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1.
东非裂谷Albertine地堑是当今世界油气勘探的热点地区之一,具有埋藏浅、演化快、地层新的地质特点。作为主力含油气层段的新生代地层中疏松砂岩异常发育,物性参数差异较大,受控于孔隙度以及孔隙流体的综合影响,含油气储层的地震响应无明显规律,油气预测难度较大。基于能量吸收分析思想的指导,在利用匹配追踪时频分解方法有效提高时频分辨率的前提下,进一步提出瞬时能量异常属性的计算方法。以Albertine地堑的W油田为例,针对含油气储层表现的低频能量增加、高频能量衰减的异常特征,借助瞬时能量异常属性实现了油气预测,预测结果获得了钻井的验证。 相似文献
2.
The seismic instantaneous frequency attribute has been applied to interpret a depositional layer. Instead of the standard instantaneous frequency, the Caputo fractional differential operator has been demonstrated as a more suitable mathematical tool of nonlinear analysis for the depositional layer. Based on the Caputo operator, we propose a fractional extension of instantaneous frequency attribute to detect thin layers of sandstone formations. From numerical analysis of a 25-Hz Ricker wavelet, we found that the fractional instantaneous frequency of 0.99 order keeps an approximation of standard instantaneous frequency and enhances the negative frequency (anomalous frequency spike), which help in more precise geological interpretation. A three-layer wedge model and a case history from the Bohai Bay Basin showed that the 0.99 order instantaneous frequency provides more depositional sandstone information than the standard instantaneous frequency. The anomalous frequency spike, at the merging point of the top and the base reflections or at the tip of the stratum, of 0.99 order instantaneous frequency is more prominent than that of the standard one. The results help to interpret the thickness changes of thin sandstone formations. In practical application, the 0.99 order instantaneous frequency has revealed several deposition phases and lateral heterogeneity of a fluvial reservoir system. Therefore, the 0.99 order instantaneous frequency is a valuable seismic attribute for reservoir characterization. 相似文献
3.
基于频率域峰值属性的河道砂体定量预测及应用(英文) 总被引：1，自引：1，他引：0
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。 相似文献
4.
北黄海盆地是中国东部勘探及研究程度较低的含油气盆地之一,从原始地震资料分析入手,利用研究区波阻抗、道积分、瞬时振幅、瞬时频率等多种地震资料特殊处理方法及AVO油气检测技术,并结合沉积相和区域地质资料,对北黄海中部坳陷A构造的储盖层分布、含油气性等油气地质条件进行分析预测,认为研究区A构造中新生带地层纵向上主要有两套有利的储盖组合,且构造中部和翼部含油气性较好。 相似文献
5.
地震属性分析技术一直是地震特殊处理和解释的主要研究内容.随着油气勘探开发的发展,地震属性分析技术已经成为油藏地球物理研究的核心内容,是勘探地震与开发地震之间纽带.本文针对鄂尔多斯盆地的低幅度构造、低孔隙、低渗透率、致密性隐蔽油气藏的特点,综合应用相干数据体分析、地震相自动分类定性识别砂体厚度、地震振幅属性分析、频谱分解、多井约束的储层叠后反演等叠后属性分析技术,探索了一套适合该区油气特征的储层横向预测及油气识别模式.为该区油气勘探开发,储量计算提供可靠依据.同时也为隐蔽性油气藏的勘探开发积累了经验. 相似文献
6.
介绍了地震属性分类及地质含义,并以彩16井区为例优选出对储层含油气性敏感的地震属性参数，建立它们与含油气性的关系，利用单属性及多属性聚类分析评价了目的层的储层质量，并进行了有利储层预测，并指出下一步的有利勘探目标. 相似文献
7.
频谱成像技术是近年来发展起来的一项基于频率谱分解的储层特色解释技术,是地震属性分析中重要组成部分.频谱成像技术具有在空间横向上分辨率高的特点,是一种利用三维地震资料的多尺度信息对储层进行高分辨率成像、检测储层时间厚度变化的工具.地震数据振幅谱可以识别地层的时间厚度变化,相位谱可以检测地质体横向不连续性,在确定油藏边界、计算地层厚度方面比传统地震属性研究方法具有更大的优势.频谱成像技术的核心模块是信号的时频分析,本文回顾了频谱成像技术的基本概念和目前在频谱成像中广泛应用的时频分析方法,简单介绍了几种新的时频分析方法:广义S变换和改进的匹配追踪算法. 相似文献
8.
