礁滩相储集层平面非均质性定量表征技术

受沉积、成岩、构造破裂等作用影响,礁滩相储集层平面非均质性较强,但由于储集层孔隙类型多样,孔—渗关系复杂,储集层渗透率定量预测难度大,加上目前多借用碎屑岩表征参数和表征方法,致使储集层平面非均质性难以定量表征。以普光气田为例,通过分析礁滩相碳酸盐岩储集层非均质性影响因素,运用统计学中的主因子分析方法,优选出颗粒岩厚度百分比、隔夹层个数、孔隙度、基质渗透率、裂缝渗透率五项评价参数;而针对具有复杂孔隙结构特征的礁滩相储集层基质渗透率参数的取值,则引入反映孔隙形态和连通性的"孔构参数",开展储集层渗透率的测井精细解释与地震预测;以四级层序为研究单元级次,优选综合指数法,对井点上储集层非均质参数进行计算;再在传统数理统计方法评价储集层平面非均质性基础上,进一步采用地震预测渗透率反演数据体震控、沉积微相相控的多级约束,运用地质建模技术,定量评价了气田平面非均质性。研究成果较好的指导了气田开发动态分析、措施方案制定等,对气田开发具有重要意义。     

基于深度学习的地层沉积正演模拟代理模型构建与应用

地层沉积正演模拟方法能更真实地刻画地下地质体的分布规律,比传统的基于地质统计学的建模更有优势,但是条件化难度大,使其应用在实际油藏地质建模时面临较大挑战。地层沉积反演模拟提高了该方法的实用性,基于模拟结果与观测数据定量比较,地层沉积反演模拟在全局优化算法的驱动下不断修正地层沉积正演模拟输入参数,使模拟结果与观测数据吻合度达到最佳。由于反演系统优化参数多,非线性极强,收敛难度大,需要的迭代次数多,单次正演模拟耗时长,导致该方法效率较低。地层沉积反演模拟和深度学习算法中的生成对抗网络相结合,提出了构建地层沉积正演模拟代理模型的方法。以大量的碳酸盐岩地层沉积模拟的合成模型作为样本,通过神经网络训练,形成地层正演模拟器的代理模型,然后将其代入地层沉积反演模拟系统,避免了直接地层正演模拟的长耗时,加快了反演模拟的收敛速度。通过巴哈马西缘碳酸盐岩地层沉积模拟验证了该方法的可行性,采用学习后的生成网络进行沉积反演模拟,反演效率得到了大幅提升。尽管本文展示的是二维实例,也有望扩展应用在三维模型上。     

储层非均质性研究方法进展

储层非均质性作为储层表征的核心内容之一,一直是研究者关注的焦点。储层非均质性的研究内容主要包括储层非均质性分类、储层非均质性评价、储层非均质性成因分析和储层非均质性对油气田开发的影响等。国外对于储层非均质性研究主要包括利用各种实验研究储层孔渗等物性特征及其对流体渗流规律的影响、利用野外露头资料开展地质建模和模拟研究进行储层非均质性定量分析。国内主要包括通过沉积学、成岩作用等地质成因分析研究储层非均质性和基于测井精细解释的渗透率等储层物性参数进行非均质性的定量评价等。研究方法有地质成因分析法、层序地层学方法、各种实验研究方法、地质统计学方法、各种数学计算方法、测井解释方法、地质建模方法、地震预测方法、数值模拟方法和生产动态分析法等。结合自身科研实践,分析了不同研究方法的优缺点。在此基础上指出了目前储层非均质性研究中存在的主要问题和今后的发展方向。     

储集层精细描述的新思路

应用高分辨率层序地层，结构单元及流动单元分析的三位一体理论指导储集层的表征建模，从而形成由宏观到微观，静态地质实体与动态开发过程，储集层非均质性与油水分布及流动规律相结合体系是储层精细描述的新思路，以某油田馆陶组河流沉积体系的储集层描述为例说明该方法的有效性。     

储层随机建模方法研究进展

油气储层随机建模方法是近年来新发展起来的一门油气预测技术,它在综合了地质、地球物理信息的基础上,充分利用已知点的储层信息,根据所要预测的储层属性来选择不同的随机模型,从而实现了对油气储层的定量表征及对各种尺度非均质性的定量刻画,其最终模拟结果可以有任意多个以供油藏描述选择。这里简要介绍了目前比较常用的储层随机建模方法、原理,各方法的优缺点,以及不同随机模型的地质适用性,并针对我国储层的特点,指出储层随机建模技术的发展方向。     

