2008 Vol. 30, No. 1

Display Method:
2008, 30(1)
Abstract:
MAIN METHODS SYSTEM OF FINE PETROLEUM EXPLORATION——SEISMIC SEDIMENTOLOGY
Lu Yongchao, Du Xuebin, Chen Pin, Xiang Kui, Li Tao
2008, 30(1): 1-5. doi: 10.11781/sysydz200801001
Abstract:
Seismic sedimentology is a new methods system using depositional environment model based of high-precision seismic data,the modern depositional environment,outcrops and cores to identify the sedimentary unit 3D geometry,the internal structure and deposition process.Fine sedimentary modeling is the base of seismic sedimentology.Forward model technique is the bridge of seismic sedimentology.The main aim is using geophysical techniques to fine describe and explain underground geological body with the geological constrained model and forward model.The key technology used in the Dongying Sag of the Bohai Bay Basin and the Junggar Basin and includes:logging constrained inversion technology,stratal slicing and attribute analysis technology,frequency decomposing technology,etc.Seismic sedi-mentology will become the 21st century's main petroleum fine exploration methods.
ANALYSIS OF HYDROCARBON ACCUMULATIONRULE IN GRABEN STYLE BASIN——A CASE FROM SOUTH CHALUHE FAULT DEPRESSION OF THE YITONG GRABEN
Dong Qingshui, Shi Baoyan, Miao Hongbo, Zhu Jianfeng, Guo Yingying, Zhang yi
2008, 30(1): 6-10. doi: 10.11781/sysydz200801006
Abstract:
Yitong Graben,subordinated to south section of Jia-Yi Graben,is the north-extension part of Tan-Lu Fault Zone.Chaluhe Fault Depression of the Yitong Graben is an graben style basin.According to comprehensive analysis,sublacustrine fan deposit which possesses gravity flow property is the domain sandstone sedimentary in this subsidence.Subaqueous debric flow or collapse-fall accumulational glutenite of inner fan has shut off capacity to hydrocarbon,while,the sandstone of middle fan,to some extent,has storage of hydrocarbon.The sandstone of middle fan is apt to form lithological trap,in case subaqueous debric flow or collapse-fall accumulation of inner fan is developed.Vertically,this style basin possesses comprehensive hydrocarbon potential and is prone to form multiple oil-bearing formations.Meanwhile,horizontally,the profit oil and gas exploration zone is located at basin both sides marginal zone which is away from controlling fault at some distance.Especially,the basin marginal zone where forms fracture is prone to form lithological reservoir.The exploration aim in this style basin should be focused on tongue-shaped lithological reservoir of middle fan and rolling anticline reservoir.
ANALYSIS OF UNDERGROUND DIAGENETIC ENVIRONMENT FAVORABLE FOR OIL AND GAS STORAGE——A CASE STUDY OF WELL RD1, DONGYING SAG, BOHAI BAY BASIN
Zhang Shoupeng
2008, 30(1): 11-15. doi: 10.11781/sysydz200801011
Abstract:
Studies of the upper 4th member of Shahejie Formation of Paleogene in Well RD1 in the Dongying Sag of the Bohai Bay Basin have indicated that,oil-and-gas from the same source rock in different stratum has different characteristics.Some are heavy oil;the others are high-gravity oil with pure color.Gas reservoirs locate deep in the upper 4th member of Shahejie Formation of Paleogene,where dry bitumen are usually found.This phenomenon shows that,oil-and-gas storage conditions are different due to time changes and different underground environments in different stratum.Further studies prove that,oil-and-gas storage time length is determined by underground diagenetic process.Analysis of the upper 4th member of Shahejie Formation of Paleogene in Well RD1 shows that,the specific diagene-tic environment is characterized by feeble acid(pH=5.7-6.8) and oxygen-free(Eh-10 mV) conditions.Diagenetic minerals are also distinct,for example,crowds of authigenic kaolinite and automorphic pyrite as well as blue fluorescence of organic phase under microscope.Oil-and-gas may store for a long time in reservoirs under the above-mentioned diagenetic environment.Over the belt,oil is heavy.Under the belt,oil cracks to gas.Studies of the specific diagenetic environment have great value for petroleum accumulation potential in new and old formations and storage availability of liquid hydrocarbon.
