2003 Vol. 25, No. 3

Display Method:
GEOLOGICAL CHARACTERISTICS AND ORIGIN PECULIARITIES OF LOW EFFICIENCY GAS RESERVOIRS IN CHINA
TIAN Changbing, YU Xinghe, XU Anna, ZHU Yixiang
2003, 25(3): 235-238. doi: 10.11781/sysydz200303235
Abstract:
Low efficiency gas reservoirs as a relative definition refer to a new kind of gas reservoir that is widely occurred in China,and characterized by low porosity,low permeability,low abundance and low deliverability.The resources distribution of low efficiency gas reservoirs is summarized after the systematic analysis of their basic characteristics.The geological characteristics of this new type of gas reservoirs are put forward in terms of trap,sedimentation and rock formation types.The geological factors resulting in low efficiency of natural gas pay zones are discussed with expectation to form the basis of further study of major controlling factors such as the formations of low efficiency gas reservoirs in China and the corresponding geological model establishments.
DIVISION OF PETROLEUM SYSTEMS IN THE MARINE BASINS OF CHINA
HUANG Zeguang, XUE Jianhua, ZHAI Changbo, PAN Wenlei
2003, 25(3): 239-243. doi: 10.11781/sysydz200303239
Abstract(1191) PDF-CN(214)
Abstract:
Based on the petroleum system division of our predecessors,the petroleum systems of Chinese marine basins can be divided into six types,that is,the aulacogen and its succeeding syneclise,the craton basin,the craton peripheral subsidence basin,the foreland basin,the strike-slip basin and the epicontinental fault basin petroleum system.The authors suggested that a complete petroleum system include four connotations practically.The major features of each system were analysed and summarized.The six types of petroleum systems can be further divided into simple and composite two kinds.
APPLICATION OF SEISMIC FREQUENCY SPECTRAL RATIO TO THE PREDICTION OF CHANNEL SANDBODIES
ZHAO Limin, PENG Suping, KANG Hongquan, ZHANG Chaowen
2003, 25(3): 244-246. doi: 10.11781/sysydz200303244
Abstract:
With the development of seismic prospecting and processing technologies,using the seismic information correlated to lithology and oil potential to predict reservoir sandbodies and distinguish oil postential has become one of the important means to increase success ratio of petroleum exploration.But in many cases,geologists can't distinguish the changes of seismic records being resulted from stratigraphy,lithology,or from outside conditions.The seismic frequency spectral ratio technology makes full use of the features that seismic data include rich information.It carefully depicts the transverse variation of seismic frequency spectrum,and can better eliminate the noise influences in seismic records resulted from exciting and receiving conditions so as to project the transverse changing characteristics of lithology and hydrocarbon.It can be applied to distinguish lithology and predict reservoirs.In this paper,the Dawangzhuang oil pool in the Raoyang Say of Central Hebei Province was taken as an example to introduce the prediction of channel sandbodies and lithologic reservoirs by means of the seismic frequency spectral ratio method.Two drilling well sites were determined according to predicted results,and industrial oil flow was obtained by drilling practice.
ANALYSIS ON THE TYPICAL STRUCTURAL STYLES AND DEFORMATION MECHANISM OF THE KELASU TECTONIC ZONE IN THE KUQA DEPRESSION OF THE TARIM BASIN
SUN Jiazhen, LI Lanbin, ZHOU Xinyuan, PI Xuejun
2003, 25(3): 247-251. doi: 10.11781/sysydz200303247
Abstract:
The Kelasu tectonic zone located in the Kuqa Depression of the Tarim Basin is rich in natural gas.Affected by salt-bearing measures,the structural deformation of salt-above layers is not consistent with that of salt-under layers,and it has the features of dual thrust structures.The thrust-nappe-typed drag structre with gentle or deep dipping angles,and the mass-upthrusting structure with deep dipping angles were developed in salt-above layers.And salt under layers are characterized by developing superimposed thrust structures.According to the analysis of lithomechanical properties,the occurrence of thrust faults and the change of structural patterns in salt-above layers are related to the developing thickness and distributive range of plastic saltrock layers.Meanwhile,as saltrock layers are high quality caprocks for natural gas,their thickness and continuous changes are also key factors to result in the differential accumulation of natural gas in the Kela 2 and Kela 3 structures.
