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1.
地震资料连片叠前深度偏移处理目前仍旧存在着区块间能量不均、频率差异、空面元、覆盖次数差异大、速度难以求准等突出问题.针对以上现状,本文采用振幅匹配及匹配滤波等技术,确保区块间振幅能量分布,解决频率差异,保证子波特征分布均匀,无闭合差存在;研究并采用了两步法数据规则化方法,即基于反假频傅里叶重构的空间内插和基于Voronoi多边形的振幅归一化技术,改善由于空面元和覆盖次数不均造成的偏移划弧现象.在此基础上,研究了叠前深度层析反演速度建模技术,解决连片速度问题,给出叠前深度偏移的速度体.将上述连片处理关键技术应用于实际资料后,偏移剖面无空间假频存在,成像效果明显提高,并在油田勘探中取得了显著的实际应用效果. 相似文献
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针对玛湖斜坡区三块三维地震资料和赛汉塔拉凹陷二块三维地震资料连片处理中的特点，结合地质任务和处理目标要求，提出了地震数据连片处理中的地震子波处理的方法.该方法主要体现了两次反褶积，一次是采用地表一致性反褶积，将不同震源的频带拓宽到一个标准上；再一次采用相位校正反褶积，将不同震源的数据校正到相同相位上.为了保证提取的相位校正反褶积算子稳定，采用叠后地震道提取（主要考虑到叠后地震道信噪比高，算子稳定性强），然后将该算子应用到叠前地震道，进行相位校正. 相似文献
4.
《地球物理学进展》2017,(1)
受地震勘探资料的采集施工方法、地表激发接收条件、复杂的地下传播介质等因素的影响会导致同一区块同一地层反射波组的频率、波形不同,静校正不彻底、速度不准会导致剩余时差,动校正拉伸会导致波形畸变,通常在常规一致性处理后的CMP/CRP道集数据仍然存在一些不一致性问题,会影响资料潜力的发挥,资料的一致性处理对处理成果品质的提高起到至关重要的作用,尤其是在多块三维连片处理、时延地震处理、过渡带探区资料处理、叠前反演处理、高分辨率处理、高精度成像处理等方面均对资料的一致性提出了更高的要求.针对该现实问题,介绍了依赖于图像的相似和有局部光滑变形(或位移)场的非刚性匹配处理技术.该技术在常规一致性处理的基础上,首先将叠前数据分选成炮检距数据,优选部分炮检距数据形成模型,然后对每一炮检距数据逐一与模型进行非刚性匹配,实现数据的一致性处理.给出了实际资料非刚性匹配一致性处理的效果,证实了该技术在提高数据的一致性、改善数据处理成果品质、保持分辨率不降低和振幅保真方面具有一定的优势.因此,该技术可适用于时延地震匹配处理、叠前角道集拉平、叠前CMP/CRP道集拉平、振幅随角度变化(AVA)处理、PS波与PP波同相轴匹配处理等. 相似文献
5.
对以往三维地震勘探原始资料进行连片处理是目前煤矿采区地震勘探中正在兴起的新方向.连片处理中,由于地形起伏大,低速带速度和厚度纵横向变化剧烈,常规静校正存在着较大局限性.因此,如何拼接地震数据,达到理想的地质效果是关键.应用层析静校正对山西郑庄煤矿三个区块的三维地震勘探原始数据进行重新连片处理,区块之间实现无缝拼接,初至波光滑,煤层反射波连续性好.利用连片处理后的数据体对以往解释成果进行修改,收到令人满意的地质效果. 相似文献
6.
