论文部分内容阅读
薄层解释的关键在于提高地震记录的纵、横向分辨率。该文提出的薄层解释新方法有可能突破通常意义下地震记录的分辨率极限(λ/4或λ/8),数值计算表明可达到λ/32至λ/100。该方法利用小波变换将常规地震剖面分解为一系列中心频率不同的窄带地震记录,称为分频剖面。当通带宽度足够小时,窄带剖面将趋近于单色地震波剖面,利用薄层等地质异常体对地震波的干涉、调谐效应,在横向上可以有效地区别于涉及非干涉体,对薄层进行解释。但窄带剖面地震信号延续度大,要造成相邻地震同相轴的交叠,为此,文章提出了“沿层分频处理”及“高分辨率剖面重建”两种方法来解决这一问题。前者针对单一地层逐层处理,特别适合在地震工作站上操作。后者是将若干窄带剖面进行选择性的处理之后再进行剖面的高分辨重建。由于在重建过程中能方便地加入信噪分离和频带拓宽等重要处理步骤,因此可得到分辨率、信噪比都很好的地震剖面。使用该方法还可识别对应于同一隐蔽圈闭层位的纵、横波。文章还系统介绍了多波层位对比的其他方法,并在微机上初步建立了多波层位对比及综合解释系统。
The key to the thin layer interpretation is to improve the vertical and horizontal resolution of seismic records. The new method of thin-layer interpretation proposed in this paper is likely to break through the resolution limit (λ / 4 or λ / 8) of seismic records in the usual sense. Numerical calculations show that λ / 32 to λ / 100 can be achieved. The method uses wavelet transform to decompose the conventional seismic profile into a series of narrow-band seismic records with different center frequencies, which are called frequency-division profiles. When the passband width is small enough, the narrowband profile will approach the monochromatic seismic wave profile. By using the interference and tuning effect of the seismic layers such as thin layers on the seismic waves, the narrowband profile can be effectively distinguished from the non-interference body involved in the horizontal direction, Explanation. However, the continuation of the seismic signal in the narrowband section is large, which will cause the overlap of the adjacent seismic events. Therefore, two methods are proposed to solve the problem, such as “frequency division along the layers” and “high resolution reconstruction”. The former for a single formation layer by layer processing, especially suitable for operation on the seismic workstation. The latter is the selective processing of a number of narrow-band cross-section after the high-resolution reconstruction. Because of the important processing steps such as signal-to-noise separation and band broadening in the reconstruction process, seismic sections with good resolution and good signal-to-noise ratio can be obtained. Using this method, it is also possible to identify longitudinal and shear waves corresponding to the same hidden trap horizon. The article also systematically introduces other methods of multi-wave layer contrast, and initially establishes a multi-wave layer contrast and comprehensive interpretation system on the computer.