ANALYSIS OF HYDROCARBON DISTRIBUTION IN DAQINGZIJING AREA OF THE SOUTHERN SONGLIAO BASIN
YANG Mingda, YANG Minghui, TANG Zhenxing, WANG Yinghui, CHU Xia, WANG Jinfeng
2003, 25(3): 252-256. doi: 10.11781/sysydz200303252
Abstract:
Daqingzijing is a big oil bearing area with over 100 million tons of oil discovered in recent years in the south of the Songliao Basin.Based on analysis of structural,sedimentary,reservoir and oil-forming characteristics,it has been concluded that the distribution of efficient source rocks and sandbodies had controlled the distribution of oil and gas.Oil and gas were mainly inhabited in the distributary channel and mouth bar of deltaic front.Reservoir properties,faults and low-amplitude structures controlled the accumulation of oil and gas.The combination of Baokang deltaic front sandbody and Daqingzijing syncline resulted in different types of oil pools and a wide development of lithologic oil reservoirs.
ANALYSIS ON THE COUPLING OF SUBSIDENCE PROCESSES, MAGMATIC ACTIVITIES, TEMPERATURE-PRESSURE FIELD EVOLUTION AND HYDROCARBON ACCUMULATION IN THE NANPU SAG OF THE BOHAIWAN BASIN
HAN Jinyang, XIAO Jun, GUO Qijun, KAMAYE Tourba, ZHAO Zhongxin, GAN Huajun
2003, 25(3): 257-263. doi: 10.11781/sysydz200303257
Abstract:
The Nanpu Sag,which is located in the northern part of the Huanghua Depression in the Bohaiwan Basin,is a hydrocarbon-bearing sag developed since the Cenozoic.It went through faulting and depression two evolutionary stages.The denudation restoration showed that the infilling of the basin had "e pisodic" subsidence features.By studing on magmatic activities and temperature-pressure field evolution as well as their relations to subsidence ratio,the time sequence of magmatic activities in basin evolution and its coupling relation to sedimentation were determined,and the relationship between magmatic activities and the ancient temperature-pressure field evolution of the basin was distinguished.This will provide new and important research thought and means for the recognition of hydrocarbon accumulation conditions.
CHARACTERISTICS OF VOLCANIC ROCK RESERVOIRS IN THE LINSHANG AREA OF THE HUIMIN SAG
WANG Jinyou, ZHANG Shiqi, ZHAO Junqing, XIAO Huanqing
2003, 25(3): 264-268. doi: 10.11781/sysydz200303264
Abstract:
Core description,well logging interpretation,porosity and permeability data and mercury-injection curves were used in this paper to study the char cteristics of volcanic rock reservoirs in the Sha 1 Member of Linshang area,the Huimin Sag,the Bohaiwan Basin.The volcanic rock reservoirs in this area were mainly composed of volcanic breccia and tuff,and they had different response characters on logging curves.The reservoir spaces of volcanic rocks included intergranular pores,solution openings and structural fractures.The pore structure was characterized by small pores and thin throats and bad pore-throat connectivity and sorting degree,which were the inner factors to result in the bad correlationship between porosity and permeability.Volcanic rock facies affected the development of reservoir spaces of volcanic rocks,and the middle-upper part of volcanic clastic facies and the top of explosion talus facies were the best favorable facies zones for accumulation.And they are the main exploration targets in searching for the oil and gas pools of volcanic rocks in the future.
RELATIONSHIP BETWEEN FLUID POTENTIAL AND HYDRCARBON MIGRATION AND ACCUMULATION-A CASE STUDY OF GUDONG AREA
PENG Cuncang, TAN Heqing, WU Guohua, LIU Shibin, ZHANG Bo
2003, 25(3): 269-273. doi: 10.11781/sysydz200303269
Abstract:
Fluid Potential is a comprehensive representation of all underground fluid energy.Different fluids (oil,gas and water) are affected by fluid potential field and moved according to the respective potential field distribution.Through exploring model of spatial distribution of underground fluid,the structure of fluid systems can be affirmed in a basin,the understanding about migration and accumulation of oil may be improved,the favorable accumulating area of oil and gas is predicated and exploring success ratio is increased.Two types of underground fluid potential in Gudong area can be distinguished: the high potential fields are coincided with the distribution of active generating sag and are main sources of hydrocarbon generation and dynamic force; and the low potential fields are nearly located in the present oil and gas fields.Therefore,the potential area for petroleum migration and accumulation can be ascertained according to the distribution of low potential field.