地震子波在叠前时间偏移前、偏移过程中以及偏移后具有不同特性和非稳态性,使得基于子波压缩原理的反褶积和基于绕射叠加原理的叠前时间偏移不能有效地提高薄互层地震分辨率.本文基于叠前时间偏移前后以及偏移过程中地震子波频率特性的分析,联合三种高分辨率处理方法对薄互层进行成像,即偏移前CMP道集应用反Q滤波补偿高频衰减、偏移过程中应用最优加权Kirchhoff叠前时间偏移降低高频损失、偏移后在CRP道集上应用子波调谐反褶积拓展频带.数值分析和实例证明,本文采用的三种高分辨率处理方法是必要的,对刻画薄互层厚度与边界能够取得好的效果,利于后续的岩性储层预测与AVO/AVP/AVA反演. 相似文献
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目前常用叠前深度偏移主要有四种:基于射线理论的Kirchhoff偏移和高斯束偏移以及基于波动方程理论的单程波偏移和逆时偏移.要想在实际应用中取得好的成像效果,必须选取合理、有效的叠前深度偏移算法.本文首先简单阐述了这四种常用叠前深度偏移方法的基本原理,对比分析了四种方法在陡倾角、速度依赖性、起伏地表、非规则数据、低信噪比数据等方面的优劣性以及计算效率和计算精度的差异,然后利用模型试算和实际资料处理分析说明这四种叠前深度偏移方法的成像效果,最后给出不同情况下叠前深度偏移方法的选取建议. 相似文献
8.
叠前地震资料中,高频分量和低频分量随传播距离的衰减特性不同.本文给出了一种在小波域定性估计叠前地震资料衰减参数的方法.该方法利用连续小波变换提取共反射点道集的高、低频分量,以低频分量和高频分量之差定性反映地震波的衰减.通过累加不同偏移距的衰减,提高了估计的稳定性;采用幅度归一化方法,降低了信号幅值对衰减参数估计的影响.将本文提出方法与常用的基于叠后地震资料衰减估计方法用于某油田的地震资料处理,结果表明,本文方法得到的衰减估计结果能够更好地反映油气的空间展布. 相似文献
9.
陆上地震勘探中多采用速度型检波器接收,随着单点高密度地震勘探的开展,加速度型检波器也被日趋广泛的应用.这两种检波器接收的地震信号具有不同的响应特征,在地震勘探中经常会遇到这样的情况:两个相邻区块分别应用速度型检波器和加速度型检波器接收,需要将这两个区块的地震资料进行连片处理,两类检波器接收资料如何处理拼接?本文在理论上分析了加速度检波器测量的加速度信号和速度检波器测量的速度信号之间的数学关系;并通过数值数据模拟分析、实际的地震数据资料分析证明了加速度信号通过积分计算以及去除积分误差后转化为速度信号的可行性和正确性,并进行了相应的对比和验证.在不同类型检波器接收地震资料的拼接处理过程中应用这种转换方法进行资料处理,得到一致性很好的地震剖面. 相似文献
10.
对地下地质构造进行正确成像是地震勘探的最终目的,由于三维地震资料采集不可能都沿垂直构造走向的方向进行,为地震资料的三维处理带来了许多困难. 本文将三维叠后拉东投影偏移思想应用于三维叠前处理中,提出了三维叠前投影偏移算法. 利用拉东投影变换的原理,将整个三维叠前数据体投影到一系列各方向的径向线上,各方位角的构造都包含在其中某条或多条径向剖面上. 投影完成后,形成一系列的独立的二维叠前测线,可采用二维叠前深度偏移成像方法来实现各径向线的叠前偏移,当各径向剖面偏移完成后,在时间切片上进行反投影,从而最终形成三维叠前深度偏移结果. 实际应用表明,用本方法进行三维叠前深度偏移时,深度偏移剖面对横向分辨率有所提高,对陡地层和小断层的成像效果有所改善. 相似文献
11.
松辽盆地地层吸收特性和地震波衰减规律研究 总被引：5，自引：1，他引：5
选取有代表性的岩石样本，实验室模拟地下岩层的实际物理状态，对P波的品质因素Q和波速进行了测试，结果表明，松辽盆地地下岩层的P波Q和波速皆随压力的增中呈线性增加，随温度的增加呈线性减小；且Q与波速符合幂律关系，粘弹介质地震波场正演模拟表明，导致地震波衰减的主要是第四系低速带的影响，通过对震测井资料估算，按目前的地震采集方式，即潜水面（低速带）以下激发，检波器地面接收，从激发到接收，地震波在第四系中高频成分将损失170Hz，在最理想情况下，爆炸震源激发的初始子波频宽为402Hz，经过第四系和下伏地层吸收，第四系以下的反射波频带宽度不会超过232Hz，这是松辽盆地受地层吸收限制的高频采集极限。 相似文献
12.
