Effect of Multipoint Heterogeneity on Nonlinear Transformations for Geological Modeling： Porosity-Permeability Relations Revisited     

J A Vargas-Guzmán 《中国地质大学学报(英文版)》2008,19(1):85-92

An analysis of statistical expected values for transformations is performed in this study to quantify the effect of heterogeneity on spatial geological modeling and evaluations. Algebraic transformations are frequently applied to data from logging to allow for the modeling of geological properties. Transformations may be powers, products, and exponential operations which are commonly used in well-known relations (e.g., porosity-permeability transforms). The results of this study show that correct computations must account for residual transformation terms which arise due to lack of independence among heterogeneous geological properties. In the case of an exponential porosity-permeability transform, the values may be positive. This proves that a simple exponential model back-transformed from linear regression underestimates permeability. In the case of transformations involving two or more properties, residual terms may represent the contribution of heterogeneous components which occur when properties vary together, regardless of a pair-wise linear independence. A consequence of power- and product-transform models is that regression equationswithin those transformations need corrections via residual cumulants. A generalization of this result isthat transformations of multivariate spatial attributes require multiple-point random variable relations. This analysis provides practical solutions leading to a methodology for nonlinear modeling using correct back transformations in geology.  相似文献   

Main Controlling Factors on Hydrocarbon Accumulation and Distribution in Marine Sedimentary Sequences in South China     

蔡立国  周雁  白振瑞 《中国地质大学学报(英文版)》2008,19(6):645-655

Multiple source rock assemblages were deposited in the sedimentary provinces in South China in geologic history,and some of them were destructed by and some survived against multiple tectonic movements.Therefore,multiple sources,mixed sources,and uneven distribution of sources occurred in the marine sedimentary basins in South China during the late stage of hydrocarbon pooling.Epidiagenesis of the marine carbonate reservoirs and its modification to reservoir poroperm characteristics determined the formation and the scale of natural gas pools.The exploration practices show that the large to medium gas fields mainly occur in areas with high-quality reservoirs.Detailed study of the paleo-oil accumulations and typical oil and gas reservoirs reveals that the basins experienced multiphase superimposition and modification,leading to the distribution of the Paleozoic paleo-oil accumulations and bitumen in the peripheral areas.The phenomenon that oil and gas production concentrates in the Sichuan basin indicates that the overall sealing conditions of a basin determine the oil/gas potentials and the scale of oil and gas production.This is a critical factor controlling the accumulation and distribution of gas in the marine sequences in South China.The early oil and gas pools in the Yangtze platform left billions of bitumen in the peripheral areas due to the destruction of seals.Since the Himalayan,"late-generation and late-accumulation" gas pools represented by the gas pools in the Sichuan (四川) basin were formed in the marine sedimentary sequences in South China as a result of the change of the sealing conditions.Current gas discoveries appear to be "paleo-generation and paleo-accumulation" gas pools but actually are "late-generation and late-accumulation" gas pools.These patterns of hydrocarbon pooling clearly depict themselves in western Sichuan basin and Weiyuan (威远)gas field.It is revealed that the gas pools in the Sichuan basin were mainly formed as a result of hydrocarbon phase change (thermal cracking of oil to gas),miscible migration,and dynamic equilibration since the Himalayan.A large number of gas pools were formed in the Himalayan and the gas pools in the marine sequences are characterized by late pooling; this kind of gas fields/pools are controlled by:(1) effectiveness of modification and superimposition of the marine basins,(2) effectiveness of the source rocks,(3) effectiveness of the overall preservation conditions,and (4) effectiveness of plays.  相似文献   

Formation Models and Distribution of Oil and Gas Pools in Tarim Basin,China     

龙胜祥 《中国地质大学学报(英文版)》2008,19(6):665-674

This article reports the main formation models and distribution of the oil and gas pools in Tarim basin,China,including (I) occurrence of the found oil and gas pools,(2) main formation models of oil and gas pools,and (3) distribution law of oil/gas pools.Petroleum is distributed widely in the strata of Tarim basin from the Sinian at the bottom to the Neogene at the top.However,the found oil and gas fields are mainly distributed in Shaya (沙雅) uplift,Tazhong (塔中) uplift,and Kuche (库车)depression.This article presents 4 main formation models,namely,early formation and long-term preservation,early formation and late reformation,middle-late multiphase-multisource formation,late single-stage formation.Tarim basin is very rich in petroleum resources.Long-term inherited intrabasinal paleohighs and slope zones are the most favorable areas for accumulation of hydrocarbons,but the types of oil and gas pools are different from area to area.The control of unconformities and faults on hydrocarbon accumulating is prominent in Tarim basin.Preservation conditions are of utmost importance.Formation of some oil and gas pools is the result of reforming and re-accumulating of early accumulated hydrocarbons.  相似文献   

关注苏皖南部地区海相油气资源          下载免费PDF全文

范小林 《江苏地质》2008,32(1):16-18

据苏皖南部地区地表露头及部分井下所发现的海相油气显示表明,这里存在海相油气资源勘探远景,关注这一地区的海相油气资源,如何开展和寻找这类油气资源,将有利于该地区区域性经济建设的可持续发展。  相似文献   

岩石圈深部温压条件下萜烷演化的实验研究     

王传远  杜建国  段毅  周晓成  陈志 《矿物岩石》2008,28(2):76-80

在密闭体系中700℃、压力高达3 GPa条件下进行褐煤加水的模拟实验,分析实验产物中的萜烷的变化规律,进而对高压高温下有机质演化进行研究.实验结果表明,相同压力条件下,温度升高有利于有机质的成熟演化;压力增加会抑制或延迟油气的生成和有机质成熟;五环三萜烷ββ生物构型转化为αβ地质构型所需能量比烯烃双键加氢饱和更高.高温超高压条件下,研究样品中C24四环萜烷存在4种同分异构体,含量由高到低依次包括10β(H)-降A-羽扇烷、10p(H)-降A-奥利烷、C24-17,21-断藿烷和10β(H)-降A-乌散烷.高碳数烷烃在地幔高压力条件下仍可以存在,这为认识超压盆地的油气资源与深层油气成藏及保存提供了新的思路.  相似文献   