STUDY OF SUBTLE GLUTENITE RESERVOIRS IN SYN-DEPOSITIONAL FAULT ZONES-A CASE STUDY OF THE SHENGBEI FAULT ZONE IN THE DONGYING DEPRESSION
ZONG Guohong, FENG Youliang, LIU Chenghua, LI Chuanhua, HAO Xuefeng, GUO Yuxin, WANG Weiqing
2003, 25(3): 274-279. doi: 10.11781/sysydz200303274
Abstract:
Based on the principles of tectonic sequence analysis and base-level analysis,high-resolution seismic sections,log curves and lithofacies data,the depositional characteristics of the lowstand sand bodies of Shengbei fault zone in the Dongying Depression and their development and the significance in petroleum geology were studied in detail.It showed that the lowstand sand bodies of the Shengbei fault zone consisted of alluvial fan,fan delta,turbidite fan and mini-delta.The development of sand bodies was controlled by syn-depositional fault and the lower part of the sequences near the fault break zone was favourable for occurrence of subtle reservoirs.
FORMATION AND CONTROLLING FACTORS OF GAS HYDRATES
CHEN Yongjiao, LIU Bin, ZHU Jianhui
2003, 25(3): 280-284. doi: 10.11781/sysydz200303280
Abstract:
Gas hydrates is a kind of crystal of natural gases that are caged in water.They mainly exist in polar region and in seafloor where temperature are very low and pressure are very high,because its formation and existence need special temperature and pressure.All geological factors that could affect the temperature and pressure are the controlling factors of their formatiom and existence.In accordance with ana lysis of controlling factors,a formation model of gas hydrates was proposed,with that may provide an useful clue for exploration of this kind of resource.
INTERLAYER INTERFERENCE AND DIFFERENTIAL INJECTION OF HYDROCARBON INTO A TRAP
WU Shenghe, ZENG Jianhui, LIN Shuangyun, GUO Yanhua
2003, 25(3): 285-289. doi: 10.11781/sysydz200303285
Abstract:
Through physical simulation experiments and the statistical analyses of practical data from oilfields,the authors intended to make a systematic analysis of the influence of reservoir interlayer heterogeneity on the differential injection of hydrocarbon into a trap in secondary migration.It put forth for the first time a concept of critical permeability grade ratio for hydrocarbon injection.In the process of hydrocarbon injection,interlayer interference led to the shielding action of high permeability zones on low-permeability ones,thus making hydrocarbon injection take place only within definite bounds of interlayer permeability grade ratio (or critical grade ratio).The lower permeability limit value of a reservoir has a good relationship of log-log positive correlation with the highest permeability of sandbody within the reservoir.
HYDROCARBON GEOCHEMICAL FIELD EFFECTS AND THEIR APPLICATIONS
JIANG Tao, XIA Xianghua, CHEN Zhechun
2003, 25(3): 290-294. doi: 10.11781/sysydz200303290
Abstract:
Proceeding from the concept of the hydrocarbon geochemical field and its effects,the influent factors of the formation and evolution of the hydrocarbon geochemical field was analyzed.Origin of hydrocarbon geochemical field effects and their concrete expression over an oil and gas accumulation were also discussed.There is obvious relationship between hydrocarbon geochemical field in the surface and oil and gas accumulation in the deep.
HYDROCHEMICAL CHARACTERISTICS OF FORMATION WATER AND THEIR SIGNIFICANCE IN JIANNAN GASFIELD, YUDONG AREA OF WEST HUBEI PROVINCE
PAN Wenlei, LIU Guangxiang, LÜ Junxiang
2003, 25(3): 295-299. doi: 10.11781/sysydz200303295
Abstract:
Analysis on the testing results of conventional components,trace elements and δD、δ18O and δ34S isotopes in the formation water of Jiannan gasfield showed that the longitudinal changes of hydrochemical components in this area were different from those in other oilfields.Several sets of independent and enclosed hydrochemical environments existed instead of positive or reverse-typed hydrochemical sections.They were not congenetic.T3x formation water has good enclosed hydrochemical environments,and the alternation degree of surface water downward is not great.Below T1j2,there are several independent and enclosed hydrochemical environments.Among them,hydrochemical alternation of T1f2 formation water with C2h formation water happened in the Late Yanshanina Himalayan period by fault systems.