To simulate the frequency-dependent response of turbidite reservoirs in the JZ Area, near the Bohai Sea, China, we apply a diffusive and viscous wave equation (DVWE), which takes into account diffusive and viscous attenuation and velocity dispersion in fluid-bearing poroelastic media. We use a seismic data-driven geological model building approach to produce physical parameter sections, which are then used to numerically synthesize the frequency-dependent seismic response in the DVWE-based simulation. The DVWE-based synthetic section shows the characteristic reflection and geometry of turbidites and delineates the phase delay, instantaneous dominant frequency decrease and magnitude attenuation related to the gas-bearing reservoir. The common frequency sections obtained by instantaneous spectral decomposition of the synthetic section show that a low-frequency shadow (LFS) lies immediately beneath the reservoir. Next, following the implications of the numerical simulation, we then apply LFS and fluid mobility to the data volume. Both hydrocarbon indicators clearly delineate the bright gas reservoir and its spatial distribution. The workflow and methodologies can be expected to be applicable to other frequency-dependent hydrocarbon indicators. 相似文献
9.
四维地震(4D seimic)主要是指利用重复三维地震测量资料进行油藏动态监测。在油田开发过程中,由于储层特性变化所引起的地震振幅异常、频率变化以及反射同相轴下拖现象等均可作为注蒸汽波及范围四维地震监测的良好识别标志。由于叠后地震资料中常常存在动校正速度不准、动校正拉伸畸变、剩余静校正误差、以及CDP道集中各道波形的差异性等多方面的问题,这会对叠后地震资料所反映出的四维地震异常特性产生影响,造成解释结果的差异性和不确定性。为此,本文尝试开展叠前地震属性反演研究,利用瞬时频率、瞬时频率梯度、能量衰减85%时的频率、最大振幅频率、最大振幅、总能量等多种衰减属性的叠前剖面及其差值剖面来定性解释四维地震实验区的注入蒸汽在剖面上的反映。 相似文献
10.
在地震解释与储层预测中,地震属性扮演着重要角色.在砂砾岩储层研究过程中,常规属性效果并不理想,无法满足实际应用的需要.而过零点个数,虽是一种不被人经常使用的地震属性,但我们发现在砂砾岩体油藏预测中应用效果良好.为此,研究过零点个数地震属性的定义与计算方法,讨论子波主频、砂岩厚度、泥岩夹层和地层韵律性等与它的关系,通过模型测试与实际资料应用对其做较全面的诠释.研究表明:(1)对于单一界面地震记录,过零点个数不随子波主频和波长的变化而变化;(2)砂岩厚度与过零点个数呈正相关,厚砂岩的过零点个数要比薄砂岩大;(3)砂体间存在的泥岩夹层,厚度变化对过零点个数影响较小,但它会影响波组的形态;(4)不规则沉积与均匀沉积相比,过零点个数属性值要大,因此,此属性比较适合多期次发育的砂砾岩体或其他薄互层结构的储层预测.总的来说,过零点个数地震属性能够有效地识别砂砾岩体发育区,可为此类储层预测提供了一种新的优势属性. 相似文献
11.
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。 相似文献
12.
The gold-bearing Upper Elsburg Reef clastic wedge (UER) in the South Deep gold mine in the Witwatersrand basin (South Africa) hosts the highly auriferous basal conglomerate known as the Elsburg Conglomerate (EC) reef. The reef is less than 20 m thick and together with quartzite and conglomerate beds in the UER (1–120 m thick) is below the seismic tuning thickness, or the dominant quarter wavelength. They are extremely difficult to identify on migrated seismic sections using traditional amplitude interpretations. In order to enhance the detection of the EC reef and its subcrop position against the overlying Ventersdorp Contact Reef (VCR), complex-trace seismic attributes, or instantaneous attributes and volume attribute analysis were applied on prestack time migrated (PSTM) seismic sections. In particular, the instantaneous phase and paraphase allowed the clear identification of the continuity of the EC reef, and overlapping and interfering wavelets produced by the convergence of VCR and the EC reef. In addition, these attributes increased confidence in the interpretation of the EC, in particular its offsets (faults), and its depth. A high correlation between the seismically determined depth of the EC reef and borehole intersections was observed, with several depth discrepancies below the vertical seismic resolution limit (~ 25 m). This information can now be incorporated into the current mine geological model, thus improving the resource evaluation of the Upper Elsburg Reef in the South Deep gold mine. 相似文献
13.
