Fluid Inclusions in the Xichang Basin and Their Applications in Oil—Gas Exploration

Fluid inclusions are commonly observed in various stages during the diage-netic evolution and the generation,migration and accumulation of hydrocarbons in Lower Permian carbonate rocks in the Xichang Basin, providing direct physico-chemical evidence for the process.Altogether seven stages can be recognized,ie.,the penecontemporane-ous, early and mid-late diagenetic stages, the epidiagenetic stage and the early, middle and late reburying stages.Karst and dissolution pores and structural fissures developed during the epidiagenetic and reburying stages constitute the major reservoirs for hydro-carbon accumulation.Oil generation and migration began in the early reburying stage in Late Permian time and developed to its climax in the middle reburying stage in the Triassic period, followed by extensive generation and migration of natural gases during the late stage of reburying in the Jurassic and later periods.The generation,migration and accumulation of hydrocarbons are closely related to Hercynian basalt eruption and Indosinian and Yenshanian tecto-magmatism.     

A Study on Organic Inclusions in Clastic Reservoir Rocks and Their Application to the Assessment of Oil and Gas Accumulations

Terrigenous clastic reservoir rocks are widespread in China,and nearly all the industrial oil and gas accumulations in eastern China occur in the clastic rocks.The study shows that organic inclusions are mostly distributed in the secondary fissures and pores which were ormed in the process of oil-rock interaction,rather than in the cements or secondary enlargements. The organic inclusions are dominantly organic gas-rich or are composed of pure hydrocarbons.Homogenization temperatures range mainly from 120℃ to 130℃，which shows a relatively high maturity of organic matter.Vertical and horizontal temperature changes provide the grounds for the investigation of basin evolution and thermal fluid-kinetics-model.Fluorescence spectral characteristics o the organic inclusions indicate that oils and gases in the area studied probably have experienced two-stage or two-time migration.Micro-fluorescence rescearch is one of the effective approaches to oil/source correlation and oil migration-stage determination.The abundance and occurrence of organic inclusions is one of the indicators of oil and gas abundance and accumulation in rock layers.With the help of other informatio,organic inclusions can provide the basis for the prospective assessment of oil and gas in clastic reservoir rocks.     

Second Hydrocarbon—Generation from Organic Matter Trapped in Fluid Inclusions in Carbonate Rocks

The mechanism and significance of second hydrocarbon-generation from organic matter trapped in fluid inclusions in carbonate rocks are discussed.The types of organic matter and the relationship between them are also reviewed.The organic matter trapped in inclusions and crystals,which account for more than 20%of the total organic matter in carbonate rocks,may be of great significance in the generation of hydrocarbons.High-temperature oil resulting from second hydrocarbon-generation should be an important target,in addition to natural gas,in oilgas prospecting in regions of high-maturity carbonate rocks.     

Analysis of Organic Inclusions Using Fluorescence Microscopy and Micro-FT.IR Techniques

Organic inclusions from the Shahejie Formation of the Eogene period in the Bohai Gulf Basin,eastern China,were examined using micro-FT.IR and fluorescence microscopy in addition to the measurement of their homogenization temperatures(Th).Two populations of organic inclusions were recognized,the primary and the secondary organic inclusions.The primary organic inclusions contain organic materials with relatively long alkyl chains(the carbon atom number is 15 to 17),whereas the secondary organic inclusions contain a certain amount of H2S besides organic materials which have relatively short alkyl chains with the carbon atom number of 5 to 6.The Th values of the primary organic inclusions within the rage of 87-91℃,lower than those of the secondary organic inclusions(Th=98-105℃）,sugesting that the primary organic inclusions experienced a lower degree of thermal evolution than the secondary inclusions.This inference is consistent with the fluorescence spectroscopic characteristics and parameters(Tmax,Q values)of the organic inclusions.Data from the organic inclusions together with the petroleum geology setting revealed that the primary inclusions resulted from the migration of hydrocarbons generated within the strata they are hosted,whereas the secondary organic inclusions were trapped in the process of secondary hydrocarbons expelled out of the source rocks to the locations where they were accumulated.The thermal properties of the organic inclusions are consistent with the maturation of the oil generated from the Shahejie Formation.The abundance of the organic inclusions and their characteristics indicate that the member Es3 of the Shaheije Formation is highly potential for oil accumulation.The results could provide essential coues to petroleum exploration in the Bohai Gulf Basic.     

