鄂尔多斯盆地南部黄土塬区地震资料处理与解释 第二部分:地震资料解释

鄂尔多斯盆地南部的黄土高原,由于长期 风化、侵蚀,形成了树枝状水系与沟、塬、梁、峁、 坡并存的独特黄土地貌。针对这种复杂地表条件长 庆物探已建立了沿沟弯线为主、辅以黄土塬多线和 网状三维的采集方法;确立了高精度静校正、适度 去噪、共反射面元优化及已知井反射系数序列控制 的高保真处理方法、本文着重介绍处理、解释二大 环节的关键方法及应用效果。     

鄂尔多斯盆地南部的黄土塬区地震资料处理与解释,第一部分:地震资料处理(英文)

鄂尔多斯盆地南部的黄土高原,由于长期 风化、侵蚀,形成了树枝状水系与沟、塬、梁、峁、 坡并存的独特黄土地貌。针对这种复杂地表条件长 庆物探已建立了沿沟弯线为主、辅以黄土塬多线和 网状三维的采集方法;确立了高精度静校正、适度 去噪、共反射面元优化及已知井反射系数序列控制 的高保真处理方法、本文着重介绍处理、解释二大 环节的关键方法及应用效果。     

鄂尔多斯盆地黄土山地地震资料采集技术

鄂尔多斯盆地黄土山地区和巨厚黄土沙漠区因其特有的地震地质特征,高分辨率岩性地震勘探面临着许多难题。90年代中期以来,针对不同地表条件、不同地质目标,经过多年的科研攻关,形成了三种采集系列技术:沟中弯线高分辨率采集技术、多直线高分辨率采集技术、三维采集技术,并进行了工业化生产,获得了高信噪比、高分辨率、高保真度的地震资料,取得了显著的经济和社会效益。     

昆明盆地基底断裂地震勘探测线设计及施工参数试验分析

为了对昆明市活断层构造的深浅关系有更深入的了解,在浅层地震反射勘探的基础上,布设了一条东西向、横跨昆明盆地的中深层探测剖面KM4测线,通过对测线参数的试验与分析,确定了适合昆明盆地反射地震勘探的施工参数,采用该施工参数,开展了有效勘探深度为2～3 km的中深层反射地震勘探,确定了目标区隐伏活断层在盆地深部与盆地基底展布的异同及空间关系,探测到了昆明盆地深部断层的基本位置,确定了浅部断层与盆地基底断裂间的关系.对该测线的设计和参数采集试验分析,为城市和山区的活断层探测提供了宝贵的经验.     

四川盆地及其西部边缘震区基底磁性界面与地震的研究

在对四川盆地及其西部边缘震区航磁资料进行分析研究的基础上，依据频率域磁性单界面反演方法对航磁异常进行了数据处理，求取了基底磁性界面的定量埋深，结合区域构造特征，地热分布及板块运动对地震的孕育环境进行了综合研究和讨论。     

上海地震台阵数据处理及其在地震研究中的进展

地震台阵是在与所观测地震波波长相当的孔径范围内有规则排列安装若干地震计的地震观测系统,它采用独特的地震数据处理方法,将各子台的数据会聚在一起,抑制地面噪声,提高信噪比并获取有关震源及地球内部结构的信息,从而获得比单个地震台更强的地震监测能力,特别是提取微弱地震信号的能力.同时,由于地下介质普遍为各向异性的,利用地震台阵可以研究地球内部介质的各向异性并为地球动力学提供有效的数据质量保证.目前地震台阵已成为全球地震监测网的重要部分,是一种先进的地震观测技术.应用地震台阵可监测较远处的微震事件,因而有利于对那些不宜于正当地架设台站的地区进行地震监测,特别是近海海域地区的地震监测.     