GENESIS AND DISTRIBUTION REGULARITY OF THE TURBIDITE BODIES IN THE DELTA FRONT
Yan Jihua, Chen Shiyue, Jiang Zaixing
2008, 30(1): 16-19. doi: 10.11781/sysydz200801016
Abstract:
The forming mechanisms,the distribution regularities and the controlling factors of the turbidite bodies in the delta front are analyzed systematically based on the in-door flume experiment simulation results.The forming process of the turbidite bodies can be classified into four stages,e.g.the sediment accumulation before slumping,the triggering action,the secondary transportation of sediments and the final deposition of turbidite bodies.The comprehensive analysis results of various genetic mechanisms indicate that the turbidities mainly distribute in four favorable zones between the delta front and the deep water area with apparent zonality.The secondary slumping turbidities associated to the earthquakes and developed in the deep-water depression are one of the most favorable lithological hydrocarbon reservoir types.The main controlling factors of the turbidities in the delta front include the triggering mechanism,the component and the characteristics of the sediments,the bed shape of the prodelta,the water depth,the elevation and subsidence of the water level,and the supply of the sediments,which all affect,directly or indirectly,the formation and the distribution of the turbidite bodies in different aspects.
THE CHARACTERISTICS AND EVALUATION OF FRACTURES DISTRIBUTION IN XUJIAHE FORMATION IN THE WESTERN DEPRESSION OF THE SICHUAN BASIN
Zhou Wen, Dai Jianwen
2008, 30(1): 20-25. doi: 10.11781/sysydz200801120
Abstract:
The sandstone reservoir of Xujiahe Formation in the Western Depression of the Sichuan Basin,is the main gas producing zone of the West Sichuan district.The porosities and permeability of the reservoirs are very poor.The fractures are the major filtration passages in the reservoirs and play an important role in gas containing capability of reservoir.So the feature recognition and distribution of fractures is critical to evaluation of re-servoirs.The author sums up the features of fractures through the analysis of rock core and well log information,and concludes that fractures in the reservoirs are mainly diagonal fractures.The width of fractures mainly is from 0.5 to 2.0 mm and the length of fractures mainly is from 5 to 50 cm.There are two main kinds of fractures in this areas: tectoclase and regional fractures.Taking Fenggu Structure as an example,the author makes the distribution evaluation of tectoclase by the means of distortional stress simulation,structure curvature and structure filtration and distribution evaluation of regional fractures,which has some guide contribution on exploration and exploitation in the areas.
GRAVITY FLOW SEDIMENTARY CHARACTERISTICS AND THE SIGNIFICANCE OF PETROLEUM EXPLORATION IN THE CHALUHE FAULT DEPRESSION, THE YITONG BASIN
Wang Xuli, Zhou Jiangyu, Ma Liang, Jie Yixin, Miao Hongbo, Qiu Yuchao, Li Nan
2008, 30(1): 26-31. doi: 10.11781/sysydz200801026
Abstract:
Lots of subaqueous gravity flow sedimentary bodies were developed in the Eocene strata of Chaluhe Fault Depression,the Yitong Basin.Based on the study of distribution and sedimentary character of gravity flow,four sedimentary types can be recognized: shallow-water and deep-water turbidity current deposits,underwater slide deposits and underwater debris flow deposits.Through the comprehensive analysis of regional geological background,drilling lithology,well loggings and seismic data,it is suggest that underwater slide deposits and underwater debris flow deposits were formed in re-transported and redeposition,which were usually associated with faults.Shallow-water and deepwater turbidity current deposits were developed in the pre-fan delta,and mostly related to the paroxysmal water flow event due to subaqueous distributary channel,and partially to the slump turbidity current redeposition.Based on the oil-gas exploration results,it shows that the turbidity sand-body has developed well reservoir capability and has a successful oil-gas exploration.It has been proved that shallow-water and deep-water turbidite sand bodies have good potentials for oil and gas exploration in this region,which are in Liangjia structural belt of the down-thrown side of the No.2 fault and in the periphery of Wanchang structural belt.