Characteristics and Applications of Fluid Inclusions in the Eogene System of the Biyang Depression—I.A Fluid Inclusion Study

Presented in this paper are the rypes,salinities,homogenization temperatures and organic components of fluid inclusions formed at the four stages of diagenetic authigenesis in the Eogene of the Biyang Depression.The results of cooling experiments on fluid inclusions were used to determine the fluid system and composition of saline aqueous solution in each of the stages .The homogenization temperatures of saline aqueous solution inclusions and hydrocarbon organic inclu-sions have been corrected by two approaches ,and the trapping temperatures and pressures of fluid inclusions at each of the stages have been obtained.This strdy has shed light on the physicochemistry and evolution of diagenetic fluids.The diagentic fluid system is a system which was transformed from a chloride-bearing to a carbonate-bearing system along with the diagenic evolu-tion.The decrease of diagenetic temperature at Stage III of diagenetic authigenesis suggests that the depression would have experiences uplifting at that time.The fluorescent characteristics of fluid inclusions indicate the varieties of organic components in fluid inclusions both in time and in space.     

Discovery of Early Tertiary Hydrothermal Activity and Its Significance in Oil／Gas Geology,Dougpu Depression,Henan Province,China

Data from the super-deep wells(PS10,PS14 and YS1)led to the discovery of widespread met-al-bearing hydrothermal fluids (or hot brines) related to basic magmas in the Lower Tertiary clastic sequence in the Dongpu Depression .In terms of SEM and EDAX analyses, pore-casting thin section examination of sandstone ,the composition and forming temperature of fluid inclusions ,the trace ele-ment composition of mustone and kerogen and organic geochemical analyses, it is demonstrated that the hydrothermal fluids existing in the area studied are ejecting fluids, which have a close bearing on diagenesis and sedimentation, rather than intrusive veins along the tectonic fractures.The main indicators of hydrothermal activity are:(1)abnormal alteration of kerogen;(2) high-temperature altered mineral assemblage;(30abnormal distribution of hydrocarbons;(4) specific assemblages and abnormal contents of heavy metals in mudstone and kerogen;(5) specific composi-tion of complex compounds and assemblages of fluid inclusions in sandstone;(6) periodic basaltic magma activity.Results of geological observations and laboratory simulating experiments demonstrated that the hydrothermal fluids have a close bearing on hydrocarbon generation in the Dongpu Depression. Two aspects of the effect of hydrothermal fluids are noticed:hydrothermal hydrocarbon production and strong metal catalysis in oil and gas generation.     

莺—琼盆地1号断裂带含烃热流体活动初探

１号断裂带是莺－琼盆地油气勘探的重点地区之一,有机包裹体研究有助于追踪油气及热流体活动的痕迹,为油气运聚成藏提供地球化学依据,通过包裹体薄片镜下观察,均一温度和盐度测试,认为工区内发育五种类型的有机包裹体：（１）液态烃包裹体;（２）气流态烃包裹体;（３）气态烃包裹体;（４）含烃ＣＯ２包裹体;（５）烃子矿物包裹体,含烃ＣＯ２包裹体一般与气态烃共生,含烃子矿物包裹体既无液态烃共生又与气态烃共生,包裹体     

