松辽盆地北部扶杨油层河道砂体的地震识别方法研究

应用地震技术预测和识别扶杨油层河道砂体是当前松辽盆地北部的油气勘探中最为急需的技术之一。本文以GTZ地区为例,探讨了扶杨油层河道砂体的成因特点,指出地震的低分辨率,河道砂体的薄互层、横向变化快、储层非均质性强等地质特点,是当前应用地震技术识别扶杨油层河道砂体的困难所在。文中介绍了当前技术条件下河道识别的两种方法:利用频谱成像技术和叠前方位各向异性技术进行河道识别的方法和思路。以扶余油层为目的层说明了应用上述两种方法识别河道砂体的良好效果,并和已知井资料进行对比,符合率可达80%。     

六安地震台DPDC-2低频电磁扰动仪映震能力

描述六安市地震台DPDC-2低频电磁扰动仪观测原理及运行环境,以2014年金寨震群、2015年3月14日安徽省阜阳市4.3级地震和2015年2月14日中国台湾台东县6.2级地震为例,分析该台电磁扰动仪映震能力。结果发现,六安地震台DPDC-2低频电磁观测扰动仪对金寨震群及阜阳M_S 4.3地震有一定映震能力,对国内6.5级以下远震未表现出较强的映震能力。     

CROSS-BOREHOLE OBSERVATION OF MODE CONVERSION FROM BOREHOLE STONELEY WAVES TO CHANNEL WAVES AT A COAL LAYER1

Conversion of borehole Stoneley waves to channel waves was observed in data from a seismic cross-borehole experiment conducted between wellbores penetrating a thin coal layer at 2022 m depth, near Rifle, Colorado. Traveltime moveout observations show that borehole Stoneley waves underwent partial conversion to channel waves at the coal layer. The channel waves were detected directly in an adjacent borehole 35 m away at receiver positions within the coal. Stoneley waves, subsequently produced by partial conversion of channel waves, were also detected at receiver positions located up to 50 m above and below the coal layer in the adjacent borehole. We infer the channel wave to be the first-higher Rayleigh mode by comparing the observed group velocity with theoretically derived dispersion curves. Identifying the conversion between borehole and stratigraphically guided waves is significant because coal penetrated by multiple wells may be detected without placing a transmitter or receiver in the coal itself.     

On the Relationship Between the Crustal Strain Rate and Seismicity:Detect the Source-Field Relation from the Crustal Strain Field

The relationship between the strain cumulative rate (i.e., the crustal strain rate, or CSR in short) and seismic activity is analyzed to develop a new method to determine risky regions for strong shocks within recent years by the recorded crustal strain field. Seismic activity, especially the recurrence period, is different in different areas. Ding Guoyu (1984) pointed out that, for different seismic regions, the difference in the recurrence period of strong earthquakes is mainly controlled by their difference in the rate of the tectonic movement, which is controlled by the seismogenic environment and the tectonic conditions. The method of determining the risky regions for strong shocks from the gradient of vertical strain rates observed in a geodetic survey is preliminarily tested with the earthquakes in recent years; the results show that this method is effective and useful for earthquake prediction. The relationship between CSR and seismicity in a specific region is studied with strain theories, obse     

APPLICATION OF STABLE OXYGEN AND HYDROGEN ISOTOPES TO THE VERIFICATION OF GROUNDWATER ANOMALIES

Identifying the source of the observed fluid anomalies is a major tast in verifying the anomalies in seismic subsurface fluid research. The stable hydrogen and oxygen isotopes are proved to be effective to trace the underground fluid origin and its development. In this study, we summarized the basic principles, water sampling and testing techniques in recognizing the fluid anomalies by using the stable hydrogen and oxygen isotopes. We also enumerated the related applications in analyzing the sudden water level increase and the rapid shifting from limpid water to murky. The stable hydrogen and oxygen isotopes analysis can be used to verify the macroscopic underground fluid anomalies, such as subsurface water temperature, water level and chemical component changes, and the wide use of this method in seismic subsurface fluid research will be helpful to identify the tectonic or non-tectonic related influencing factors to the fluid anomalies.     

