analyzing 127 thermal data packages.The significant index is the thickness of hydrate stability zone which is controlled by geothermal gradient,phase equilibrium and ratio of methane contents.The maps of the thickness distribution with three possible combinations are displayed.Based on two assumptions,influences on thickness induced by the parameter changes are discussed through numerical analysis.The calculation indicates that geothermics can influence the occurrence of gas hydrates and the geothermal data is one of the most important tools in the gas hydrates explorations.

INFLUENCE OF LARGE-SCALE TECTONIC COMPRESSION EVENTS ON THE HYDROCARBON ACCUMULATION

Miao Hongbo, Chen Honghan, Wang Liwu, Jiang Tao, Qiu Yuchao, Cui Binghui, Liu Qingwei

2009, 31(1): 63-67. doi: 10.11781/sysydz200901063

Abstract(1550) PDF-CN(917)

Abstract:
According to traditional hydrocarbon genesis theory,it is accepted that organic maturity is affected by temperature,time and pressure.After summarizing exploration practices,it reveals that thermal maturity of organic matter is mainly controlled by temperature.So long as the temperature is high enough,substantial hydrocarbon can be generated from source rock.Tectonic movements do not only produce great amount of heat,but also make hydrocarbon generation and expulsion abruptly.Compressive process promote the hydrocarbon generation and migration.In addition,tectonic movements can form a set of traps,which shorten the time from generation to accumulation.Therefore,in areas where tectonic compression are well developed,though shallow buried source rock,they also have the capacity for hydrocarbon expulsion,and can form economic oil reservoirs.Based on these findings,the traditional theory that shallow source rock can not expulse oil should be broke,and regions of marginal basin with intense structural deformation should be taken into the exploratory frontier.

HIGH QUALITY SOURCE ROCKS OF NANTUN FORMATION IN WUERXUN DEPRESSION, THE HAILAER BASIN

Liu Xinying, Deng Hongwen, Di Yongxiang, Gao Xiaopeng, Wang Jinkui, Long Guoqing

2009, 31(1): 68-73. doi: 10.11781/sysydz200901068

Abstract(1442) PDF-CN(1172)

Abstract:
Source rocks of Wuerxun Depression of the Hailaer Basin were investigated to characterize their biological developments,organic geochemistry.Together with wire logs and well cores analyses,three series of high quality source rocks in Nantun Formation were discovered.They all have good organic types,high abundance of organic materials and high hydrocarbon potentials.Combined with geological setting and referred previous study,the criterion of high quality source rocks was established[(S₁+S₂) 20mg/g,chloroform bitumen "A"> 0.3%,TOC>5.0% and HC>700×10^-6],which was fit for the whole study area.Through the method of organic carbon log,the distribution of high quality source rocks was confirmed,which showed that the high quality source rock was mainly developed as thin layere in the Nantun Formation,especially in the upper part.In short,the development of the high quality source rocks contributed greatly to the pool forming.

THE RESEARCH ON ACCUMULATION CONDITION FOR SECONDARY GAS POOL IN PENGLAIZHEN FORMATION, THE SUMATOU STRUCTURE OF WEST SICHUAN

Wang Wei, Xu Guosheng, Ni Gengsheng, Liao Yisha

2009, 31(1): 74-78. doi: 10.11781/sysydz200901074

Abstract(1355) PDF-CN(900)

Abstract:
The shallow gas pool of Penglaizhen Formation,Upper Jurassic located in the Sumatou structure of West Sichuan is a typical subnormal-normal secondary gas pool far from source rock.Based on analysis of its characteristic,the pool-forming conditions can be study.The effective source rock which is thick,of abundant organic matter,of long period and high intension to generate hydrocarbon can supply with a plenty of gas for the shallow gas pool in Penglaizhen Formation.The paleostructure is useful for gas accumulation in the early time and succeed to develop,superposed with now-day good trapping condition.The high quality sand body controlled by sedimentary facies serve as a storage for nature gas accumulation.The preservation conditions show big discrepancy,which is the deeper,the batter.The rules for gas pool accumulation are the early accumulation,middle local destruction,and late adjustment and finalization.The enrichment and high producing of gas are controlled both by structure and sand body,especially the distribution and quality of reservoir are most important.

