基于小波包变换的薄互层识别方法应用研究

薄互储层是我国主要储集油气的地质结构,应用小波包变换的方法对薄互层的识别和层厚度预测研究,提出了一种新的研究薄互层识别的方法。建立楔形模型以及复杂的含有薄互层的模型,并开展了地震正演模拟,根据小波包分解重构理论,应用小波包变换的方法得到合成地震剖面和偏移剖面,实际地震数据结合井信息的标定,对薄互储层的划分和厚度的预测进行了较为详细的研究。模型和实际资料算例结果均表明,小波包变换方法在识别薄互储层中可以突破四分之一波长的限制。     

建南地区须四段致密砂岩含气储层预测研究

建南地区须四段为典型的致密砂岩气地层,其中砂体较厚、砂泥岩互层较多,但储层较薄,尤其是地震响应不清晰,为含气储层的预测增加了难度。为此,以工区储层地质特征为指导,从单井岩石物理分析入手,结合采用叠前弹性反演和AVO分析方法对该区须四段的含气储层分布进行综合预测。储层预测分析表明,本区须四段的储层敏感属性参数对为纵波阻抗(Zp)与纵横波速度比(Vp/Vs),经两者融合的储层因子属性的正高值区可解释为储层砂体的有利发育区;须四段气层主要表现为第Ⅳ类AVO异常响应特征,且该层含气敏感属性为泊松比(PR)、流体因子(FF)、相对纵波速度(DVp),并将三者叠加的烃类因子属性的负异常区域解释为储层有利含气区。最后经综合预测可知,须四段含气储层有效厚度分布在28~80 m之间;且在建35-2井、新店1井周缘区域厚度较大。     

基于AVO效应的薄层预测方法研究

通过地震波波峰和波谷间的距离预测薄层厚度,其垂直分辨率是1/8波长。本文为利用地震资料对更薄地层厚度进行预测,设计反射系数相同和相反的两种楔形模型。同时设计多个厚度不同的CDP道集,利用地层反射系数随炮检距的变化而变化的特点在CDP道集上分辨薄层。通过S变换时频分析方法提取CDP道集的单频剖面,扫描单频剖面的极值点,利用极值点间的垂直距离来预测薄层厚度。通过模型试验表明这种算法对1/16波长厚度的薄层预测效果依然准确,说明这种方法是有效的。     

基于谱反演的薄层预测技术应用探讨

本文从实际的地质地震模型出发,分析了实际情况下峰值振幅、峰值频率随地层厚度的变化规律,其与Widess模型得出的结论有很大的不同:在地层厚度减为零时,峰值振幅并未减弱至零;峰值频率随着地层减薄有逐渐变大的趋势,当层厚小于一定厚度(调谐频率转折点)时,峰值频率开始减小,在层厚为零时与子波的主频一致。当地层薄到一定程度后,峰值频率会与厚度产生强烈的关联,这表示地震对薄层的响应远比我们之前想象的要敏感的多。基于以上理论分析,本文采用谱反演薄层预测技术对FL地区茅口组岩溶薄储层进行预测,精确识别出了薄储层的顶底界面,取得了良好的应用效果。     

C/O测井仪器的灵敏探测位置

利用蒙特卡罗数值模拟技术,研究了C/O测井仪不同源距探测器对不同厚度薄层的响应,以及地层孔隙度、仪器直径变化时,长、短源距探测器对同一薄层的响应.计算结果表明,C/O测井仪的灵敏探测位置在源和探测器之间,距探测器中心的垂直距离约12 cm,并且该灵敏探测位置不受仪器、井眼或地层性质的影响.     

歧口凹陷西斜坡沙一段薄储层预测

歧口凹陷西斜坡沙一下亚段的地震反射同相轴是复杂岩性的综合地震响应,不具备等时性,不能利用追踪地震同相轴和常规反演方法预测储层分布.针对该地区沙一下亚段储层单层厚度薄、横向岩相变化快的特点,首先采用沉积旋回分析法将所研究的目的层划分出3个五级高频旋回层序,并归纳了岩相序列模式;再利用有色反演沿层切片法,检测出薄互层地层中高波阻抗体的形态及其在时间域上的变化;最后以岩相序列模式分析法解释反演结果,实现了五级高频旋回层序内的岩相重构,最终预测出该地区沙一下亚段厚度为3～9 m的生物碎屑灰岩薄储层的平面分布,达到了储层分布预测的目的.研究表明,对于薄层、多种高波阻抗岩性共存的地层,应用地质一地球物理信息的岩相重构方法可以减少地震储层预测中的多解性风险.     