CHARACTERISTICS OF THE SILURIAN HYDROCARBON ACCUMULATION IN THE SOUTHERN TAHE REGION, THE TARIM BASIN
Chen Yuanzhuang, Wang Yi, Zhang Dajing, Zhang Weibiao
2008, 30(1): 32-36. doi: 10.11781/sysydz200801032
Abstract:
The distribution pattern of the Silurian hydrocarbon accumulation in the southern Tahe region,the Tarim Basin has been established and the direction of oil and gas exploration in this region has been predicted based on the research results of the reservoir characteristics,the accumulation conditions and the controlling factors of the hydrocarbons in the Silurian Kepingtage Formation.The sandstone reservoir of the Kepingtage Formation is of low porosity and low permeability,with some high quality thick layers of the shore phase,the delta distributary channel phase,the channel-mouth bar phase and the tidal channel phase developing locally.The Kepingtage Formation sandstone reservoir is characterized by deep burial,large area,low abundance,thin hydrocarbon layer,fault conduit,and superimposition of layers.Hydrocarbons generated from the Cambrian-Ordovician source rocks in the southern Tahe region migrated through the faults,the fractures,the sandstones and the uncomformities in the Upper Ordovician Sangtamu Formation into the Kepingtage Formation and accumulated as hydrocarbon reservoirs.The hydrocarbon reservoirs in the Kepingtage Formation mainly formed during the Himalayan period and can be divided into four types,including anticline reservoir,stratigraphic unconformity reservoir,stratigraphical overlap reservoir and lithologic reservoir.The region around the Silurian erosional pinch-out line is favorable for developing stratigraphic unconformity reservoirs,whereas the area southward is favorable for developing anticline,lithologic and stratagraphic overlap reservoirs.
CHARACTERISTICS OF THE UPPER PALEOZOIC COAL RESERVOIR AND ITS GAS-BEARING POTENTIAL IN SHENMU, THE ORDOS BASIN
Xue Junmin, Gao Shengli, Gao Peng
2008, 30(1): 37-40. doi: 10.11781/sysydz200801037
Abstract:
Studies of longitudinal and horizontal distribution of coal reservoir,macroscopic petrographic types,microcosmic petrographic component,pore configuration and permeability,vitrinite reflectance as well as absorbability in coal-bearing formation of Neopaleozoic in Shenmu area of the Ordos Basin indicate that,coal beds are thicker in the east and west,but thinner in the north and south.Coal bed thickness satisfies the demand of coal seam gas development.Most coal is semi-bright.Semi-dull coal distributes mainly in the eastern margin,characterized by low water cut,medium ash content and high vaporization.Vitrinite takes the first place in petrographic micro-petrological units,and the second is inertinite.Pores are mainly micropores and intermediate pores.Degree of coalification is ascending from north to south in the region of interest,showing low-medium degree entirely.Adsorptive capacity is relatively strong and coal seam gas is saturated,even oversaturated,displaying tremendously potential.Reservoir conditions are qualified for exploration and development of coal seam gas.
STUDY OF FAULT SEALING IN CHEPAIZI REGION IN THE WEST OF JUNGGAR BASIN
Wang Lichi, Yang Yong, Hong Taiyuan, Xia Zhongmou
2008, 30(1): 41-46. doi: 10.11781/sysydz200801041
Abstract:
Faults in Chepaizi region in the west of Junggar Basin are mainly high-angle normal ones with small fault displacements.There are mainly 4 fault types: late faults generated both deep and shallow,interzonal faults,late faults generated only shallow and early faults generated since the early Hercynian.The study region is mainly of bar and bank facies lithologic traps.Fault migration is the key for hydrocarbon accumulation.According to stress analysis,synthetic fuzzy judgment and nonlinearity representation,6 important faults in the region are evaluated with 2 shale smear factor methods.Sealing studies are done in the fault in the south of Well Pai 208 and the fault in the east of Well Pai 17.The faults work as effective sealing in the Taxihe Formation,characterized by opening down and closing up.There are both passages and top sealing for hydrocarbon.The studies have provided useful information for hydrocarbon exploration and got good industry reserves in the region.