CARBON ISOTOPE CHARACTERISTICS AND ORIGIN OF DEEP CRUDE OIL IN THE NORTH SONGLIAO BASIN
WU Heyoug, LI Jingkun
2003, 25(3): 300-304. doi: 10.11781/sysydz200303300
Abstract:
Most of deep source rocks were in high-mature or over-mature stages,and deep oil was found in only three wells in the North Songliao Basin.Carbon isotope of kerogen was heavier in deep formations of the Songliao Basin,but lighter carbon isotope may generate because the enrichment of 12C in fatty side-chains.Carbon isotope was bascally not related to its thermal maturity,but was affected by its origin.Carbon isotope fractionation of oil in the deep was resulted from the primary migration of oil and the crac-king of large molecules in reservoirs.The fractionation resulted in different slopes between the n-alkane carbon isotopic profile of oil and that of its source rocks.Comprehensive analysis indicated that the high mature oil in the deep was generated by the source rocks deeper than the No.1 member of the Qingshankou Formation.
THERMAL SIMULATION TESTING STUDY AND INFLUENCE FACTOR ANALYSIS OF ASPHALTENE PRECIPITATION IN THE CONDITION OF VISCOUS OIL THERMAL RECOVERY-a case study of viscous oil pools in the Xinglongtai oil reservoirs of Du-84 block, Shuguang-1 district, Liaohe oilfield
DANG Ben, ZHAO Hong, WEI Heming, DUN Tiejun
2003, 25(3): 305-309. doi: 10.11781/sysydz200303305
Abstract:
Twelve times of the thermal simulation experiment were done with samples from viscous oil pools in the Xinglongtai oil reservoirs of Du-84 block,Shuguang-1 district,Liaohe oilfield.The results of the experiment indicated that the essential factor resulting in formation damage was asphaltene precipitation.The phenomenon that asphaltene precipitated in pores was very prevalent.The aggregated asphaltene took the shapes of star spots,films,patches or even networks.The damage degree of asphaltene precipitation to porosity and permeability increased with temperature.It increased with pressure when the pressure was less than 11.5MPa,but decreased with pressure when the pressure was more than 11.5MPa.The average damage rate of permeability was above 80%.It belonged to strong damage.The damage rate of porosity was only 1.3%-6.5%.The major affecting factors of asphaltene precipitation were the component of viscous oil,temperature,pressure and solvent.
SEPARATION AND DETERMINATION OF NEUTRAL NITROGEN COMPOUNDS AND ALKYLPHENOLS IN CRUDE OIL
WANG Huitong, XU Guanjun, YOU Jianchang, WANG Peirong, ZHANG Dajiang
2003, 25(3): 310-313. doi: 10.11781/sysydz200303310
Abstract:
A new method to simultaneously separate neutral nitrogen compounds and alkylphenols from crude oil was introduced in this paper.The crude oil in which asphaltane has been removed is put into a non polar C18 column,and the column is eluted by 15mL of hexane and 15mL of dichloromethane in turn.Most saturated hydrocarbon and aromatic hydrocarbon are eluted out after 5mL of hexane has been used.The neutral nitrogen compounds are separated after 6mL of hexane is added and the alkylphenols are obtained as soon as dichloromethane is added.The experiment results showed that the repeatability and stability of the method were satisfied.There are some advantages such as fewer regents,shorter proces sing time and purer neutral nitrogen compounds,compared with other methods.
ANALYSIS OF RESERVOIR ROCKS BY TLC-FID AND ITS APPLICATIONS
WANG Ruxiang, GE Ying
2003, 25(3): 314-317. doi: 10.11781/sysydz200303314
Abstract:
Environmental temperature,humidity,chromatobar activity,quantity of samples,loss of sample and correction factors have influenced on analysis results.Under fixed instrument condition,if environmental temperature,humidity and chromatobar activity were controlled and correction factors were used,the analysis results showed that relative deviation is less than 5%.This has proved TLC FID's feasibility.Comparing with correction samples,the content of the extractives in rocks was calculated.When this technique was applied to describe the geochemistry of oil reservoir of Tahe oilfield,the changes of group composition of fluids were discussed and present oil water contact was determined.
PREDICTING THE FINAL OIL RESERVES IN THE JIYANG DEPRESSION BY USING THE “ZIPF’S LAW”
LUO Jiaqiang
2003, 25(3): 318-320. doi: 10.11781/sysydz200303318
Abstract:
"Zipf's law" has extensively been used in the resources assessment and the analysis and projection of prospecting potentiality in petroliferous basins.The predicted results indicated that the final amount of proved oil resources should be 60.0×108t by using this method in the Jiyang Depression,and showed a good exploration potential.