国家地震台数据断记统计及批量补数自动处理

在VS2015开发环境下,使用C#语言编写国家地震台断记统计和批量补数自动处理程序,实现数据中断统计查询、数据采集器波形数据文件下载和上传波形数据文件至远程服务器的自动化。该自动处理程序在部分地震台使用以来,运行良好,数据完整率、连续率得到保障。     

南堡凹陷奥陶系潜山精细构造解释和储层预测综合研究

随着冀东油田勘探开发进程的不断深入,在2006年南堡凹陷大连片地震处理的基础上开展微构造、薄互层、精细油藏描述等问题研究的目标攻关处理.依托高分辨率、高保真和高信噪比的新数据体,开展南堡奥陶系潜山的精细构造解释和储层预测研究,结合多种技术进行井震标定分析,确定各地质层位的地震反射特征,并在工区内测井信息的参考下进行横向追踪,落实主力含油层段构造.在构造解释的基础上综合利用相干技术、蚂蚁体追踪技术和地震相分类技术等对南堡奥陶系潜山储层进行预测,评价出可以优先施钻的6个构造圈闭.     

大井间距井间地震观测试验

介绍了井间地震数据采集方面取得的最新进展．为了使我国井间地震技术实用化,开展了大井间距井间地震数据采集试验．通过地面浅井激发深井接收、深井激发深井接收、不同炸药量、不同传播距离试验,确定了井间地震观测参数．应用改进后的井中安全炸药震源、一个三分量井中检波器和常规数据记录系统,在陕北顺宁油田的顺3井、顺4井和顺5井3口生产井中成功采集到两对大井间距、深井、油井中的井间地震资料,两对井的井距分别为307．92m和470．36m,采集井段为904．31-1272．32m．共设计了4种观测方式,采集到800多炮井间地震记录,对油井无损害．改进型井中安全炸药震源在使用效率和寿命方面有显著提高,可用于商业性并间地震数据采集．     

浅层地震勘探资料处理中的速度分析参数选取

浅层人工地震勘探是当前城市地震活断层探测的主要方法,勘探精度不仅受激发、接收等因素的影响,还与地震数据处理的精度密切相关。速度分析是地震勘探资料处理中的关键环节,它的准确与否对动校正、共深度点叠加、叠后偏移及时深转换等都将产生影响。针对浅层地震资料目的层较浅、叠加次数少和城市背景干扰大等特点,文中对速度分析的参数选取问题进行了研究。首先通过对相邻CDP道集内各接收道炮检距的分析,以及单个和多个CDP道集的对比,提出了用于速度分析的CDP大道集的抽取原则。并通过对不同的CDP大道集、速度扫描间隔、计算时窗长度、动校切除比例等所获得的速度谱的对比分析,对速度谱扫描过程中各参数的选取提出了建议,并对速度分析及时深转换过程中值得注意的问题进行了讨论     

基于假设检验的地震动强度(烈度)速报方法

地震发生后数分钟内,快速、可靠地判别出地震动强度(烈度)的空间分布,用以估计不同地区的受灾程度,可以为政府开展应急救援并合理分配救援力量提供决策依据,保证救援人员及时、准确地到达极震区并展开搜救,以减少生命财产损失。本文基于统计学中的假设检验方法,对历史震害资料进行统计,提出了一种利用强地震动参数判别地震动强度(烈度)的方法。比较结果表明,本方法所确定的地震动强度(烈度)与实际震害烈度对应较好,能较真实地反映实际震害情况。     

自适应非局部均值地震随机噪声压制(英文)

非局部均值滤波是一种基于图像信息冗余的去噪方法,其认为图像自身的有效结构具有一定的重复性,而随机噪声则不具备这一特点,通过利用图像本身的自相似性来达到压制随机噪声的目的,是一种全局的去噪方法。本文把这一思想引入地震数据随机噪声压制中,针对传统非局部均值滤波计算量过大的问题,文章采用分块非局部均值的方式来减少计算量;针对滤波参数选取会影响非局部均值滤波效果的问题,提出一种简单的自适应滤波参数地震数据分块非局部均值算法。模型和实际数据处理结果表明:相对于传统的去噪算法(如f-x反褶积),该方法在压制随机噪声的同时对有效信号保护地更好,具有更高的保真度,更有利于后续的处理和解释工作。     