STUDY OF SEQUENCE STRATIGRAPHY AND SUBTLE RESERVOIRS IN THE BIYANG SAG OF THE NANXIANG BASIN
Li Haihua
2008, 30(1): 47-51. doi: 10.11781/sysydz200801047
Abstract:
Based on T-R cycle theory,combined with seismic profile reflection characteristics and sequence stratigraphic analysis as well as local well profile sequence stratigraphic analysis,it is discussed in this paper the 3-grade sequence stratigraphic frameworks in the Lower Tertiary,the Biyang Sag,the Nanxiang Basin.The Hetaoyuan and Liaozhuang Formations of the Lower Tertiary in the Biyang Sag are divided into 1 Ⅰ-grade T-R cycle and 4 Ⅱ-grade T-R cycles.The Hetaoyuan Formation is subdivided into 9 Ⅲ-grade T-R cycles.Sedimentary system and sedimentary sequence patterns in T-R cycles in the Biyang Sag are analyzed.Studies of the distribution pattern of subtle reservoirs in the Biyang Sag indicate that,subtle reservoirs are zoned controlled by geologic structure and sedimentary characteristics.Taking into consideration of oil generation,accumulation and overlying formation in the region,the favorable exploration targets in the sag are predicted.
RESTORATION OF PROTOTYPE BASINS OF LATE CRETACEOUS TAIZHOU PERIOD IN THE NORTHERN JIANGSU BASIN
Ren Hongmin, Chen Liqiong, Wang Wenjun, Chen Pingyuan
2008, 30(1): 52-57. doi: 10.11781/sysydz200801052
Abstract:
Based on studies of regional seismic profiles and conglomerate distribution characteristics,original deposition boundaries of the Northern Jiangsu Basin during late Cretaceous are confirmed.Researches of heavy minerals distribution,sandstone thickness changes and connected profiles of wells have found out sedimentary sources.Combining seismic facies and single-well facies,sedimentary facies of the region are restored;hence the prototype basin is also restored.When the 1st member of Taizhou Formation of Upper Cretaceous is deposited,the Northern Jiangsu Basin is divided in to the Dongtai Depression and the Funing Depression by the Jianhu Uplift.Uplifts in the 2 depressions control sedimentary thickness.Sedimentary materials come from the Tongyang,Lusu and Jianhu Uplifts.When the 2nd member of Taizhou Formation is deposited,the Northern Jiangsu Basin is an integrated basin.The east of the basin is dominated by lake facies and the west by fluvial and flood plain facies.Sedimentary materials come from the Tongyang and Jianhu Uplifts,yet the amount is relatively smaller.
FAULT SYSTEMS AND THEIR TECTONIC EVOLUTION IN XUANHAN-DAXIAN AREA, THE NORTHEASTERN SICHUAN BASIN
Tang Daqing, Chen Xinjun, Zhang Xianping
2008, 30(1): 58-63. doi: 10.11781/sysydz200801058
Abstract:
Faults and fault related folds are the most important and typical structure in Xuanhan-Daxian area,the northeastern Sichuan Basin.They decided the primary reservoirs' preservation and the secondary reservoirs' reconstruction.Based on the detailed interpretation of about 500 km2 of 3-demension seismic data,the fault systems in Xuanhan-Daxian area have been divided into three systems:the fault system of Silurian bottom,the fault system of the middle structural stratigraphic and the fault system of the upper structural stratigraphic.The later two fault systems are the most important fault systems in this area.The fault system of Silurian bottom is very abnormal and it may be formatted in Indosinian Movements epoch.The fault system of the middle structural stratigraphic is the most important one in this area,it has good heredity and formatted the main structure traps in this area,the main system of NE direction formed in Yanshanian Movement epoch and controlled the primary reservoirs' formation and preservation.The fault system of the upper structural stratigraphic formed in the two periods of the early and later Himalayan Movement epoch.The main fault system in NW direction superposited on the fault system of the middle structural stratigraphic and reconstructed it in vertical direction.It also play a significant role in the secondary re-servoirs' formation,preservation and reconstruction in Puguang and Maoba chang areas.