Wavelet‐based cepstrum decomposition of seismic data and its application in hydrocarbon detection 
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下载免费PDF全文 Ya‐juan Xue Jun‐xing Cao Ren‐fei Tian Hao‐kun Du Yao Yao 《Geophysical Prospecting》2016,64(6):1441-1453
How to use cepstrum analysis for reservoir characterization and hydrocarbon detection is an initial question of great interest to exploration seismologists. In this paper, wavelet‐based cepstrum decomposition is proposed as a valid technology for enhancing geophysical responses in specific frequency bands, in the same way as traditional spectrum decomposition methods do. The calculation of wavelet‐based cepstrum decomposition, which decomposes the original seismic volume into a series of common quefrency volumes, employs a sliding window to move over each seismic trace sample by sample. The key factor in wavelet‐based cepstrum decomposition is the selection of the sliding‐window length as it limits the frequency ranges of the common quefrency section. Comparison of the wavelet‐based cepstrum decomposition with traditional spectrum decomposition methods, such as short‐time Fourier transform and wavelet transform, is conducted to demonstrate the effectiveness of the wavelet‐based cepstrum decomposition and the relation between these two technologies. In hydrocarbon detection, seismic amplitude anomalies are detected using wavelet‐based cepstrum decomposition by utilizing the first and second common quefrency sections. This reduces the burden of needing dozens of seismic volumes to represent the response to different mono‐frequency sections in the interpretation of spectrum decomposition in conventional spectrum decomposition methods. The model test and the application of real data acquired from the Sulige gas field in the Ordos Basin, China, confirm the effectiveness of the seismic amplitude anomaly section using wavelet‐based cepstrum decomposition for discerning the strong amplitude anomalies at a particular quefrency buried in the broadband seismic response. Wavelet‐based cepstrum decomposition provides a new method for measuring the instantaneous cepstrum properties of a reservoir and offers a new field of processing and interpretation of seismic reflection data. 相似文献
14.
Musa S.D. Manzi Gordon R.J. Cooper Alireza Malehmir Raymond J. Durrheim 《Geophysical Prospecting》2020,68(1):145-163
Seismic detection of faults, dykes, potholes and iron-rich ultramafic pegmatitic bodies is of great importance to the platinum mining industry, as these structures affect safety and efficiency. The application of conventional seismic attributes (such as instantaneous amplitude, phase and frequency) in the hard-rock environment is more challenging than in soft-rock settings because the geology is often complex, reflections disrupted and the seismic energy strongly scattered. We have developed new seismic attributes that sharpen seismic reflections, enabling additional structural information to be extracted from hard-rock seismic data. The symmetry attribute is based on the invariance of an object with respect to transformations such as rotation and reflection; it is independent of the trace reflection amplitude, and hence a better indicator of the lateral continuity of thin and weak reflections. The reflection-continuity detector attribute is based on the Hilbert transform; it enhances the visibility of the peaks and troughs of the seismic traces, and hence the continuity of weak reflections. We demonstrate the effectiveness of these new seismic attributes by applying them to a legacy 3D seismic data set from the Bushveld Complex in South Africa. These seismic attributes show good detection of deep-seated thin (∼1.5 m thick) platinum ore bodies and their associated complex geological structures (faults, dykes, potholes and iron-rich ultramafic pegmatites). They provide a fast, cost-effective and efficient interpretation tool that, when coupled with horizon-based seismic attributes, can reveal structures not seen in conventional interpretations. 相似文献
15.
地震属性分析技术在地球物理勘探领域的广泛应用,启发研究人员将其应用于人工源宽角反射/折射深地震测深剖面的资料预处理和震相识别。采用札达-泉水沟深地震测深资料,提取振幅、信噪比、主频、瞬时带宽、瞬时高频能量等地震属性参数,分析不同参数的物理含义,挑选其中对界面变化敏感的参数,对深地震测深资料进行预处理,并利用P波和S波的联合扫描,提高震相识别的准确性。走时互换结果显示,采用地震属性参数可有效提高震相拾取的准确性,进而提高后续地壳速度结构反演结果的精度。 相似文献
16.