Moment Magnitude and Its Calculation

In this paper, we give a brief introduction to the proposal and development history of the earthquake magnitude concept. Moment magnitude M_W is the best physical quantity for measuring earthquakes. Compared with other magnitude scales used traditionally, moment magnitude is not saturated for all earthquakes, regardless of big and small earthquakes, deep and shallow earthquakes, far field and near field seismic data, geodetic and geological data, moment magnitude can be measured, and can be connected with well-known magnitude scales such as surface wave magnitude M_S. Moment magnitude is a uniform magnitude scale, which is suitable for statistics with wide magnitude range. Moment magnitude is the preferred magnitude selected by the International Seismological community, and it is preferred by the departments responsible for publishing seismic information to the public.Moment magnitude is a uniform magnitude scale, which is suitable for statistics with wide magnitude range. Moment magnitude is a preferred magnitude for international seismology, it is preferred by the agency responsible for providing information about earthquakes to the public. We provide all formulas used in the calculation of moment magnitude, and the calculation steps in detail. We also analyzed some problems and rules to solve these problems by using different formulas and numerical value calculation steps.     

SIGNAL-TO-NOISE RATIO ENHANCEMENT IN MULTICHANNEL SEISMIC DATA VIA THE KARHUNEN-LOÉVE TRANSFORM*

The Karhunen-Loéve transform, which optimally extracts coherent information from multichannel input data in a least-squares sense, is used for two specific problems in seismic data processing. The first is the enhancement of stacked seismic sections by a reconstruction procedure which increases the signal-to-noise ratio by removing from the data that information which is incoherent trace-to-trace. The technique is demonstrated on synthetic data examples and works well on real data. The Karhunen-Loéve transform is useful for data compression for the transmission and storage of stacked seismic data. The second problem is the suppression of multiples in CMP or CDP gathers. After moveout correction with the velocity associated with the multiples, the gather is reconstructed using the Karhunen-Loéve procedure, and the information associated with the multiples omitted. Examples of this technique for synthetic and real data are presented.     

预测多次波的逆散射级数方法与SRME方法及比较

逆散射级数方法和SRME方法是典型的两类基于波动方程的无需地下结构信息的自由表面多次波预测方法,本文详细讨论了这两类方法的基本思想、方法原理和实现思路,并对2维逆散射级数方法进行了降维简化,推导给出了1.5维逆散射级数衰减自由表面多次波的方法,减少了计算量,并降低了对3维规则观测系统的要求.利用经典SMAART模型数据测试比较了2维逆散射级数方法、1.5维逆散射级数方法及2维SRME方法预测自由表面多次波的效果及优缺点,比较了三者在方法实现、并行计算效率及对数据要求上的异同,并结合分析比较结果,给出了实际应用中方法选择的建议.     

Reconstruction of the layer anisotropic elastic parameters and high-resolution fracture characterization from P-wave data: a case study using seismic inversion and Bayesian rock physics parameter estimation

Wide-azimuth seismic data can be used to derive anisotropic parameters on the subsurface by observing variation in subsurface seismic response along different azimuths. Layer-based high-resolution estimates of components of the subsurface anisotropic elastic tensor can be reconstructed by using wide-azimuth P-wave data by combining the kinematic information derived from anisotropic velocity analysis with dynamic information obtained from amplitude versus angle and azimuth analysis of wide-azimuth seismic data. Interval P-impedance, S-impedance and anisotropic parameters associated with anisotropic fracture media are being reconstructed using linearized analysis assuming horizontal transverse anisotropy symmetry. In this paper it is shown how additional assumptions, such as the rock model, can be used to reduce the degrees of freedom in the estimation problem and recover all five anisotropic parameters. Because the use of a rock model is needed, the derived elastic parameters are consistent with the rock model and are used to infer fractured rock properties using stochastic rock physics inversion. The inversion is based on stochastic rock physics modelling and maximum a posteriori estimate of both porosity and crack density parameters associated with the observed elastic parameters derived from both velocity and amplitude versus angle and azimuth analysis. While the focus of this study is on the use of P-wave reflection data, we also show how additional information such as shear wave splitting and/or anisotropic well log data can reduce the assumptions needed to derive elastic parameter and rock properties.     