THE CHARACTERISTICS AND CONTROLLING FACTORS OF THE SURFACE OIL AND GAS GEOCHEMICAL ANOMALY IN THE ORDOS BASIN

Zhao Kebin

2009, 31(1): 79-86. doi: 10.11781/sysydz200901079

Abstract(1316) PDF-CN(893)

Abstract:
Based on the abundant actual data and the joint mapping of these data,the authors systematically studied the characteristics of the geochemical background of the Ordos Basin,and compared the geochemical background values of this basin with those of the main petroliferous basins in China.The results show that the Ordos Basin is characterized by middle to high geochemical background values,and relatively even geochemical field among the main petroliferous basins in China.Comprehensive research result shows that the formation of the background and the anomaly within the basin is the results of the combined reactions of various underground geological conditions,various near-surface sedimentary features and various landscapes.Of witch,oil and gas source is the material basis for the formation of the changes in the near-surface concentration of the geochemical indicators,and acts as the main controlling factor for the formation of the near-surface oil and gas geochemical anomaly.Oil and gas from different sources have different compositional characteristics and can cause different near-surface anomaly combinations.The study also shows that the tectonic movement is the main drive force for oil and gas to migrate vertically and laterally from the source rocks to the reservoirs,the difference in trap types plays a controlling role in the near-surface anomaly combination form or anomaly pattern,while the near-surface sedimentary characteristics and the landscape conditions play an important role in affecting the anomaly distribution regularity and the application effects in near-surface oil and gas geochemical exploration.

ANALYSIS OF ISOTOPES AND DIAGENESIS OF ORDOVICIAN DOLOMITE RESERVOIR IN THE WILLISTON BASIN

Li Wei, Pu Renhai, Qing Hairuo

2009, 31(1): 87-91. doi: 10.11781/sysydz200901087

Abstract(1288) PDF-CN(1012)

Abstract:
As a result of different stages of dolomitization,four types of dolomite rocks occurred in the Upper Ordovician Red River limestones of Williston Basin.Within the four types of dolomite rocks that are laminated micro-crystalline dolomite,burrow filled dolomite,matrix dolomite and saddle dolomite,only the matrix dolomite serves as reservoir with inter-crystalline pores.The composition of oxygen,carbon,and strontium isotopes of the four dolomites are obviously different from that of the isotopes of Late Ordovician marine water.Petrology and geochemistry study shows that dolomitization fluid flows of the former two dolomite rocks should come from Late Ordovician marine water,but today's their isotope composition reflect lateral rebuilding or modification.Reservoir dolomite rocks formed at a slightly higher temperature,and a rather later stage,and their fluid flows of dolomitization might come from marine water of Silurian or Cambrian-Middle Ordovician epoch or from thermal fluid in depth.The formation of saddle dolomites should be associated with deep thermal fluids.Occurrences of dolomitization along certain horizons are probably related to several thin layers of Kukersite shale that contains substantial organic materials in this area.

ORGANIC GEOCHEMICAL CHARACTERISTICS CONTRAST OF TERNARY, SUPERCRITICAL AND CHLOROFORM EXTRACTION-A CASE FROM THE FOURTH MEMBER OF SHAHEJIE FORMATION IN THE DONGYING SAG OF THE BOHAI BAY BASIN

Liu Sibing, Zhu Jianhui, Shen Zhongmin, Yang Xi

2009, 31(1): 92-96. doi: 10.11781/sysydz200901092

Abstract(1675) PDF-CN(883)

Abstract:
In the paper,the extractive contents,group components and chromatography of four source rock specimens in the lower part of the Fourth Member of Shahejie Formation of Paleogene,the Dongying Sag of the Bohai Bay Basin was analyzed,using the methods of the ternary extraction,supercritical extraction and chloroform extraction.The extractive contents showed that the capability of ternary extraction is higher than that of supercritical extraction,and ternary extraction may be a relative effective method especially in the evaluation of higher maturity source rock.The contrast of group components and chromatography characteristics showed that the capability of extracting middle-high carbon number n-alkanes and heteroatom-containing compounds by ternary extraction is higher than that of supercritical extraction and the chromatography characteristics of ternary extract is different from that of chloroform extraction,but the chromatography characteristics of supercritical extract is similar to that of chloroform extraction.