无井条件下建立碎屑岩储层地震地质模型研究

常规的储层建模以井数据为基础,建立孔隙度、渗透率和含油饱和度等储层属性参数模型,并通过油田开发生产数据进行拟合,得到最佳地质模型.在南海西北部深水区无井控制的情况下,针对中央峡谷浊积水道储层,采用确定性建模与连续型随机建模相结合的方法,建立碎屑岩储层地震地质模型,应用地震正演模拟和相似性分析方法,确定浊积水道砂体最佳模拟参数.文章首先分析了碎屑岩储层特征,应用连续型随机建模的方法模拟储层空间分布.然后分析实际地震、地质资料,应用层序地层学思想,对研究区划分沉积体系域,建立层序地层格架;基于波阻抗和多种地震属性,采用人机交互的方法对浊积水道储层框架结构进行精细解释,建立储层结构模型;将储层结构模型与砂泥互层随机介质进行"交"、"并"运算,利用连续型随机模拟方法对储层内部介质进行精细刻画,建立中央峡谷浊积水道随机介质储层模型;通过对模型正演模拟、常规处理和相似性分析等建立最佳储层模型.文章研究了在无井条件下建立储层地震地质模型的方法,揭示南海西北部深水区中央峡谷浊积水道储层的空间展布和内部结构特征.     

Tracking modal parameters from building seismic response data using recursive subspace identification algorithm

Tracking modal parameters and estimating the current structural state of a building from seismic response measurements, particularly during strong earthquake excitations, can provide useful information for building safety assessment and the adaptive control of a structure. Therefore, online or recursive identification techniques need to be developed and implemented for building seismic response monitoring. This paper develops and examines different methods to track modal parameters from building seismic response data. The methods include recursive data‐driven subspace identification (RSI‐DATA) using Givens rotation algorithm, and RSI‐DATA using Bona fide algorithm. The question on how well the results of RSI‐DATA reflect the real condition is investigated and verified with a bilinear SDOF simulation study. Time‐varying modal parameters of a four‐story reinforced concrete school building are identified based on a series of earthquake excitations, including several seismic events, large and small. Discussions on the different methods' ability to track the time‐varying modal parameters are presented. The variation of the identified building modal frequencies and damping ratios from a series of event‐by‐event seismic responses, particularly before and after retrofitting of the building is also discussed. Copyright © 2017 John Wiley & Sons, Ltd.     

浅层地震勘探在沿海地区隐伏断层探测中的应用

中国沿海地区的第四系厚度变化较大,在大部分地区存在淤泥、黏土和砂层的多重互层情况,这种地层结构对地震波的传播十分不利,容易造成对高频信号能量的强烈耗散。沿海地区又具有人口密度大、工业干扰强烈的特点,地震波的激发、接收条件较差。文中给出了在粤东、天津和唐山覆盖层厚度变化较大的地区,利用浅层地震勘探开展隐伏断层探测的应用实例。较系统地介绍了野外工作、资料处理和解释方法。阐述了在强干扰环境下提高信噪比和分辨率的有效技术途径。所给实例中的反射波组能量强,隐伏断层的反应明显,经跨断点钻探验证,结果证实地震勘探确定的界面深度、断点位置和基岩错距等参数都是可靠的。所述技术方法对类似地区的城市活断层探测和工程物探工作都有较重要的参考价值     

The Best Combination Methods and Applied Research of Seismic Prospecting for Active Faults in Urban Areas

This paper introduces briefly the basic principles of various seismic prospecting techniques and working methods according to nationwide practices of seismic prospecting of active faults beneath big cities in recent years.Furthermore,it analyzes the application range of different seismic prospecting methods,main achievements and solved problems,and discusses the best combination of seismic exploration methods for detecting crustal structures and locating the faults used in the present stage,that is,to trace faults which are at depths of hundred of meters underground using shallow seismic investigation,to detect the faults which are above basement(at a depth of kilometers) using high resolution refraction sounding,and the deep crustal faults using combined seismic prospecting methods of reflection seismic sounding and wide-angle reflection/refraction sounding,and furthermore,to use the 3-D deep seismic sounding method to obtain 3-D velocity structures beneath urban areas.Thus,we can get information about fault attitude and distribution at different depths and a complete image of faults from their shallow part to deep part using the combined seismic exploration method.Some application examples are presented in the article.     