最优小波基选择法在测震数据干扰处理中的研究与应用

选取成都地震台的测震数据作为研究样本,将不同的小波基进行了以重构精度、相对SNR值以及去噪后频谱的分析结果为依据的筛选流程。结果显示:bior2.4小波基重构精度最佳、去噪效果良好、更加完整地保留了样本的有效高频信号,是适合成都地震台测震数据的最优小波基。将其应用于成都地震台的测震数据干扰处理,波形去噪效果明显,波形的信噪比得到明显提高,对震级计算并无显著影响。     

小波分析法在海拉尔地震台前兆数据处理中的应用研究

应用小波变换法可对不同频率成分进行分解的特性,选取d b4小波基函数,尺度为1～8阶,对海拉尔地震台前兆资料进行分析研究.结果表明,应用小波变换方法可较容易地识别和剔除气压、场地环境干扰等影响海拉尔地震台伸缩仪观测资料精度的诸多因素,气压和场地环境干扰在小波细节分解d3～d6部分异常显著;小波变换法对同震效应的识别、提...     

Estimation of Dry Fracture Weakness,Porosity, and Fluid Modulus Using Observable Seismic Reflection Data in a Gas-Bearing Reservoir

Fracture detection and fluid identification are important tasks for a fractured reservoir characterization. Our goal is to demonstrate a direct approach to utilize azimuthal seismic data to estimate fluid bulk modulus, porosity, and dry fracture weaknesses, which decreases the uncertainty of fluid identification. Combining Gassmann’s (Vier. der Natur. Gesellschaft Zürich 96:1–23, 1951) equations and linear-slip model, we first establish new simplified expressions of stiffness parameters for a gas-bearing saturated fractured rock with low porosity and small fracture density, and then we derive a novel PP-wave reflection coefficient in terms of dry background rock properties (P-wave and S-wave moduli, and density), fracture (dry fracture weaknesses), porosity, and fluid (fluid bulk modulus). A Bayesian Markov chain Monte Carlo nonlinear inversion method is proposed to estimate fluid bulk modulus, porosity, and fracture weaknesses directly from azimuthal seismic data. The inversion method yields reasonable estimates in the case of synthetic data containing a moderate noise and stable results on real data.     

Interpretation of Gravity and Gamma-Ray Spectrometry Data in Low Temperature Hydrothermal Systems,Southeastern Part of Fukuoka,Japan

The Hakata hot springs area is located in Fukuoka City, which is in the southwestern part of Japan. Gamma-ray and gravity surveys were conducted to understand the relationship between the low-temperature hydrothermal systems and geophysical data of the area. The depth of the reservoir basement, which was derived from gravity data, gradually deepens toward the east; it includes some steep depth gradients in the Hakata hot springs area. High intensities of gamma-rays were detected around these gradients. In addition, higher hot spring temperatures and flow rates can be observed in this area. These results indicate that some part of the level of the basement where the hot springs are concentrated is a part of the Kego Fault and is similar to the fracture zone created by past activities of the fault. Moreover, these steep depth gradients act as a path for hot spring water from the deeper side of the granitic body to the surface.     

鄂尔多斯盆地南部的黄土塬区地震资料处理与解释,第一部分:地震资料处理

Branching river channels and the coexistence of valleys, ridges, hiils, and slopes＇as the result of long-term weathering and erosion form the unique loess topography. The Changqing Geophysical Company, working in these complex conditions, has established a suite of technologies for high-fidelity processing and fine interpretation of seismic data. This article introduces the processes involved in the data processing and interpretation and illustrates the results.     

测震台址勘选数据处理辅助程序设计与应用

针对测震台址勘选中数据处理的重要性和计算结果的真实性,避免在数据处理过程中因手工分析计算出现错误,通过深入分析手工计算流程,设计编写了一套辅助控制程序,配合EDSP-IAS和地噪声处理软件,实现勘选数据处理流程的自动运行与管理,避免因人为因素出现差错,为台址勘选实测地噪声值数据批处理提供便捷。该辅助程序可用于烈度速报新建台址勘选数据批处理工作。     

Analysis of Tectonic Conditions for Strong Earthquakes and Prediction of Seismic Risk of Seismogenic Fault Zones in the Northern Part of North China

The tectonic conditions for strong earthquakes are complicated in various aspects.The genetic conditions for strong earthquakes were studied from the angle of various disciplines.About 20 conditions belonging to different fields have been described by predecessors.In this paper,the authors try to study and evaluate all the tectonic condition factors for strong earthquakes by the methods of fuzzy mathematics and hierarchical analysis.Taking the northern part of North China as an example,the authors make a comprehensive digital analysis of all the quantitative and semi-quantitative tectonic factors.The credibility values of all strong earthquakes with different magnitudes are given after statistical analysis and calculation.Forty-one fault zones in the study region are quantitatively analyzed,and the potential seismogenic fault zones,maximum magnitude,and risk of earthquake occurrence in the near future are assessed.The result of synthetic evaluation,based on all tectonic conditions of different categorie     