THE RESEARCH OF OIL-GAS DISTRIBUTION CHARACTERISTICS IN THE LANGGU SAG OF THE BOHAI BAY BASIN
Song Rongcai, Zhou Wen, Dong Shuyi, Zhang Shaonan, Ren Wenbo, Zhang Jianfeng
2008, 30(1): 64-68. doi: 10.11781/sysydz200801064
Abstract:
The recent work has already come into the stage of subtle reservoir exploration period in the Langgu Sag of the Bohai Bay Basin.So it is the key issues to instruct next exploration direction that know the distribution characteristics about all kinds of pools in the sequence stratigraphic framework.By means of comprehensive analysis of sequence characteristic and deposit distribution combination,established formation pattern of diffe-rent tectonic unit in the Langgu Sag.And those are taken apart more in different sedimentary system and its combination styles.From the whole deposit and structural background,build on the distribution characteristic of the reservoir in the sequence framework.Six deposit formation patterns were established in the actic,billabong and center regions.And point out that the more sedimentary systems,more tectogenetic movement,the matching of source layer-reservoir-encirclement make importance action to the distribution and enrichment of structure and subtle hydrocarbon pools.
DIAGENESIS OF UPPER TRIASSIC RESERVOIR DETRITAL ROCKS IN WEST AND NORTHWEST OF SICHUAN BASIN
Wang Baoqing
2008, 30(1): 69-74. doi: 10.11781/sysydz200801069
Abstract:
The upper Triassic includes the Xujiahe Formation and the Xiangxi Group in the west and north-west of Sichuan Basin.The main types of sedimentary facies are fluvial-dominated deltas,embayment,lake and alluvial fans.The upper Triassic reservoir rocks consist of feldspathic litharenite,lithic arkose,litharenite,subarkose and sublitharenite.Clastic grains,which contain abundant feldspar and rock fragments,make up 81% to 95% of rocks by volume.Sandstones are characterized by low composition maturity and high texture maturity.Primary porosity lost 45.0% to 77.5% due to compaction effect.Cementation,including precipitation of authigenic quartz,feldspar,clay minerals and carbonate minerals,is the second process contributing to porosity reduction.Influenced by organic materials,the δ13C values for carbonate cements,which range from-4.85‰ to 2.91‰(PDB),are low.Because of leaching with meteoric water and deep burial depth,the δ18O values for carbonate cements,which range from-16.97‰ to-7.86‰(PDB),are also low.Dissolution effect,which is mainly the leaching of feldspar,is the most important process for reservoir quality improvement.Clay minerals are mainly illite,and smectite is absent.Vitrinite reflectance ranges from 0.81% to 2.48%,indicating 85-160 ℃ for most ancient geotemperatures.Diagenesis proceeds to middle-late stage.Fractures have improved reservoir characteristics to a great extent.Because the influence of compaction and cementation is strong,and the influence of dissolution is weak,reservoir rocks are characterized with low porosity and permeability.
ORGANIC GEOCHEMICAL CHARACTERISTICS OF THE LOWER PALAEOZOIC CARBONATE ROCKS IN THE HUANGHUA DEPRESSION, THE BOHAI BAY BASIN
Li yongxin, Geng ansong, Liu jinping, Xiong yongqiang
2008, 30(1): 75-81. doi: 10.11781/sysydz200801075
Abstract:
A study has been conducted on the organic geochemical characteristics of the Lower Palaeozoic carbonate rock samples from the Huanghua Depression,the Bohai Bay Basin.The results show that the distribution of n-alkanes in chloroform bitumen A is characterized by a single peak type,with the main peak carbon at nC16 or nC18;the OEP is approximately equal to 1 and the ratio of C3122S/(22R+22S) homohopanes is between 0.58~0.63,indicating that the organic matter has evolved into a high maturity stage.The Pr/Ph ratio is commonly close to or slightly greater than 1.0,reflecting a depositional environment under a week reducing or week oxidizing condition.In contrast,the distribution of n-alkanes in chloroform bitumen C is characterized by a double peak type,suggesting that the maturity of the organic matter in chloroform bitumen C is lower than that in chloroform bitumen A.The Pr/Ph ratio approaches 1.0,similar to that of chloroform bitumen A,also reflecting a week reducing or week oxidizing depositional environment.The results also show that the carbon isotope pattern of the individual n-alkanes in chloroform bitumen C is similar to that in chloroform bitumen A in most samples,indicating that the carbon isotope of the individual n-alkanes in chloroform bitumen C had not been significantly affected by the post-diagenetic geological processes,and the main characteristics of the organic matter in the early stage has been kept.Therefore,it can be used in paleoenvironmental restoration,and can provide the basis for identifying the potential Lower Palaeozoic primary oil-/gas-reservoirs in the Bohai Bay area.