高阶谱混合方法地震子波估计及处理

凭借高阶累积量对噪声的不敏感性,依据地震记录高阶谱中包含的子波相位、幅值信息,提出了基于双谱和三谱混合的子波恢复方法,并对理论合成记录进行子波估计及处理模拟试验,其结果论证了该方法的可行性.同时,用本文介绍的方法对野外采集的地震资料进行处理后,其分辨率明显提高,说明了高阶谱技术在资料处理方面有相当大的潜力.     

地震资料振幅保持影响因素分析

地震资料的振幅信息是数据处理和解释的一个重要参数,储层的岩性研究要求对振幅信息进行更精确的处理,地震资料的保幅性具有重要的意义.影响地震资料振幅保持的因素很多,其中采集和处理过程中对振幅的影响最为直接、广泛.根据实际资料处理情况,文章重点分析了数据采集和资料处理对振幅因素的制约,从属性研究和技术层面上探讨实际生产中应避免或解决的问题.     

随机地震反演关键参数优选和效果分析(英文)

随机地震反演技术是将地质统计理论和地震反演相结合的反演方法,它将地震资料、测井资料和地质统计学信息融合为地下模型的后验概率分布,利用马尔科夫链蒙特卡洛(MCMC)方法对该后验概率分布采样,通过综合分析多个采样结果来研究后验概率分布的性质,进而认识地下情况。本文首先介绍了随机地震反演的原理,然后对影响随机地震反演效果的四个关键参数,即地震资料信噪比、变差函数、后验概率分布的样本个数和井网密度进行分析并给出其优化原则。资料分析表明地震资料信噪比控制地震资料和地质统计规律对反演结果的约束程度,变差函数影响反演结果的平滑程度,后验概率分布的样本个数决定样本统计特征的可靠性,而参与反演的井网密度则影响反演的不确定性。最后通过对比试验工区随机地震反演和基于模型的确定性地震反演结果,指出随机地震反演可以给出更符合地下实际情况的模型。     

非重复采集时移地震正演模拟及可行性分析

本文主要研究前期为常规三维地震勘探和后期为高精度三维地震勘探的这种典型非重复采集时移地震的可行性,主要使用正演模拟和匹配处理相结合的方法进行.本文推导了基于PML边界的三维声波波动方程时空域高阶有限差分正演方程,根据岩石物理流体替代分析方法计算得到时移前后储层的弹性参数,建立了时移地震地球物理模型,设计了常规三维和高精度三维观测系统,进行地震正演模拟,获得了非重复采集时移地震理论模拟数据.利用匹配处理法对非重复采集时移地震正演模拟数据和实际资料进行可行性分析,匹配处理过程主要包括初始数据匹配、一致性处理和互均化处理等.理论模拟数据和实际资料的匹配处理结果表明,通过针对性的分析和处理,利用非重复采集的地震资料进行时移地震研究是可行的,能够得到较好的时移地震响应,在一定程度上反映了油藏的变化情况.     

自适应VMD的地震资料高分辨率处理方法研究

随着勘探开发的不断深入,常规地震资料受分辨率的限制难以满足精细勘探开发的需求.由于地震信号不同频率成分的衰减程度不同,故可结合分频技术对各频率成分进行差异化补偿,进而提高地震资料分辨率.而常规分频技术普遍分频精度不高,存在模态混叠现象,不能较好地适用于地震资料处理.针对上述问题,本文提出基于自适应变分模态分解(VMD)...     

基于模糊粗糙集的机器学习储层参数预测

因为地震数据的三维空间分布优势,地震属性已经被广泛应用于含油气性预测、储层厚度预测、孔隙度预测等。但也存在地震属性之间信息冗余、属性与储层物性参数关系模糊的问题。针对这两个问题,将模糊粗糙理论和机器学习引入到储层参数预测中来。通过模糊粗糙集理论对地震属性进行约简,去除冗余信息,得到最优化的地震属性组合;将约简后的属性作为机器学习的输入,实现从地震属性到储层物性参数的非线性映射。该方法既保留了地震属性中有效信息,又避免了因输入变量过多而导致的网络模型训练困难。实际数据应用表明,属性约简的机器学习预测结果分辨率更高,并与数据吻合更好。      

Onshore and offshore seismic and lithostratigraphic analysis of a deeply incised Quaternary buried valley system in the Northern Netherlands