地震资料宽频处理技术在天然气水合物矿体描述中的应用研究

针对天然气水合物钻探难以有效解决的矿体空间展布等难点,提出一套基于自适应鬼波压制技术的地震宽频处理技术,有效改善资料分辨率。首先采用上下行波场分离的鬼波压制技术实现对震源端和电缆端鬼波的压制;然后通过高精度网格层析反演速度建模技术获取高质量速度场,利用叠前深度偏移成像进一步提高水合物层成像精度。实践表明,相对于常规处理而言,宽频处理的水合物地震特征更清晰,细节信息更丰富,有利于天然气水合物矿体的准确描述。     

山西临汾盆地及其周缘现今地震活动特征与地震危险性分析

依据地震地质构造和断裂带几何特征,将临汾盆地及其周缘划分为6个研究区域,运用近27年经过精确定位的区域台网地震资料,采用多个地震活动参数值的组合,结合震源深度分布、历史强震背景,分析临汾盆地及其周缘各研究区的现今活动状态。结果表明,现今应力水平较高的3个区域分别为洪洞—临汾凹陷、侯马凹陷和峨眉台地。其中,洪洞—临汾凹陷为1303年洪洞8.0级地震的破裂区,现今应力水平仍然较高,其中深部出现的小震活动稀疏段可能表明其正处于破裂区的恢复阶段;侯马凹陷至峨嵋台地北缘自有史料记载以来,没有记录到M6以上地震,现今地震活动特征显示其处于较高应力水平下的相对闭锁状态,属于未来强震的危险区段;灵石隆起、辛置凸起和襄汾凸起现今应力水平相对较低,以中小地震活动为主要特征,强震危险性较小。     

时序数据库在海量地震波形数据分布式存储与处理中的应用初探

通过分析时序数据库的技术特点和海量地震数据存储和处理的需求,设计和实现了基于时序数据库的地震波形数据存储和处理系统。经过开发、测试和应用比较,新的地震时序数据库系统具有高可用、实时存储吞吐量大、历史数据压缩率高、分布式处理速度快等优势,能够较好地解决地震波形数据体量激增带来的存储和处理困难问题。     

Sedimentation in the floodplains of the Mekong Delta,Vietnam Part II: deposition and erosion

Deposition and erosion play a key role in the determination of the sediment budget of a river basin, as well as for floodplain sedimentation. Floodplain sedimentation, in turn, is a relevant factor for the design of flood protection measures, productivity of agro‐ecosystems, and for ecological rehabilitation plans. In the Mekong Delta, erosion and deposition are important factors for geomorphological processes like the compensation of deltaic subsidence as well as for agricultural productivity. Floodplain deposition is also counteracting the increasing climate change induced hazard by sea level rise in the delta. Despite this importance, a sediment database of the Mekong Delta is lacking, and the knowledge about erosion and deposition processes is limited. In the Vietnamese part of the Delta, the annually flooded natural floodplains have been replaced by a dense system of channels, dikes, paddy fields, and aquaculture ponds, resulting in floodplain compartments protected by ring dikes. The agricultural productivity depends on the sediment and associated nutrient input to the floodplains by the annual floods. However, no quantitative information regarding their sediment trapping efficiency has been reported yet. The present study investigates deposition and erosion based on intensive field measurements in three consecutive years (2008, 2009, and 2010). Optical backscatter sensors are used in combination with sediment traps for interpreting deposition and erosion processes in different locations. In our study area, the mean calculated deposition rate is 6.86 kg/m² (≈ 6 mm/year). The key parameters for calculating erosion and deposition are estimated, i.e. the critical bed shear stress for deposition and erosion and the surface constant erosion rate. The bulk of the floodplain sediment deposition is found to occur during the initial stage of floodplain inundation. This finding has direct implications on the operation of sluice gates in order to optimize sediment input and distribution in the floodplains. Copyright © 2013 John Wiley & Sons, Ltd.