物探技术论文翻译对照范例 - 澜月能源翻译

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Seismic Resolution and Thin-Bed Reflectivity Inversion 地震分辨率及薄层反射率反演

Ever since the seismic method wasintroduced,way back in the 1930s, enhancing the frequency bandwidth of surface seismic data has always been a quest for geophysicists. In fact, seismic resolution is the key toextraction of stratigraphic detail from seismic data and this has become more important over the last decade or so. Seismic resolutioncomprises two aspects – the verticaland horizontal resolution. The vertical resolution refers to the ability todistinguish two close seismicevents corresponding to different depth levels, and thehori- zontal or spatial resolutionis concerned with the ability  to distinguish and recognizetwo laterally displaced features as two distinct adjacent events. While both aspects are impor- tant for interpreting small featureson seismic data, here, we focus our attentionto the vertical resolution, recognizing that migration procedures are usuallyput in place for collapsing the Fresnel zones that enhance spatial resolution.
译文：自从上世纪30年代地震方法引入石油勘探后，石油地球物理学家一直在要求拓宽地震资料的频带宽度以便获得较高的分辨率。事实上，地震分辨率是从地震资料中获取更多地层信息的关键，而且在过去的十年左右变得越来越重要。地震分辨率包括两部分：纵向分辨率和横向分辨率。纵向分辨率指的是分辨两个相近反射界面对应地层厚度的能力，而横向或者空间分辨率则是区分和识别两个相邻反射轴对应地质体边界的能力。在利用地震资料解释局部细微特征时两种分辨率都显得很重要。考虑到在地震资料处理过程中可以采用偏移手段来减小菲涅尔带半径从而提高横向分辨能力，所以这里我们重点探讨一下纵向分辨率。

纵向分辨率 Vertical resolution
If the average spectrum of a seismic waveletis centered around 30Hz, which is usually the case, reservoirs having a thickness less than25 m, may not have top and base reflectorsresolved. This may sufficefor structural objectives, but strati-graphic targets are usually set to look for reservoirs 10 m or less in thickness. Attempts to achieve such objectives often lead to frequency enhancement procedures to be followed on surface seismic data. Conventional wisdom usually follows the conclusions enunciated by Widess (1973) some threedecades ago. Widess proposed λ/8 as the resolutionlimit,  λ being the predominant wavelength in the data. In the pres- ence of noise and the consequent broadening of the wavelet during its subsurface journey, this resolutionis usually taken to be only λ/4,  and geophysicists have been assuming this resolution limit as a gospel truth till now. So, wavelengthis the  yardstick  for  resolution,  which  in  turn  depends on velocity and frequency. Since there is nothing we can do for velocity, which shows a general increasing trend with depth, the key factor that determines resolutionaccording to the Widess model is frequency. Thus, for getting greater reflec-tion detail from seismic data, utmost care is exercised,first at the seismicdata acquisition stage in terms of field parame- ters, seismic sources and improved  recordingadopted, and secondly, during processing where attemptsare made to enhance the spectralbandwidth.

译文： 通常情况下，如果地震子波主频在30HZ左右，25米厚的储层在地震剖面上是不会有对应的顶底反射界面的。采用这种地震资料对于构造类目标识别可能不会有太大影响，但地质目标大部分都在10米以下或者更薄。为了分析这类目标体，由此提出了很多提高地震资料频率的方法。传统的经验大多来源于30年前Widess（1973）年提出来的观点。Widness认为λ/8为分辨率的极限，其中λ为波长。如果存在噪音或者是随着子波在地下传播范围增大，这个结论变为λ/4，直到现在地球物理学家还引为真理。由此可见，波长是分辨率的决定性因素，而波长又与速度和频率有关。对于速度我们是无法改变，它还是随深度增加而增大，那在Widess模型中关键因素就是频率了。因此，为了从地震数据中获取更丰富的反射信息，我们做了很多工作，首先从地震数据采集阶段开始，如对现场参数、地震震源和信号记录质量等进行优化，然后在处理阶段尝试拓宽频谱宽度。


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chutianshu

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Petrohunting

汉语表达的准确性需要提高。

Be_Better_Every

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海峰笑

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