中深层天然气藏地震预测技术研究 总被引：1，自引：0，他引：1
济阳坳陷天然气资源丰富,已在多个层系发现了不同类型的中深层天然气藏,由于气藏地质条件、地震反射复杂,针对不同的气藏需采用不同的地震预测技术。本文在中深层天然气藏地质特点分析的基础上进行了岩石物理、地震反演、地震属性等预测技术研究,结果表明：中层气藏储层物性较好,储层与围岩的岩石物理参数差异明显,应用亮点、AVO、叠前弹性阻抗反演技术可较好地识别预测三角洲砂岩气藏;针对深层低孔低渗砂岩气藏,地震属性及多属性反演是有效的储层预测技术,并预测了孤北地区二叠系有利储集相带分布,结合构造分析,指出了孤北地区深层气勘探方向。 相似文献
17.
Luciana Orlando 《Geophysical Prospecting》2002,50(1):27-41
This paper reports the results of using the ground‐penetrating radar (GPR) method to detect light non‐aqueous phase liquids (LNAPL) floating on the water table in an area where the thickness of LNAPL present ranges from a few centimetres to several decimetres. To understand the GPR response in this context, GPR theoretical models are calculated using information from the literature and hydrogeological field data. The study revealed that in the case of LNAPL floating on the water table in a static condition, there is an increase in the reflection amplitude from the water table due to the decrease in the capillary fringe. Nevertheless the amplitude of reflection from the water table can discriminate the contaminated from the non‐contaminated zone. Apart from an analysis of the real traces, the analysis of some attributes of the complex trace, instantaneous amplitude, phase and frequency, are also good tools to detect hydrocarbons floating on the water table. Such attributes, depending on both the signal frequency and the hydrocarbon thickness, can also give information about the thickness of the hydrocarbon layer. It is concluded that analysing the lateral variations in signal amplitude of the real trace and in the amplitude, phase and instantaneous frequency of the complex signal permits the delimiting of the area polluted by the hydrocarbon. 相似文献
18.
Utilizing spectral decomposition to determine the distribution of injected CO2 at the Snøhvit Field 下载免费PDF全文
下载免费PDF全文 Time‐lapse 3D seismic reflection data, covering the CO2 storage operation at the Snøhvit gas field in the Barents Sea, show clear amplitude and time‐delay differences following injection. The nature and extent of these changes suggest that increased pore fluid pressure contributes to the observed seismic response, in addition to a saturation effect. Spectral decomposition using the smoothed pseudo‐Wigner–Ville distribution has been used to derive discrete‐frequency reflection amplitudes from around the base of the CO2 storage reservoir. These are utilized to determine the lateral variation in peak tuning frequency across the seismic anomaly as this provides a direct proxy for the thickness of the causative feature. Under the assumption that the lateral and vertical extents of the respective saturation and pressure changes following CO2 injection will be significantly different, discrete spectral amplitudes are used to distinguish between the two effects. A clear spatial separation is observed in the distribution of low‐ and high‐frequency tuning. This is used to discriminate between direct fluid substitution of CO2, as a thin layer, and pressure changes that are distributed across a greater thickness of the storage reservoir. The results reveal a striking correlation with findings derived from pressure and saturation discrimination algorithms based on amplitude versus offset analysis. 相似文献
19.
随着油气田开发程度越来越高,勘探难度越来越大,如东部的老油田已经进入开发的后期,如何识别薄层砂体是非常重要的工作之一,解决这些难题这势必需要更先进的技术.地震属性能够很好的反映砂体横向展布特征,但是单一属性无法定量预测砂体厚度,而多属性之间又存在多解性,因此有必要提炼地震属性之间的共同点,将地震属性进行信息融合,形成新的融合属性.针对这一问题,本文提出首先利用高频谐波提高地震数据的分辨率,在此基础上着重研究基于概率核的地震属性融合方法,融合了几种常见的地震属性,并结合波阻抗反演方法,预测了N873区块沙三6-3小层砂体厚度.结果显示该方法能够很好的反映砂体横向展布特征,避免了地震属性多解性问题,为提高砂体预测的精度,提供了新的思路和方法. 相似文献
20.
We evaluate the applicability and the effectiveness of the GPR attribute analysis for archaeological purposes and we test the attribute analysis on GPR data obtained in the river harbor area of the Aquileia Archaeological Park, NE Italy, where cultural heritage of the Roman imperial period is buried at different depths beneath a silty loam layer at an average depth not greater than 3–4 m. A multi-attribute approach is used to characterize the subsurface through several attribute categories, including instantaneous, section and volume attributes applied to quantities related not only to the reflection amplitude, but also to frequency and phase or other more complex parameters. The results allow the identification of different buried archaeological remains, from brick walls to isolated stone chunks also in a very complex environment characterized by several interconnected or superimposed archaeological remains. 相似文献