共查询到17条相似文献，搜索用时 140 毫秒
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OBC近年来得到长足的发展,但采集新技术的出现,相应地要求处理技术的开发和研究必须跟进,跟上世界先进技术的进步,才能更好地为油气的勘探工作做出应有的贡献.目前在OBC采集、处理方面还存在如下问题:如何客观评价现有OBC观测系统的优劣,如何评价采集资料的质量,如何评价现有OBC资料处理模块的效果等.为此,本文收集了靶区地震地质资料,建立了从陆坡区到深水区的二维和三维地震地质模型,基于二维和三维波动方程正演模拟技术,模拟给定的OBC观测系统下的P波和P-SV波炮集记录,根据多波资料处理结果评价对应的OBC观测系统的采集资料的效果.结果显示,OBC接收的地震波场特征复杂,地震波类型很多,合成记录的纵横波分离得到的纵波剖面和转换波剖面特征明显.靶区给定的OBC观测系统正演模拟结果表明,给定的观测系统下,复杂断层能得到较好的偏移成像,但复杂基底尤其是凹陷部位,成像效果较差. 相似文献
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以多分量地震观测为基础,联合纵波和转换横波数据能更有效地估计地下介质的弹性和物性参数,提升地质构造成像与油气储层描述的精度.在海底多分量地震数据处理过程中,观测记录的上-下行波分解和P/S波分离可压制水层鸣震以及P与S波之间的串扰,对偏移成像和纵横波速度建模至关重要.但受海底环境、仪器与观测因素共同影响,许多海底多分量地震资料都无法基于现有的海底波场分离方法与流程取得合理的结果.本文以海底声波场与弹性波场分离基本原理为基础,通过对方法流程的修正,摆脱常规流程对中小偏移距直达波信号的依赖性.借助模拟数据实验讨论了波场分离对海底介质参数、噪声的敏感性.结合东海YQ探区海底多分量地震资料上-下行P/S波分离及其叠前深度偏移处理,验证了本文方法流程的可行性. 相似文献
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《地球物理学进展》2015,(1)
本文以2013年度美国SEG年会上刊出的地震各向异性理论与多分量地震技术方面的学术论文为依据,通过各论文的技术剖析和对比分析,总结了该届年会所展示的多分量地震技术的发展趋势与研究热点.综合分析发现,多分量地震技术的发展具有如下几个明显的特点:1)油服企业成为多分量地震技术的主要推动者;2)成功应用的实例不断增长;3)海洋多波依然是多分量地震技术应用的主要领域,其中OBC、OBS、OBN与拖缆纵波的综合运用是其独有的特色;4)多分量地震数据处理与多波联合反演的一体化成为越来越明确的发展方向;5)纵横波速度及各向异性参数建模是制约多分量地震偏移成像的关键因素,也是当前的研发热点;6)在纵波成像与反演困难的成熟勘探与开发区域,是多波地震发挥效用的理想场所,而不仅限于致密气等非常规裂缝型油气储层. 相似文献
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本文对基于弹性波动理论的多波多分量高斯束偏移进行了完整且详细的分析和公式推导,实现了3D空间多分量(矢量)波场的直接成像.由于当前多数基于弹性波动方程的偏移方法只是假设应力边界条件为自由地表边界条件,这种假设不符合垂直地震剖面(VSP)和海底电缆(OBC)等地震数据.为此本文详细分析了实际应用中常见的三种弹性各向同性介质模型的应力边界条件:自由空间、海底和自由地表模型.在上行传播假设情况下,获得了应力边界条件与位移边界条件的关系式.在此基础上,准确推导了3D多波多分量高斯束波场延拓和偏移成像公式,并在偏移过程中实现了完整的多波型自动分离.由于常规的互相关成像条件不适用于矢量波场成像,本文引用了散度/旋度互相关成像条件.通过约定PS转换波的正向旋转方向解决了3D空间PS成像极性翻转问题.利用2D和3D模型数据偏移成像验证了我们所提出的多波多分量高斯束偏移方法的可行性. 相似文献
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2014CPS/SEG国际地球物理会议在北京成功召开,会议发表了关于地震资料采集、处理、解释和其它应用的300余篇学术论文.本次会议整体上注重技术创新和创新技术的应用,会议成果表明,GPU并行计算基本渗透到地震资料处理的各个环节,对于偏移成像来说,该技术使得逆时偏移和全波形反演的工业化大规模应用成为可能;对地震成像技术而言,各向异性TTI介质的声波方程和弹性波方程的逆时偏移仍是地震技术发展的重要方向,提供高精度速度模型和弹性参数的三维波动方程的全波形反演技术是未来十年,乃至更长时间的攻关研究方向.随着勘探的复杂化,非常规油气的地球物理技术和微地震压裂的检测方法正逐渐成为地球物理工作者重视的研究内容;另外,开发和井中地球物理技术是油藏开发后期的剩余油预测、油藏描述和监测的关键技术. 相似文献
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VSP 转换波跟VSP 纵波或常规地面转换波相比，具有较高的分辨率和信噪比，但传统的VSP成像方法只利用了反射P波信息，而把转换波（反射S波、透射S波）以及透射P波当作影响成像质量的噪音.本文给出了一种VSP共炮点道集多分量地震资料克希霍夫法偏移成像的方法.本方法充分利用了多波（反射P波、反射S波、透射P波、透射S波）信息，根据转换点处四种波同时起跳，能量叠加最大的原理，从接收点分别用向绕射点延拓它们的能量，并将其叠加起来，求得的和最大的一点即反射点.通过模型试算和实际资料处理表明，此法成像精度高，信噪比高，且有利于改善剖面的频率特性. 相似文献
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纵波震源激发、三分量检波器接收的三分量地震勘探技术是解决复杂油气藏勘探的有效手段.在三分量地震勘探资料处理中,转换波资料处理尤为关键,转换波资料处理的难点之一是转换波静校正.研究了非转换型折射波和转换型折射波传播规律,发现形成PPS转换型折射波的有利条件是上覆介质横波速度比下伏介质横波速度要小很多,提出了基于PPS转换型折射波的转换波静校正方法,并对实际三分量地震资料进行了处理,转换波静校正取得了较好的效果. 相似文献
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我国南方碳酸盐岩广泛分布,具有巨大的油气资源潜力和勘探前景.全国油气资源战略选区调查与评价项目选择我国典型南方海相碳酸盐岩裸露区开展地震勘探技术攻关.针对该区地表灰岩普遍出露、激发弹性波能量转换少、散射噪音干扰严重等勘探难点,研究和应用了“宽线+折线”地震采集技术和与其配套的拟三维地震处理技术,能较好地压制噪音,提高剖面信噪比,在主要目的层得到了较好的成像效果,桂中1井钻探结果与地震勘探解释成果吻合较好,检验了该方法用于南方碳酸盐岩地区勘探的有效性. 相似文献
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海底电缆（OBC）采集方式的出现,导致OBC采集与拖缆采集数据进行拼接成为三维连片地震资料处理中的一个重要环节.由于采集方式不同,数据在振幅、频率、相位等方面均存在较大差异.为了消除和减小这些差异,为后续的地质解释和油气预测提供便利,本文提出了一种在子波域的1范数匹配滤波方法来计算匹配滤波因子,以用来提高OBC数据和拖缆数据的匹配精度,改善连片处理的数据品质,为后续的地质解释和油气预测提供便利.通过实际资料检验,子波域匹配滤波方法在OBC与拖缆数据拼接应用中取得了较好的效果. 相似文献