High-resolution seismic data (onshore and offshore), geophysical borehole data as well as detailed lithofacies from airlift boreholes were acquired in northern Netherlands on and around the island of Ameland. Marine and land seismic data combined with information from land boreholes have been explored with the objective of providing a sedimentary model. Qualitative seismic facies analysis of the valley fill commonly shows a thin unit with high amplitude reflectors at the base. Thick units of variable seismic facies (transparent to high amplitude) occur higher up in the sequence. Onlap is common at mid–upper levels within the sandy valley fill (with clay in mm layering), and a transparent seismic facies, corresponding to firm clays, is common at the top. Almost all lithological unit boundaries recognised within core parameters correspond with seismic unconformities within error margins. Subunits contain multiple cyclical trends in gamma ray and grain size. Cyclical trends show lower order fluctuations in gamma radiation on a scale of less than 1 m. Gamma-ray pattern variability between units, e.g. in general coarsening-up or fining-up units, suggests migration of subaqueous outwash fans or ice margin fluctuations. Seismic results could support a headward excavation and backfilling process suggested by Praeg [Morphology, stratigraphy and genesis of buried Elsterian tunnel valleys in the southern North Sea basin [PhD thesis]: University of Edinburgh, 207 pp.; Journal of Applied Geophysics, (this volume)] as being responsible for the formation of buried valleys. On a lithological scale, a more complicated, detailed and cyclical pattern arises. Catastrophic processes are considered unlikely as being responsible for the infill sequence because of the observed small-scale facies variability and because of the presence of diamicton layers. Diamicton layers at the base of basal unconformities as well as higher in sequence could suggest subglacial deformation by grounded ice before and during the valley-fill process.     

Near-surface velocity model construction based on a Monte-Carlo scheme

In tomographic statics seismic data processing, it is crucial to determine an optimum base for a near-surface model. In this paper, we consider near-surface model base determination as a global optimum problem. Given information from uphole shooting and the first-arrival times from a surface seismic survey, we present a near-surface velocity model construction method based on a Monte-Carlo sampling scheme using a layered equivalent medium assumption. Compared with traditional least-squares first-arrival tomography, this scheme can delineate a clearer, weathering-layer base, resulting in a better implementation of datuming correction. Examples using synthetic and field data are used to demonstrate the effectiveness of the proposed scheme.     

PREDICTING ABNORMALLY PRESSURED SEDIMENTARY ROCKS*

Modern seismic processing techniques developed in recent years have provided the explorationist with more meaningful data than would have been predicted even by optimists. Correct migration of seismic data, relative amplitude preservation of reflections, and seismic trace inversion represent the necessary efforts to ensure that the best possible picture of in situ physical properties of the subsurface section is revealed. Moreover, compacted and over-pressured zones can be predicted from surface data prior to drilling a well through them. The basic tool for predicting overpressured zones from the surface is still the velocity analysis derived from good reflection data with few erratic multiples. The extraction of regional normal compaction trends from the seismic velocities allows one—where velocities deviate from the trend—to locate the top of overpressure. Moreover, the statistical behavior of the ratios of the sonic log vs pore pressure in existing boreholes enables one to convert the deviation from the trend of the seismic velocities into overpressure rates expected at the seismic reflection horizon. This paper presents a field case study showing how the knowledge of well site lithology together with the more detailed information extracted from inverted seismic data enables the prediction to match well conditions with high reliability.     

Research on seismic fluid identification driven by rock physics

Seismic fluid identification works as an effective approach to characterize the fluid feature and distribution of the reservoir underground with seismic data. Rock physics which builds bridge between the elastic parameters and reservoir parameters sets the foundation of seismic fluid identification, which is also a hot topic on the study of quantitative characterization of oil/gas reservoirs. Study on seismic fluid identification driven by rock physics has proved to be rewarding in recognizing the fluid feature and distributed regularity of the oil/gas reservoirs. This paper summarizes the key scientific problems immersed in seismic fluid identification, and emphatically reviews the main progress of seismic fluid identification driven by rock physics domestic and overseas, as well as discusses the opportunities, challenges and future research direction related to seismic fluid identification. Theoretical study and practical application indicate that we should incorporate rock physics, numerical simulation, seismic data processing and seismic inversion together to enhance the precision of seismic fluid identification.