Improving reservoir thickness prediction using seismic attributes and attributes fusion

Usage of any single attribute would introduce unacceptable uncertainty due to limited reservoir thickness and distribution, and strong lateral variations in lithological traps. In this paper, a wide range of prestack and post-stack seismic attributes is utilized to identify a range of properties of turbidity channel sandstone reservoir in Block L118 of J Oilfield, China. In order to better characterize the turbidity channel and lower the uncertainty, we applied multi-attribute fusion to weight a variety of seismic attributes in terms of their relevance to the identification of turbidity channel reservoir. Turbidity channel boundary is clearly present in the new attribute and the reservoir thickness prediction is improved. Additionally, fluid potential of reservoir was predicted using this fused attribute with a high value anomaly indicating high fluid potential. The multi-attribute fusion is a valid approach for the fine prediction of lithologic reservoirs, reducing the risks typically associated with exploration.     

Sensitivity of seismic structural response to interpretation of soils data

This paper investigates the sensitivity of the predicted seismic response of buildings in a PWR nuclear power station to the potential changes in the techniques and methods of interpreting soil data that have occurred over the last decade. The investigation is based on the soil-structure interaction (SSI) response of a typical PWR reactor building on a soft site during a seismic event. The current techniques and methods of interpretation of soils data tend to lead to a stiffer site with lower soil material damping than the earlier techniques. This leads to an increase in the SSI natural frequencies of typical buildings and an increase in its seismic response. This increase in the seismic response could put into question any seismic design based on seismic loads derived using the previously accepted generic soil data. The paper concludes with a recommendation for further consideration of the proposed departure from the previously accepted soil data.     

基于频率域峰值属性的河道砂体定量预测及应用(英文)

河道砂体是陆相含油气盆地最重要的储集类型之一,其边界识别和厚度定量预测是储层预测的热点难题。本文在总结现有方法技术的基础上,提出一种利用频率域峰值属性进行河道砂体边界识别和厚度定量预测的新方法。对典型河道薄砂体地震反射进行了正演模拟,构造了一种新的地震属性——峰值频率-振幅比,研究表明:峰值频率属性对地层厚度变化敏感,振幅属性对地层岩性变化敏感,两者比值突出河道砂体的边界,同时,借助峰值频率与薄层厚度间存在的定量关系进行薄砂体厚度计算。实际数据应用表明,地震峰值频率属性可以较好的刻画河道的平面展布特征;峰值频率-振幅比属性可以提高对河道砂体边界的识别能力;利用频率域地震属性进行砂体边界识别及厚度定量预测是可行的。     

地震槽波的数学-物理模拟初探

针对地震槽波在低速层的传播特性,开展了煤层内地震槽波勘探的数值模拟和物理模拟研究的初探工作.在数值模拟研究方面,采用交错网格有限差分法对煤层中的地震槽波进行三分量全波场模拟.基于波场快照和人工合成地震记录研究了不同模型中的波场特征和各种波型的传播规律.在物理模拟方面,通过选用不同配比的环氧树脂和硅橡胶类材料构建地震槽波物理模型,利用透射法和反射法观测系统获得了清晰的地震槽波记录以研究槽波的地震学特征.研究表明,在煤层内槽波的地震波场中,Love型槽波的能量小于Rayleigh型槽波的SV分量,大于Rayleigh型槽波的SH分量.相对于Love型槽波和Rayleigh型槽波的SH分量,Rayleigh型槽波的SV分量在围岩中的泄露能量较强.在煤层界面附近的围岩中,地震波仍以槽波形式传播,随着距离的增加能量逐渐衰减.随着煤层变薄,煤层槽波主频向高频方向移动,频散现象增强,传播速度增大.     

Advanced three-dimensional seismic imaging of deep supercritical geothermal rocks in Southern Tuscany