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川西坳陷孝泉地区深层须家河组致密砂岩气藏属于典型非常规裂缝性气藏,储层识别、裂缝检测、含气性识别是气藏研究的重点和难点.转换波3D3C勘探可同时获得反映岩石骨架和各向异性特性的C波资料及反映骨架及流体特性的P波资料,因而适用于川西孝泉深层超致密裂缝性气藏.在3D3C地震勘探中,三维三分量地震采集方法是采集到高质量多分量原始资料的技术保障,本文重点研究这种采集方法.首先根据地球物理参数,结合地质任务要求,分析了三维三分量观测系统设计的方法及观测系统参数,然后根据分析结果和勘探目的层的实际情况设计了同时适合纵波勘探和转换波勘探的面元尺寸、最大和最小炮检距、接收线距、束间滚动距等参数并确定了三维三分量观测系统.该观测系统在孝泉地区资料采集中,获得的三分量资料波组特征清楚,同相轴连续,反射信息丰富;Z分量剖面和R分量剖面反射层次清楚,目的层反射特征明显,具有非常好的构造形态一致性. 相似文献
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Due to the complicated geophysical character of tight gas sands in the Sulige gasfield of China, conventional surface seismic has faced great challenges in reservoir delineation. In order to improve this situation, a large‐scale 3D‐3C vertical seismic profiling (VSP) survey (more than 15 000 shots) was conducted simultaneously with 3D‐3C surface seismic data acquisition in this area in 2005. This paper presents a case study on the delineation of tight gas sands by use of multi‐component 3D VSP technology. Two imaging volumes (PP compressional wave; PSv converted wave) were generated with 3D‐3C VSP data processing. By comparison, the dominant frequencies of the 3D VSP images were 10–15 Hz higher than that of surface seismic images. Delineation of the tight gas sands is achieved by using the multi‐component information in the VSP data leading to reduce uncertainties in data interpretation. We performed a routine data interpretation on these images and developed a new attribute titled ‘Centroid Frequency Ratio of PSv and PP Waves’ for indication of the tight gas sands. The results demonstrated that the new attribute was sensitive to this type of reservoir. By combining geologic, drilling and log data, a comprehensive evaluation based on the 3D VSP data was conducted and a new well location for drilling was proposed. The major results in this paper tell us that successful application of 3D‐3C VSP technologies are only accomplished through a synthesis of many disciplines. We need detailed analysis to evaluate each step in planning, acquisition, processing and interpretation to achieve our objectives. High resolution, successful processing of multi‐component information, combination of PP and PSv volumes to extract useful attributes, receiver depth information and offset/ azimuth‐dependent anisotropy in the 3D VSP data are the major accomplishments derived from our attention to detail in the above steps. 相似文献
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Elastic imaging from ocean bottom cable (OBC) data can be challenging because it requires the prior estimation of both compressional‐wave (P‐wave) and shear‐wave (S‐wave) velocity fields. Seismic interferometry is an attractive technique for processing OBC data because it performs model‐independent redatuming; retrieving ‘pseudo‐sources’ at positions of the receivers. The purpose of this study is to investigate multicomponent applications of interferometry for processing OBC data. This translates into using interferometry to retrieve pseudo‐source data on the sea‐bed not only for multiple suppression but for obtaining P‐, converted P to S‐wave (PS‐wave) and possibly pure mode S‐waves. We discuss scattering‐based, elastic interferometry with synthetic and field OBC datasets. Conventional and scattering‐based interferometry integrands computed from a synthetic are compared to show that the latter yields little anti‐causal response. A