RESTITUTION OF ORGANIC ABUNDANCE OF THE HYDROCARBON SOURCE ROCKS IN THE WUERXUN AND THE BEIER SAGS, THE HAILAER BASIN
Jiang Fujie, Pang Xiongqi, Jiang Zhengxue, Tian Fenghua
2008, 30(1): 82-85. doi: 10.11781/sysydz200801082
Abstract:
The restitution methods of the organic abundance are classified systematically based on the comprehensive analyses of these methods,and the advantages and disadvantages,as well as the applicable conditions of these methods are comprehensively compared.The results show that the pyrolysis simulation experiment is a relatively better organic abundance restitution method.The organic carbon of the 5 sets of hydrocarbon source rocks from the Wuerxun and the Beier Sags,the Hailaer Basin has been restituted by using this organic abundance restitution method,and the resource amount has been calibrated.According to the results,the restitution coefficients of the organic carbon of the Wuerxun and the Beier Sags are 1.10~1.32 and 1.03~1.18 respectively,with differences between various sets of the source rocks,and about 1.86×108t extra resources has been calculated after the restitution.So restitution of organic matter abundance is very important in correctly evaluating potential petroliferous basins,especially the sedimentary basins with relatively high mature source rocks.
EXPERIMENTAL ANALYSIS OF THE ROCK MECHANICAL PROPERTIES OF THE FRACTURED RESERVOIR UNDER FORMATION CONDITIONS IN THE CENTRAL IRAN BASIN
Xia Zailian, Liu Shugen, Shi Huaxing, Zhou Wen, Zhu Qiang, Xu Guoqiang, Xu Guosheng, Yong Ziquan
2008, 30(1): 86-93. doi: 10.11781/sysydz200801086
Abstract:
The rock mechanical properties of the limestone samples from the Qum Formation between 2 300 m to 3 300 m in Well Arn-2 and Well Fkh-1,the central Iran Basin have been studied under the simulated formation conditions(including the confining pressure,the temperature,the type of the pore-saturating fluid,and the direction of sampling).The results indicate that the compressional deformation characteristics of the rock samples can be classified into 2 types according to the shape of the stress-strain curves: elastic deformation and elastic-plastic deformation.Almost all samples show brittle failure under the formation conditions,with the total axial pre-failure strain being normally less than 3%,and being mostly about 1%.The change scope of the mechanical parameters of all samples are broad due to the great differences in the burial depth;the compressive strength is 46.52 to 288.31 MPa;and the range of Young's modulus is 11.00 to 286.53 GPa.The compressive strenghty,the Young's modulus and the Poisson's ratio of Member E of the Qum Formation in Well Fkh-1 are all greater than those of Member E of the Qum Formation in Well Arn-2.While within the Qum Formation in Well Fkh-1,the compressive strength is greater in Member A than that in Member C than that in Member E,indicating that the compressive strength increases with depth.The effect of the fluid on the mechanical properties in Well Fkh-1 is as follows: the compressive strength and the Young's modulus of the oil-saturated rocks are greater than the compressive strength and the Young's modulus of the water-simulated rocks respectively.When the weak planes pre-exist in the rocks,the compressive strength and the Young's modulus remarkably decrease.For most samples,the compressive strength and the Young's modulus in the direction parallel to the bedding plane are different to those perpendicular to the bedding plane.