Formation of Strata—bound Ore Deposits in China：Studies on Fluid Inclusions

Fluid inclusion studies were made on the basis of the geological data on the strata-bound ore de-posits of China including those of Pb,Zn,Au,Ag,Sb,U,Hg,W,quartz-crystal and sparry-calcite.An attempt was made to approach the model of formation for each type of ore depos-its by considering the material sources,the migration of fluids and the conditions of mineralization.It is found that ore-forming fluids (especially H2O)originate as heated underground water reacts with the wallrocks and dissolves Na^ ,Ca^2 ,K^ ,Cl^ ,HCl^- and Mg^2 .The ore fluids are mainly of NaCl-Ca-HCO3-H2O system with salinities ranging from 4to 14wt.%.NaCl equivalent and densities ranging from 0.9 to 1.0g/cm^3.It may be concluded that the deposits were formed at temperatures ranging from 150 to 250℃ under pressures from 300 to 1000 bars.Ore deposition may have been controlled by temperature and pressure or by the mixing among different fluids.     

Study on Migration and Transformation Rule of Organic Pollutants （COD） in Aerated Zone

Collecting waste water with a certain concentration of organic pollutants COD (chemical oxygen demand), static adsorption, static biodegradation and dynamic soil column experiments were made in laboratory,we researched migration and transformation of COD in aerated zone. and put for-ward a mathematical model showing the process.The results show that adsorption of organism in aerated zone is linear,which is erprsented by henry‘s law s=Kdc sd, adsorption coefficient Kd=0.0693; biodegradation diagram accord basically with first-order kinetics equation c=coe^-k1t, biodegradation co-efficient K1=0.0499d^-1; dispersion coefficient D=0.0042m^2/d in experiments. The migration and transformation of organic pollutants (COD) in aerated zone jointly result from many factors such as dispersion, adsorption and biodegradation etc..     

马朗凹陷马1井储层长石中有机包裹体研究

根据对马朗凹陷马1井储层长石中有机包裹体的基本特征、均一温度、荧光及荧光光谱分析,得出有机包裹体均一温度为60 ～ 90℃及120～ 140℃,其对应的荧光颜色分别为黄色和蓝绿色。认为储层的油气运移经历了两期,第一期为烃类的主要运移、聚集期,油气为低成熟油;第二期为少量的烃类聚集,并判断出二叠系条湖组该段储层为油气产层。     

海上油藏勘探经济评价方法——以胜利滩海地区为例

正油气勘探经济评价是勘探项目可行性研究的重要组成部分,在此之前经济评价是从探明储量上报开始,在勘探阶段对经济评价工作研究较少,缺乏一套适应当前油气勘探市场形势的经济评价理论和方法(郭元岭,2005)。海上油藏相较于陆上成本更高、风险更大,因此本文针对海上油藏勘探开发特点,利用现金流法建立计算模型,由于勘探阶段资料相对匮乏,本次主要通过数据统计和类比等方法,以最简化的方式     

海上勘察施工特点与施工工艺

海上工程勘察,应根据勘察任务,施工海域水文条件,选择合适的施工平台,根据地层条件,制定合理的施工工艺,确保勘察质量。     

Organic inclusions as an indicator of oil/gas potential assessment of carbonate reservoir beds