贵州鹅项水库沉积物特征及其土壤侵蚀的意义   总被引：2，自引：0，他引：2       下载免费PDF全文

孙旭波  王红亚 《第四纪研究》2008,28(4):769-778

对位于贵州西南部非喀斯特丘原区的鹅项水库中取得的一沉积物样芯（EX-1）做了¹³⁷Cs,TOC,C/N和粒度分析以及矿物磁性测量。通过对这些分析和测量结果进行解译,推测了在过去的45年（1960～2005年）中这一水库的汇水流域内土壤侵蚀强度的相对变化。在这45年中,鹅项水库流域的土壤侵蚀经历了由弱到强再持续减弱的一个过程。将这一推测结果与流域内降水数据和土地利用/覆被变化资料数据相结合,探究了该流域土壤侵蚀强度变化的原因。与贵州西南部典型喀斯特流域的情况相比,在鹅项流域内,土地利用/覆被变化情况对土壤侵蚀强度的影响相对次要,而降水对土壤侵蚀强度变化的影响则更为重要。这可能主要因为与典型喀斯特流域相比,鹅项流域的土层较厚、植被覆盖较好。  相似文献   

大港油田官142断块巨厚砂岩的储层流动单元   总被引：1，自引：1，他引：0  

窦松江  王庆魁  倪金钟  李桂林 《现代地质》2008,22(1):76-80,142

以黄骅坳陷官142断块中生界油藏为例,探讨巨厚砂岩储层流动单元的研究方法。巨厚砂岩储层流动单元研究包括两个层次,一为确定渗流屏障和连通体的分布,二为连通体内部储层渗流差异分析。研究表明,官142断块渗流屏障主要有泥质屏障、钙质砂岩胶结屏障和钙质砂砾岩胶结屏障3种类型。通过对连通体内部砂体渗流差异性分析,将连通体划分为3类流动单元。其中A类流动单元以粗孔、粗喉类型为主,渗流性能好,吸水强度大;B类流动单元储层为中孔、中喉型,渗流性能中等,吸水强度次之;C类流动单元储层多为粉细砂岩、砂砾岩或钙质胶结稍差的储层,吸水强度较差。通过流动单元的划分与研究,对预测该区的剩余油分布规律和优化调整方案提供依据。  相似文献   

吐哈盆地丘东凝析气藏中侏罗统储层流动单元划分     

解伟  马广明  孙卫 《现代地质》2008,22(1):81-85

对吐哈盆地丘东凝析气藏中侏罗统储层的流动单元的划分方法和参数选取进行探讨。针对丘东凝析低渗透气藏的储层和流体特点,纵向上对研究区中侏罗统地层进行小层精细划分,平面上应用SPSS统计分析软件对厚度、孔隙度、泥质含量、流动带指数等4个参数进行聚类分析和判别分析,将研究区中侏罗统储层砂体划分为4类流动单元。结果表明各流动单元的类型与储层物性、沉积微相具有很好的对应关系,能够客观地反映气藏储层的地质特征。虽然丘东凝析低渗透气藏中流动单元的划分和油藏中流动单元的划分没有太大差别,但是参数的选取却与油藏中的存在着明显的不同。  相似文献   

华北安鹤煤田煤储层特征与煤层气有利区分布   总被引：3，自引：2，他引：1  

刘大锰  姚艳斌  刘志华  汤达祯  唐书恒  车遥  黄文辉 《现代地质》2008,22(5)

通过对安鹤煤田采集煤样的煤质、显微组分、煤相、显微裂隙分析,等温吸附、低温氮比表面及孔隙结构和压汞孔隙结构测试,研究了该区煤层气赋存的地质条件、煤层气生气地质特征和煤储层物性特征。并采用基于G IS的多层次模糊数学评价方法计算了该区的煤层气资源量,预测了煤层气有利区分布。研究结果表明,该区煤层气总资源量为1 115.73×108m3,煤层气资源丰度平均为1.18×108m3/km2,具有很好的煤层气资源开发潜力。在煤田中部的四矿到八矿之间的地区以及北部的水冶镇附近地区,煤层累计有效厚度大、煤层气资源丰度高、煤层埋深适中、煤储层孔裂隙系统发育、渗透性高,是该区煤层气勘探开发的最有利目标区。  相似文献   

断层垂向封闭性定量研究方法及其在准噶尔盆地白家海凸起东道海子断裂带应用   总被引：2，自引：0，他引：2  

梁全胜  刘震  何小胡  王德杰  王晓东 《现代地质》2008,22(5)

断层的垂向封闭能力主要取决于断面的紧闭程度和断裂带内填充物的岩性。在定量计算断面正压力和断层两侧地层泥地比的基础上,提出了断层垂向封闭因子(Fvs)的概念,并将其定义为断面正压力与断层两侧地层泥地比的乘积。通过该参数可以定量评价断层的垂向封闭能力。以准噶尔盆地东道海子断裂为例,在建立断层垂向封油、气能力评价标准的基础上,应用断层垂向封闭因子(Fvs)定量评价了该断裂带的成藏期垂向封闭性及现今垂向封闭性,分析了该断裂带对油气成藏的控制作用,得到较好效果。  相似文献