ANALYSIS AND APPLICATION OF HYDROGEN ISOTOPIC COMPOSITION OF THE NATURAL GAS
Tao Cheng, Ba Liqiang, Wang Jie, Zhou Yu
2008, 30(1): 94-97. doi: 10.11781/sysydz200801094
Abstract:
The gas chromatography thermo-conversion mass spectrometry (GCTC-IRMS) can be used to detect the hydrogen isotopic composition of the natural gas.An experiment has been conducted first to optimize the MS ion source parameters and the GC conditions.The effects of the H3+ factor,the GC flow rate and the carbon stick-coated conditioning of the thermo-conversion reactor on the analysis results have been discussed.The results prove that this isotopic measurement method has high reproductivity when compared with the numerous analysis results of the certified reference natural gas.The ana-lysis results of the hydrogen isotopic composition of some gas samples from the Sichuan Basin are pre-sented.Combined with the existing regional geological data,the hydrogen isotopic differences between the individual hydrocarbon gases prove that the gas in the shallow Jurassic reservoir in the western Sichuan Basin is coal-formed hydrocarbons from the high to over mature continental source rocks.The results also show that the hydrogen isotopic value of the methane from the eastern Sichuan Basin is higher than-135‰,heavier obviously than that from the western Sichuan Basin,indicating that the gas from the eastern Sichuan Basin is typically characterized by the marine origin.
SUSTAINABLE DEVELOPMENT ABILITY OF PETROLEUM EXPLORATION AND EVALUATION SYSTEM
Xiao Huanqin, Guo Yuanling
2008, 30(1): 98-102. doi: 10.11781/sysydz200801098
Abstract:
For petroleum companies,sustainable development of petroleum exploration is a development model which could satisfy reserve needs both today and in the future.Objective necessity,subjective initiative,timeliness,and interest coordination are the 4 basic characteristics of the model.Sustainable development ability of petroleum exploration refers to all abilities of exploration staff,environment,resource,reserve growth in realizing sustainable reserve increasing.Researches of working ability of exploration staff,environmental adaptability,ability of resources support,reserve increasing ability and so on work as the basic evaluation system of sustainable development ability.The key factor of sustainable development of petroleum exploration is plenty of reserved resources,including both plenty of lower grade upgradeable economical reserves and exploration fields to keep exploration development chronically.Advanced science and technology innovation is also necessary.
A STUDY ON THE MICROFLOW CHARACTERISTICS OF DIFFERENT FLOW UNITS——Taking Hua-152 Block of Chang 3 Reservoir in the Huachi OilfieLd as an ExampLe
Zhu Yushuang, Liu Yiqun, Zhao Jiyong, Dang Yongchao, Bi Yijun, Guo Bing, Liu Zhengwei
2008, 30(1): 103-108. doi: 10.11781/sysydz200801103
Abstract:
A physical simulation experimental study on the micro-flow characteristics of different flow units has been conducted by using the natural sandstone micromodels with the aim to provide a scientific basis for improving exploitation effect.The flow units in Hua-152 block of Chang 3 reservoir in the Huachi oilfield,the Ordos Basin can be classified into 3 types,e.g type A,type B and type C,with the reservoir properties and the permeability properties changing from superior to inferior.The study shows that the microflow characteristics of different flow units are significantly different in the aspects of the entry order of the fluid,the displacement pattern of the fluid,and the type of the residual oil.The fluid always enters into type A flow unit preferentially,then type B flow unit,and is always difficult to enter into type C flow unit.The injection water during oil displacement cannot enter into type C flow unit.As for the difference in the displacement pattern of the fluid,the pattern of oil displacing water is non-piston displacement in type A flow unit,while in type B and type C flow units,the pattern of oil displacing water is piston-like displacement.The types of the residual oils in different flow units are also different after being displaced by water.The residual oils in type A flow unit are mainly small clustered oil block and thick filmlike oils caused by the injection water going around small pore spaces,whereas the residual oils in type B flow unit are mainly larger clustered oil block and spherical or drop-like oils caused by the injection water going around larger pore spaces.The difference in the pore structure and the wettability between different flow units is the main reason leading to the above differences in the microflow characteristics.The experimental study also indicates that type C and type B flow units is the main areas for the residual oil to accumulate,where more exploration efforts should be made.