ANALYSIS METHOD OF ROCK NMR AND ITS APPLICATION IN OILFIELD EXPLORATION

Xiao Qiusheng, Zhu Juyi

2009, 31(1): 97-100. doi: 10.11781/sysydz200901097

Abstract(1470) PDF-CN(1081)

Abstract:
Analysis of rock NMR(Nuclear Magnetic Resonance)is a new well logging technique developed in recent years,which is based on hydrogen atomic nucleus forming phenomena NMR under an additional magnetic field.Through repeatly measuring signal of NMR and cutoff value of T₂ at different processing phase,many geological parameters such as porosity,permeability,movable fluid saturation of reservoirs can be acquired.The measurement result is only related to pore structure,interstitial fluid properties and storage state,independent of mineral composition of rock frame,which is useful for the judgement of pore structure and fluid property in low porosity and low permeability,low resistivity and unusual lithology reservoir when facing difficulties in oilfield exploration.This technique realizes migration of reservoir property analysis from indoor conditions to drilling site and extension of analyzed objects from core samples to cuttings.And it has many advantages such as less sample consumption,fast analysis,lower cost,obtaining more parameters and high accuracy.The analysis result can evaluate reservoir property more effective in time combining with other data of detection logging.

THE TWO-STAGE FRACTIONATION MODEL OF METHANE CARBON ISOTOPE FROM THE THERMAL SIMULATION EXPERIMENTS OF SOURCE ROCKS IN THE KUQA DEPRESSION OF THE TARIM BASIN

Cheng Qiuquan, Fan Ming, Huang Jiwen, Chen Zhengfu

2009, 31(1): 101-104. doi: 10.11781/sysydz200901101

Abstract(1542) PDF-CN(934)

Abstract:
Thermal simulation experiments of hydrocarbon generation on coal,mudstone and carbargilite samples of Triassic and Jurassic from the Kuqa Depression in the Tarim Basin were carried out through the temperature from 260 to 540℃ with 40℃ as increment.Carbon isotope of the generated gas and vitrinite reflectance(Ro) of post-experiment solid product were measured.The relationship between carbon isotopic values of methane in gaseous hydrocarbon and maturity of solid products was also obtained.The results of the experiment showed that there is two-stage model of isotopic fractionation during source rock evolution.During immature to mature phase(Ro1.5%),carbon isotopic values of methane became lighter with the increase of temperature(maturity).On the contrary,during mature to overmature phase,it became heavier with the increase of temperature(maturity).However,both in the above two phases,carbon isotopic values of methane and maturity were in linear relation.

COMPARISON RESEARCH BETWEEN OIL AND GAS RELATIVE PERMEABILITIES OF QIAOKOU CONDENSATE GAS RESERVOIR IN THE DONGPU DEPRESSION OF THE BOHAI BAY BASIN

Liu Zhenxing, Wang Lezhi, Xiao Yi, Jin Xiuju

2009, 31(1): 105-108. doi: 10.11781/sysydz200901105

Abstract(1541) PDF-CN(937)

Abstract:
Qiaokou gas reservoir is a typical condensate one in the Dongpu Depression of the Bohai Bay Basin.Condensate oil/gas has complicated seepage flow in strata during the process of production,so the development parameters,such as producing pressure drop,gas well productivity,recovery efficiency and so on are not easy to predict.Focusing on above problems,the paper selected the rock cores of Qiaokou gas reservoir and adopted stable state methods to test relative permeability feathers of conventional,balance condensate,condensate in decompression process respectively.The comparative analysis results indicate that condensate oil/gas system presented feathers of low interfacial tension and more easily flow than conventional oil/gas.The paper predicted the oil/gas recovery efficiency of Qiaokou reservoir by applying pool simulation software and using conventional and balance relative permeability curves respectively.Compared with condensate oil in core experiment,the simulation result of balance oil/gas relative permeability curve can better reflect fluid flow of condensate oil/gas in strata and recovery efficiency of gas reservoir.

2009 Vol. 31, No. 1

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