The seismic K-Horizon is the key to gaining understanding on the deep supercritical geothermal rocks in Southern Tuscany. The K-Horizon is hosted in metamorphic rocks, which cause strong seismic wavefield scattering resulting in a poor signal-to-noise ratio. Our study aims to reveal high-resolution seismic images of the K-Horizon below a geothermal field in Southern Tuscany, using an advanced three-dimensional seismic depth imaging approach. The key seismic pre-processing steps in the time domain include muting a large amount of persistent noise based on the statistical analysis of the seismic amplitudes, and tomostatics technique to correct for static effects. We carried out seismic depth imaging using Kirchhoff Pre-Stack Depth Migration and Fresnel Volume Migration techniques. Each migration technique was tested with constant and heterogeneous three-dimensional velocity models. Due to the difficulties in determining emergent angles for this low signal-to-noise ratio data set, the migration results with the heterogeneous three-dimensional velocity model show less coherent reflections compared to the migration results using the constant velocity model. Both velocity models however lead to relatively the same structure and depth of the K-Horizon, indicating the similarity of the average velocities along the wave propagation paths in both velocity models. With both velocity models Fresnel Volume Migration yields the K-Horizon with better reflection coherency and higher signal-to-noise ratio than standard Kirchhoff Pre-Stack Depth Migration. Nevertheless, both migration techniques have been able to reveal the K-Horizon with relatively high resolution and provide a reliable basis for geothermal rock characterization as well as steering of the first geothermal well penetrating the K-Horizon.     

南海北部白云凹陷深水油气区的重-震数据处理与分析

白云凹陷位于南海北部陆缘深水地带,是我国深水油气资源勘探的重要地区。开展重-震成像研究,是分析该区烃源岩分布特征、大型构造圈闭、成藏层系与储层条件的重要方法。本文通过重力异常、地震Vs波速结构模型及地震勘探剖面分析,获得研究区自由空间重力异常、布格重力异常、水平和垂向梯度、密度反演图像、Vs波速度结构图像以及高分辨率地震勘探剖面图像。重力图像揭示:白云凹陷中心的强负值异常图像与较厚沉积和基底起伏有关;凹陷东侧相对高正值局部重力圈闭与中生代残余地层有关;凹陷北侧条带状正异常则与陆坡向洋盆过渡时基底下凹有关。白云凹陷的主凹陷和南凹陷存在明显的层状负剩余密度或相对低密度区,是有利的含油气层位。地震图像揭示:白云凹陷由北向南存在明显的细颈化带、外缘隆起带、洋陆过渡带等结构。在陆缘地壳强烈伸展薄化期间,白云凹陷形成大型三角洲-湖相烃源岩沉积环境的凹陷结构,沉积物源主体来自北侧。随着地壳强烈减薄的细颈化,凹陷出现明显的台阶式沉陷,导致陆架坡折带由南向北迁移,形成陆架边缘三角洲、深水重力流水道和深水扇等有利的储层。高分辨率地震资料获取的地震勘探剖面图像上,可以识别出许多浅层气运移通道,表明白云凹陷丰富的中、浅层气大多来源于深部地层。      

根据烈度分布确定华北历史地震破裂区的经验准则及其应用

地震破裂区是地震时沿发震断裂带的同震错动面或破裂面在地表的垂直投影区域,指示了震源断层/破裂的位置与尺度。确定过去长期的强震/大地震破裂区是鉴别地震空区、研究与预测强震危险性的重要基础。对于现代强震,破裂区可运用多种现代技术方法确定,但对于历史强震,破裂区确定的方法需要探索与发展。以华北地区为例,研究利用烈度/等震线资料、结合地震构造与震区地表地质环境等信息确定历史强震破裂区的方法,并开展应用试验。结果表明:研究区现代地震破裂区延伸的烈度区间与极震区烈度、震区环境之间存在密切关系,基于这种关系建立了2条经验准则,可分别用于根据烈度分布确定华北2类震区环境(基岩区和厚层第四纪松散堆积覆盖区)历史强震破裂区的位置与延伸。文中还提出通过综合地震构造、现代小震/余震分布等信息,辅助确定历史强震破裂区横向宽度的思路与途径。作为应用试验,文中确定了5次历史地震的破裂区,结果表明本文发展的经验准则及相应方法适用于华北地区历史强震破裂区的确定。     

2008年10月5日新疆乌恰6．8级地震及其6．3级余震定位分析

利用台阵分析软件、“十五项目”地震分析软件,结合新疆强震台网数据与新疆地震台网数据的交切法和俄罗斯科学院提供的比什凯克科学站地震数据、新疆强震台网数据与新疆地震台网数据的交切法,对2008年10月5日乌恰6．8级地震进行了重新定位。分别采用4种方法进行定位,对定位结果进行比较与讨论。分析后判定,2008年10月5日乌恰6．8级地震类型为主震余震型。并利用新疆地震台网清晰震相对6．3级余震也进行了定位。     