four‐component (4C) pseudo‐source response retrieves pure‐mode S‐reflections as well at P‐ and PS‐reflections. Pseudo‐source responses observed in OBC data are related to P‐wave conversions at the seabed rather than to true horizontal or vertical point forces. From a Gulf of Mexico OBC data set, diagonal components from a nine‐component pseudo‐source response demonstrate that the P‐wave to S‐wave velocity ratio (VP/VS) at the sea‐bed is an important factor in the conversion of P to S for obtaining the pure‐mode S‐wave reflections. 相似文献
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P‐wave data from a time‐lapse 3D OBC survey have been analysed to estimate and interpret azimuthal seismic anisotropy. This is achieved by careful processing to preserve the azimuthal signature. The survey images a major reservoir body in a channelized turbidite field in the Gulf of Mexico. Three distinct and significant anisotropy anomalies are discovered on or around this particular ‘4500‐ft sand’, all of which change intensity but not orientation with hydrocarbon production. These anomalies are distributed along the highest concentration of cumulative sand thickness, with their symmetry axes aligned with the main channel axis. We suspect that this time‐lapse anisotropy could be caused by the alignment of the depositional grain fabric. Theoretical calculation predicts that this mechanism, when combined with fluid‐saturation changes, can generate the observed pattern of behaviour. If further supported by other researchers, this result would indicate that appropriately designed seismic surveys could be a useful tool for palaeo‐direction studies in clastic reservoirs and also a useful constraint for directional permeability in the reservoir flow simulation model. 相似文献
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AVO技术是Zoeppritz方程在地球物理勘探中的重要应用.本文在回顾Zoeppritz方程及其简化形式的基础上对AVO技术的最近发展进行了介绍.AVO技术是利用地震资料研究岩性和含油气性不可或缺的工具.近年来AVO理论和技术发展呈现新的方向,主要表现在以下几个方面:利用多波多分量地震数据进行纵波、横波、转换波的AVO分析,预测储层的含气性和检测裂缝发育;利用AVO技术定量表征岩性和储层的流体性质;进行3DAVO分析研究等.本文对此进行了介绍,并对AVO技术的前景进行了展望. 相似文献
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Antoine Roueff Jocelyn Chanussot Jerome I. Mars Minh-Quy Nguyen 《Geophysical Prospecting》2004,52(4):287-300
This paper illustrates the use of image processing techniques for separating seismic waves. Because of the non‐stationarity of seismic signals, the continuous wavelet transform is more suitable than the conventional Fourier transforms for the representation, and thus the analysis, of seismic processes. It provides a 2D representation, called a scalogram, of a 1D signal where the seismic events are well localized and isolated. Supervised methods based on this time‐scale representation have already been used to separate seismic events, but they require strong interactions with the geophysicist. This paper focuses on the use of the watershed algorithm to segment time‐scale representations of seismic signals, which leads to an automatic estimation of the wavelet representation of each wave separately. The computation of the inverse wavelet transform then leads to the reconstruction of the different waves. This segmentation, tracked over the different traces of the seismic profile, enables an accurate separation of the different wavefields. This method has been successfully validated on several real data sets. 相似文献