Organic inclusions could be formed at the stages of either primary or secondary migration of hydrocarbons so long as mineral crystallization or recrystallization takes place in the sediments, presenting a direct indicator of oil/gas evolution, migration and abundance. Based on the study of organic inclusions in carbonate-type reservoir beds of commercial importance from North China, Xingjing, North Jiangsu, Jianghan, Sichuan and Guizhou in China, many inclusion parameters for oil/gas potential assessment of carbonate reservoir beds are summarized in this paper, including: 1) Types of organic inclusion: Commercially important oil beds are characterized by inclusions consisting of either pure liquid hydrocarbons or liquid plus minor gaseous hydrocarbons, while commercially important gas reservoirs are characterized by inclusions consisting of either pure gaseous hydrocarbons or gas plus minor liquid hydrocarbons. 2) Quantity of organic inclusions: The number of organic inclusions in commercially important oil/gas reservoirs is over 60% of the total inclusion percentage. 3) Temperature of saline inclusions: The homogenization temperatures of contemporaneous saline inclusions in oil reservoirs range from 91–161 °C, while in gas reservoirs from 150–250 °C). 4) Inclusion composition: In commercially important oil reservoirs, C₁/C₂=2−10, C₁/C₃=2−4, C₁/C₄=2−21, (C₂−C₄)/(C₁−C₄)(%)>20, (CH₄+CO+H₂)/CO₂ (molecules/g)=0.5−1.0, and in C₂−C₃−nC₄ triangle diagram there should be an upside-down triangle with the apex within the ellipse, while in commercial gas reservoirs, C₁/C₂=10−35, C₁/C₃=14−82, C₁/C₄=21−200, (C₂−C₄)/(C₁−C₄)(%)<20, (CH₄+CO+H₂)/CO₂>1, and there would be an upright triangle with the apex within the ellipse. The above-mentioned parameters have been used to evaluate a number of other unknown wells or regions and the results are very satisfactory. It is valid to use organic inclusions as an indicator to assess the oil/gas potential during oil/gas exploration and prospecting. This approach is effective, economic, rapid, and easy to popularize.     

重磁综合解释在冀北—晋北地区油气勘探中的应用

本文基于冀北—晋北地区的航磁资料处理解释，结合部分重力资料，从航磁数据拼接与调平、位场转换处理和综合地质解释三方面对冀北—晋北地区开展油气远景评价；通过对研究区的区域地质背景、岩石物性、磁场特征、重力场特征、基底结构进行综合分析，优选出大同、商都、宣怀、多伦-蓝旗和围场5个重点含油气盆地，预测了9个油气勘探有利区，为下一步油气勘探工作提供了方向。     

四川盆地威远气田碳酸盐岩中有机包裹体研究

本文通过对威远、资阳地区上震旦统碳酸盐岩储集层中有机包裹体的研究,提出有机包裹体多分布于储层孔洞缝中所充填的三期矿物中,研究区油气运移的主要通道是溶蚀孔洞和裂缝。并根据不同期次充填矿物中有机包裹体特征、均一温度及单个有机包裹体成分,追索了研究区油气热演化程度、油气运移期次、油气运移的深度和温度。研究结果表明,研究区存在三次主要的油气运移和聚集,其各自演化的程度及油气运移的深度和温度皆不同。     

南海珠江口盆地走滑构造与油气成藏机制

受南海海盆演化以及邻区构造事件的联合控制,南海北部珠江口盆地内部构造表现出明显的多期走滑特征.走滑拉分作用控制了珠江口盆地现今的构造格局,在区域地质构造研究的基础上,本文通过重磁资料,在区域内共识别出NW和NE两组走滑断层,并根据阳江东凹最新三维地震资料的精细解析,识别出花状构造、雁列式和羽状等多种具显著走滑特征的构造...     

The distribution of dimethylcarbazoles in oils from the Pearl River Mouth Basin, South China Sea

C2-carbazole isomers have been investigated in crude oils from the Hui-Liu Structure Ridge (HLSR) in the Pearl River Mouth Basin (PRMB), South China Sea. The NH shielded isomer, as well as the NH partially shielded isomers, was detected in high abundance and the NH exposed isomers in lower abundance. A small-enrichment trend of 1,8-dimethylcarbazole (DMC) was observed in crude oils along the western part of HLSR (WPHLSR), which may indicate little effect of migration on the C2-carbazole distributions. Two strikingly different distribution patterns of NH partially shielded isomers were observed in the reservoirs along the WPHLSR: one with a preference of 1,3- and 1,6-DMCs and the other with a preference of 1,4- and 1,5-DMCs. All of the oils occurring in the Upper reservoirs have a preference of 1,3- and 1,6-DMCs, whereas those trapped in the Lower reservoirs show a preference of 1,4- and 1,5-DMCs, which may indicate there are two petroleum migration systems in the WPHLSR.