On distortion of real values of magnitudes

Summary There are considered magnitude values distortions because of not taking into account the properties of links of the system where seismic waves are excited, spread and registrated. The links are: the source, the medium, the thickness of rocks, forming the upper part of seismo-geological section at the station region, seismic channel and processing methods of considered data. The system links are divided into nonoperating (source, medium) and operating (seismogeological section at the station region, seismic channel parameters, processing methods), which can be changed to a certain extent while registrating seismic oscillations.Strong distortion of narrow band shortperiod and longperiod instrumentation of seismic records is shown. This brings to considerable decreasing magnitude values comparing with the values determined by the records of broad band instrumentation. In order to decrease the magnitude distortion there is recommended the passing to registration. In order to decrease the magnitude distortion there is recommended the passing to registration of seismic oscillations by broad band receiving channels with large dynamic range of 100–120 decibel with magnetic tape digital registration and following processing of the data by the computers.There is pointed out that seismic stations installation at unweathered crystalline rocks is the most favourable, and a special attention is drawn to necessity of correct choice of the processing methods of the net stations data while calculating the averaged magnitude values.At present before the complete passing to broad band digital registration there is suggested to determine magnitudes in the international centers on the data by specially chosen stations supplied by most broad band instrumentation, using existing standard scales, practically coinciding with Gutenberg-Richter's scales.     

High-resolution seismic stratigraphy of the Yamato Basin, Japan Sea and its geological application

Abstract High-resolution seismic stratigraphy of the Yamato Basin, Japan Sea, was successfully established using core-log-seismic data integration. The construction of synthetic seismograms by the combination of physical properties and well-log data from the Ocean Drilling Program (ODP) Site 797 was the key to accomplishing the high-resolution seismic stratigraphy. To achieve resolution comparable with well-log data and core lithology, single channel seismic reflection data taken from ODP underway geophysics were reprocessed, and then carefully compared with synthetic seismogram, core and well log profiles to identify seismic units. Ten seismic stratigraphic units were identified at the site, and seismic stratigraphic interpretation was successfully extended from the site to the nearby area along the Yamato Basin margin. The opal-A/opal-CT (biogenic silica/metastable diagenetic silica) boundary has different appearances at places from strong to weak, and mostly discontinuous. One of the significant results achieved from this study is clear distinction of the opal-A/CT boundary from a very strong reflector, which appears at 22 m below the opal-A/CT boundary. Through well-log and physical properties characterization of the different units, resistivity was found to be the best indicator of diatom content and with gamma-ray it also is an indicator of chert layers in the opal-CT zone. Velocity is not greatly effected by diatom ooze in the opal-A zone, however, it shows strong peaks and has an indirect relationship with gamma-ray in the opal-CT zone. Finally, successful correlation of Gamma-ray Attenuation Porosity Evaluator density and resistivity peaks with strong seismic reflectors from upper and lower stratified layers may provide new information on the late Neogene paleoceanography of the Japan Sea in high-resolution scale.     

全方位自然电场观测方法和观测技术研究

自然电场是一种物理意义比较明确, 变化(孕震)机理相对明晰的地球物理场, 在矿产资源勘探、 水文地质勘测等领域有着比较广泛的应用, 在地震监测领域也有了多年的探索和实践. 本文在初步研究全方位自然电场观测方法的基础上, 重点分析和讨论了基于全方位自然电场观测技术, 包括一种Pb-PbCl₂不极化电极、 多测道高精度数据测量、 网络控制与数据通信等组件和模块的基本原理和技术实现方法, 便携式设计和环境温度适应能力的技术实现途径等, 并对天津市静海地震台的自然电场试验观测系统及观测数据进行了简要介绍和分析讨论. 结果表明: ① 全方位自然电场观测方法能够捕捉到各个方向自然电场及其随时间的变化; ② 自然电场观测技术系统能够配合全方位自然电场观测方法, 在360°范围内开展自然电场及其随时间变化的动态变化测量, 具有较高的观测精度、 较强的抗干扰能力和观测环境适应能力; ③ 天津市静海地震台的试验观测系统记录到了可能与周边水系的季节性变化有关的自然电场全方位变化.