On three-dimensional geological modeling and visualization 总被引：9，自引：0，他引：9
WU Qiang & XU Hua . Department of Resource Exploitation Engineering China University of Mining Technology Beijing China . Beijing Institute of Petrochemical Technology Beijing China 《中国科学D辑(英文版)》2004,47(8):739-748
3D geological modeling and visualization are the key technique issues to implement the plan of 揇igital Earth? At present, the major difficulties in 3D geo-logical modeling are as follows[1—5]: (1) 3D spatial data are difficult to acquire. What 3D geological modeling of complex objects and visu-alization depend on is the original data. However, it is very difficult to establish 3D complex geological models when the sampled data are sparse and insuffi-cient, the seismic profile data are lack… 相似文献
13.
Due to the influence of volcanic rock or weathering crust coverage, the quality of deep seismic data is often not reliable and it is difficult to identify small deep buried hill structure beneath the cover. However, the gravity exploration technology can use the remarkable density differences between the object and the overlying strata to identify this special geological reservoir. Although recently several rounds of seismic exploration have been carried out in Raoyang depression, Huabei Oilfield, North China to determine the existence of Hu 8 north deep buried hill, whether the buried hill really exists or not as well as its scale is still in controversial. In this paper, based on the information of seismic data and formation density, deep processing of 3D high precision ground gravity data has been carried out for 3D forward and inversion computation. The dimensional gravity forward calculation results show that the density of the deep anomaly body forms a relatively low gravity anomaly in the earth's surface. By using the potential processing method of vertical second derivative, and sliding filtering, the residual anomaly is separated from regional or background field, which illustrates the existence of a local high gravity anomaly at Hu 8 north area. According to the amplitude of residual gravity anomaly and formation density difference modeling, through a number of 3D forward calculations and 3D inversion of gravity data, the existence of Hu 8 north buried hill and its possible scale are basically determined. The results prove that the 3D high precision gravity method is effective in determining the deep buried hill structure in case that seismic data is not reliable. 相似文献
14.
E. V. Verzhbitskii M. V. Kononov V. D. Kotelkin 《Journal of Volcanology and Seismology》2007,1(6):357-371
The distribution of heat flow in the North Pacific Ocean has been examined, and a map of geothermal and geomagnetic fields for the Bering Sea as it is known today has been made. Reliable data are lacking regarding the time of origin for features of oceanic and continental genesis in the Bering Sea, which is an obstacle to the study of geodynamic processes in the North Pacific. Heat flow data were used to yield numerical estimates for the age of seafloor features in the Bering Sea: the Kamchatka Basin (21 Ma), Shirshov Ridge (95 Ma for the northern part and 33 Ma for the southern), the Aleutian Basin (70 Ma), Vitus Rise (44 Ma), Bowers Ridge (30 Ma), and Bowers Basin (40 Ma). These age estimates are corroborated by combined geological, geophysical, and plate kinematic data. A thermochemical model of global mantle convection has been developed in order to perform a numerical simulation of the thermal process involved in the generation of extended regional features in the North Pacific (the Emperor Fracture Zone, Chinook Trough, etc.). The modeling suggests a plume-tectonic origin for these features, yielding the optimal model for the tectonic evolution of the North Pacific. An integrated geological and geothermal analysis leads to the conclusion that the northern and southern parts of the Shirshov Ridge are different, not only in geologic age, but also in tectonic structure. The northern part is of imbricated-thrust terrane origin, while the southern part is of ensimatic island-arc origin, similar to that of Bowers Ridge. The seafloor of the Aleutian Basin is an outlier of the Upper Cretaceous Kula plate where, in the Vitus Rise area, backarc spreading processes originated during Eocene time. The terminating phase of activity in the Bering Sea began about 21 Ma by spreading in the older seafloor of the Kamchatka Basin. We developed plate-tectonic reconstructions of evolution for the North Pacific for the times 21, 33, 40, and 70 Ma in the hotspot system based on age estimates for the seafloor features derived from heat flow data and modeling of the thermal generation of regional faults, as well as on an analysis of geomagnetic, tectonic, and geological data. 相似文献
15.