基于解释量版的渤海油田巨厚砂砾岩定量表征

渤海油田古近系三角洲沉积发育巨厚（大于100 m）的砂岩和砾岩储层,储层横向变化快,内部非均质性强,地震预测难题大。文章针对此类问题,提出一种基于厚度解释量版的砂砾岩定量表征方法。根据已有钻井资料建立井点处地质模型,结合已有地质资料分析储层可能的变化形式,形成地质模型库,对地质模型库进行正演获得相应的正演地震资料库,然后提取正演地震资料的反射振幅属性,建立不同砂砾岩变化形式下的厚度解释量版,最后提取实际地震资料的反射振幅属性,将其投射到厚度解释量版上,实现对巨厚砂砾岩储层的定量表征。该方法克服了常规地震反演、地震属性等方法难以有效刻画巨厚砂砾岩储层的难题,实现了对具有干涉效应的巨厚砂砾岩储层的厚度及其内部变化的精确定量表征。     

基于非均质地层参数表征的颗粒流模型构建

非均质地层参数的获取与表征方法是浅层地质体改造的重要依据。基于非均质地层的地质建模,表征具有随机不确定性和模糊不确定性的土体表观参数和物理力学参数。利用 Weibull 分布统计描述局部地层信息,并应用Diamond-Square分形插值方法,结合差分盒子维计算非均质地层分形维数,进一步合理演算整体地层参数。采用PFC3D数值模拟软件,结合马尔科夫链蒙特卡洛方法采样数据,对非均质地层块石颗粒及土颗粒进行建模。通过非均质地层模拟结果,发现其破坏过程与应力应变曲线要比均质土体复杂得多,由于块石大颗粒的含量、分布特性对土样力学性质影响显著。本文建模方法有助于非均质地层参数表征研究。     

相控随机建模技术在鄂尔多斯盆地低渗透油藏的应用

鄂尔多斯盆地W油田21井区低渗透储集层非均质性较强,注水开发效果不理想。为了精确描述其储集层物性及展布特征,在地质、测井和开发动态等资料的基础上,综合应用相控建模技术,针对鄂尔多斯盆地低渗透油藏采用多种建模方法相结合的手段进行了建模研究,依次建立了研究区的构造、岩相、沉积微相以及微相控制下的储层属性等相关模型。同时对油气储集层相控与非相控建模结果进行了对比,对比结果显示相控属性模型对油藏特征的描述和表征更加合理、准确,应用Petrel地质建模与Eclipse数值模拟的一体化无缝连接,使后续的CO₂驱油数值模拟研究也取得了良好的应用效果。这一研究结果直接体现出相控建模技术在鄂尔多斯盆地低渗透油藏的成功应用,也预示着相控建模技术是解决多种沉积微相和非均质性较强的低渗透储集层物性参数相关模拟的有效途径,能清晰地认识和识别砂体连通性及其展布规律,可为低渗透油藏后期开发提供可靠的地质基础。     

基于转移概率地质统计的淮南顾桥矿区松散层含水介质刻画

含水介质的空间分布及其非均质性对地下水流和溶质运移有着重要的影响。以淮南顾桥矿区作为研究对象,为了刻画矿区松散层含水介质的空间分布,使用转移概率地质统计方法建立含水介质的随机模型,对矿区水文地质结构的空间连续性和空间变异性进行表征;并将随机模拟得到的顾桥矿区含水介质剖面图与矿区原始水文地质剖面进行对比。结果表明,基于转移概率地质统计模拟方法可以比较准确地刻画矿区的水文地质结构;模拟剖面与原始水文地质剖面的比较显示模拟结果与实际含水介质空间分布情况有较好的一致性,转移概率地质统计方法在对含水介质非均质性刻画中具有较好的适用性。     

复合韵律油藏纵向非均质影响数值模拟研究

非均质性是储层成岩、沉积等地质过程综合作用的结果。它是影响油气田产量、最终采收率的重要因素。研究以渗透率变异系数、突进系数及级差等三个渗透率参数为基础,在建立的油藏机理模型中定量地表征储层纵向非均质性强度,并运用数值模拟方法分析了纵向非均质性强弱对复合韵律底水油藏剩余油饱和度、含水上升规律及采出程度的影响,从而总结出纵向非均质性对复合韵律底水油藏驱油效率的影响规律。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)     

GEOCHEMISTRY

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861