歧口凹陷西斜坡沙一段薄储层预测

歧口凹陷西斜坡沙一下亚段的地震反射同相轴是复杂岩性的综合地震响应,不具备等时性,不能利用追踪地震同相轴和常规反演方法预测储层分布.针对该地区沙一下亚段储层单层厚度薄、横向岩相变化快的特点,首先采用沉积旋回分析法将所研究的目的层划分出3个五级高频旋回层序,并归纳了岩相序列模式;再利用有色反演沿层切片法,检测出薄互层地层中高波阻抗体的形态及其在时间域上的变化;最后以岩相序列模式分析法解释反演结果,实现了五级高频旋回层序内的岩相重构,最终预测出该地区沙一下亚段厚度为3～9 m的生物碎屑灰岩薄储层的平面分布,达到了储层分布预测的目的.研究表明,对于薄层、多种高波阻抗岩性共存的地层,应用地质一地球物理信息的岩相重构方法可以减少地震储层预测中的多解性风险.     

深层砂泥岩薄互层的地震识别方法

深层砂泥岩薄互层油气藏是一类典型的低孔、低渗型油气藏,储层一般具有埋藏深、横向变化快、深层物性差的特点。利用常规的薄层定量描述方法只能识别地层厚度不小于λ／4的孤立薄层,很难实现精细解释。为此,采用正-反演联合预测技术,通过建立符合地下实际情况的的地球物理模型,从正演角度分析目的层的地震波场特征;同时对正演结果进行模型反演,定量分析反演砂体的横向及纵向展布特征。结果表明这种基于模型正演的地震识别方法既能够发挥地震资料在地层横向展布上的优势,又能够提高纵向上的解释精度,为识别前梨园地区深层砂、泥岩互层结构的隐蔽性储层提供参考。     

AVO技术在高邮凹陷永安-联盟庄地区岩性油藏预测中的应用

针对永安-联盟庄地区构造复杂、地层可对比性差、勘探难度较大的问题,以戴南组二段的E2d25亚段为例,首先对研究区进行测井数据的岩石物理分析,确定该区目的层段的敏感参数;然后,以该区宽方位采集的叠前地震数据为基础进行AVO模型正演,分析已知油、水和岩性及其不同组合条件下的AVO特征,并判断该区为第一类AVO特征;最后以2口井为约束进行AVO叠前反演,得到一系列的AVO属性,结合之前的研究结果,优选PG属性和敏感因子F属性对目的层段进行有利区域的预测。结果显示,E2d25层段有利区域主要集中在该区北东方及南西方,大多数有利区域靠近汉留断层一带,储层具有厚度薄、横向连续性差的特点。该结果的提出希望为将来勘探开发工作提供借鉴。     

薄互层疏松砂岩储层时移地震AVO研究

针对薄互层疏松砂岩油藏特征,提出了基于各向异性介质理论的时移地震AVO响应分析方法。利用测井数据和实验室岩石物理测量数据,确定了适合目标油田储层的高孔低胶结岩石物理模型,利用移动平均法计算薄互层油藏Backus参数,从而计算岩石弹性参数变化和分析Thomsen参数变化,计算各向异性介质界面反射和透射系数,利用测井资料合成角道集,分析了油藏含油饱和度和压力变化时的时移地震AVO效应。模拟数据分析表明,疏松砂岩对油藏有效压力变化十分敏感,含油饱和度与压力变化时,PP波和PSV转换波的时移地震AVO响应是不同的。研究表明,地震模拟是进行时移地震可行性分析和有效区分油藏压力与含油饱和度变化的重要工具,对于充分挖掘我国油田潜力具有重要意义。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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