CSAMT在山区金属矿勘查中,采用各种滤波和相位积分之类的处理方法,校正因地形起伏和局部电性不均匀引起的静态效应,往往难保奏效,开发消除静态效应的新方法是提高CSAMT资料处理与解释水平和方法应用效果的重要研究课题. 本文以如何消除地形影响为重点,对起伏地形下CSAMT二维大地三维源地电模型,采用加权余弦数值积分法,进行波数域电磁场二维有限单元法正演. 为模拟复杂地形地电模型,选取交叉对称网格三角形剖分法,实现了在国内常用赤道电偶极装置的CSAMT二维正演计算;在二维正演的基础上,开发了基于奥克姆反演法的CSAMT二维反演技术,研制出一套起伏地形下CSAMT二维正反演处理与解释方法技术系统. 通过理论模型试算和实测数据处理证实,本系统能有效地削减起伏地形影响. 在找矿应用中,该系统反演的电阻率断面,极大地消除了起伏地形影响和静态效应,突显出清晰的控矿构造和矿体的异常,取得了重要成效. 相似文献
16.
基于局部一维模型与走时标定的区域 三维速度模型构建技术研究 总被引：1，自引：0，他引：1
构建区域介质三维速度模型并以之获得准确的区域震相走时, 是提高区域地震定位精度的重要手段之一. 为充分利用已有的一维模型、 GT事件、 地质资料等实现三维模型构建, 尝试基于目标区域内已有的部分局部一维模型, 通过克里金空间插值建立初始三维模型, 然后利用GT事件走时数据并参考其它地震地质资料对其不断进行修正, 使得其走时偏差图与GT事件走时偏差图一致, 进而获得能够提高区域地震定位精度的三维模型. 使用不同模型进行的地震定位实验表明, 以此方法建立的三维模型的定位偏差较初始模型减少约20%, 较好地起到了减小区域震相走时残差, 提高区域地震定位精度的作用. 相似文献
17.
A set of geophysical data collected in an area in Iran are analyzed to check the validity of a geological map that was prepared in connection to a mineral prospecting project and also to image the spatial electrical resistivity distribution. The data set includes helicopter electromagnetic (HEM), airborne magnetic and ground electrical resistivity measurement. Occam approach was used to invert the HEM data to model the resistivity using a layered earth model with fixed thicknesses. The algorithm is based on a nonlinear inverse problem in a least-squares sense.The algorithm was tested on a part of an HEM dataset acquired with a DIGHEM helicopter EM system at Kalat-e-Reshm, Semnan in Iran. The area contains a resistive porphyry andesite that is covered by Eocene sedimentary units. The results are shown as resistivity sections and maps confirming the existence of an arc like resistive structure in the survey area. The resistive andesite seems to be thicker than it is indicated in the geological maps. The results are compared with the reduced to the pole (RTP) airborne magnetic anomaly field data as well as with two ground resistivity profiles. We found reasonable correlations between the HEM 1D resistivity models and 2D models from electrical resistivity tomography (ERT) inversions. A 3D visualization of the 1D models along all flight lines provided a useful tool for the study of spatial variations of the resistivity structure in the investigation area. 相似文献
18.
区域地壳速度结构对于地震定位和地球动力学特征认识十分重要，一直是地震反演研究的主要内容。利用收集到的基于背景噪声面波成像方法的瑞利面波相速度数据，我们对苏北—南黄海地区地下三维S波速度结构开展了深度反演，进而探讨苏北—南黄海盆地地质结构与地震构造的关系。面波层析成像结果表明区域速度结构模型与地质特征基本一致，速度结构清晰刻画出了苏北—南黄海沉积盆地的主要沉积构造范围和基底起伏。反演结果还揭示了南黄海盆地中地壳内存在一显著的低速层，与历史强震集中分布区高度一致，表明浅源强震活动与壳内的低速层密切相关。 相似文献
19.
Joint inversion of long‐offset and central‐loop transient electromagnetic data: Application to a mud volcano exploration in Perekishkul,Azerbaijan 
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下载免费PDF全文 J. Adrian R. Bergers M. Gurk B. Tezkan A. L. Mammadov A. G. Novruzov 《Geophysical Prospecting》2015,63(2):478-494
Mud volcanism is commonly observed in Azerbaijan and the surrounding South Caspian Basin. This natural phenomenon is very similar to magmatic volcanoes but differs in one considerable aspect: Magmatic volcanoes are generally the result of ascending molten rock within the Earth's crust, whereas mud volcanoes are characterised by expelling mixtures of water, mud, and gas. The majority of mud volcanoes have been observed on ocean floors or in deep sedimentary basins, such as those found in Azerbaijan. Furthermore, their occurrences in Azerbaijan are generally closely associated with hydrocarbon reservoirs and are therefore of immense economic and geological interest. The broadside long‐offset transient electromagnetic method and the central‐loop transient electromagnetic method were applied to study the inner structure of such mud volcanoes and to determine the depth of a resistive geological formation that is predicted to contain the majority of the hydrocarbon reservoirs in the survey area. One‐dimensional joint inversion of central‐loop and long‐offset transient electromagnetic data was performed using the inversion schemes of Occam and Marquardt. By using the joint inversion models, a subsurface resistivity structure ranging from the surface to a depth of approximately 7 km was determined. Along a profile running perpendicular to the assumed strike direction, lateral resistivity variations could only be determined in the shallow depth range using the transient electromagnetic data. An attempt to resolve further two‐dimensional/three‐dimensional resistivity structures, representing possible mud migration paths at large depths using the long‐offset transient electromagnetic data, failed. Moreover, the joint inversion models led to ambiguous results regarding the depth and resistivity of the hydrocarbon target formation due to poor resolution at great depths (>5 km). Thus, 1D/2D modelling studies were subsequently performed to investigate the influence of the resistive terminating half‐space on the measured long‐offset transient electromagnetic data. The 1D joint inversion models were utilised as starting models for both the 1D and 2D modelling studies. The results tend to show that a resistive terminating half‐space, implying the presence of the target formation, is the favourable geological setting. Furthermore, the 2D modelling study aimed to fit all measured long‐offset transient electromagnetic Ex transients along the profile simultaneously. Consequently, 3125 2D forward calculations were necessary to determine the best‐fit resistivity model. The results are consistent with the 1D inversion, indicating that the data are best described by a resistive terminating half‐space, although the resistivity and depth cannot be determined clearly. 相似文献
20.
Magnetotelluric surveys were conducted to investigate the structure in the El Hito Anticline in the southern Loranca Basin, Spain. The structure of this anticline is partly known from nearby data (geological cross sections, geological maps, well-logs) from vintage geophysical and geological basin-scale surveys. Unfortunately, these surveys do not have the appropriate resolution to determine certain characteristics of the anticline accurately, such as the thickness or geometry of geological units. To address this deficiency, magnetotelluric data were acquired at 51 sites along three profiles to image the electrical resistivity of the anticline. To identify a geologically reasonable resistivity model, a conceptual model based on previous geological and geophysical information (cross sections and well-log data) was generated. Several inversions were performed using the conceptual model, which played a key role in the interpretation of the magnetotelluric data, and the construction of a suitable initial model was essential in producing geologically meaningful models. Using these results, we obtained 2-D resistivity models that provide information on the main geological units and structures. We also performed sensitivity tests to understand the morphology and structure of the resistive basement better. The results indicate the presence of basement highs that show different structural styles for the basement and its cover, and an increase in the basement depth towards the south. The final 2-D resistivity models provide new information regarding the structure of the anticline and demonstrate a clear correlation between the main geological units and resistivity, as well as correlations with mapped surface faults. 相似文献