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测井曲线对垂向地层剖面具有较高的分辨率,但其横向探测范围有限。地震资料在水平方向上具有较密的采样间隔,但其垂向分辨率有限。地震响应对横向岩性(地层厚度或性质)的变化是灵敏的,虽然其垂向分辨率不能满足确定岩性变化的要求。按统计学,地震资料可用来检测井旁地震道的横向变化量。因而,利用地震资料作为传递函数,可以外推高分辨率的测井曲线。垂直地震剖面资料常用以校准地震资料和声波测井曲线,也用于井下外推地震/测井资料,以便划定目的层, 测井曲线与相应地震道进行对比校准,并作出统计评价。同样,将目的层处的地震道与参考道对比校准,用时间变量相关函数检查每个地震道与参考道的相似性。通过下式使测井资料与地震资料相结合。 G_t=C_t·R_t+(1-C_t)·S_t式中,c_t是相关系数;R_t是测井曲线;S_t是地震道。合成信号是外推的结果。它是利用地震道的相似性作为外推测井曲线适用性的一个准则。地震资料可用在地震道与地震测线上任何一条测井曲线都不相似的情况下。外推方法可以帮助解释人员用几种方法来解决疑难的地层学问题。按测井曲线确定的井位条件在横向上可能有局限性。可沿水平测线检查其他的井位条件。可确定剖面上的振幅包络线,以改善反射波的振幅比,及提高高分辨率测井资料的横向控制范围。
Logging curves have high resolution for vertical stratigraphic profiles, but their horizontal detection range is limited. Seismic data in the horizontal direction with a tight sampling interval, but its vertical resolution is limited. Seismic response is sensitive to changes in lateral lithology (thickness or nature of the formation), although its vertical resolution does not meet the requirement of determining lithologic changes. According to statistics, seismic data can be used to detect the horizontal variation of the seismic trace beside the well. Thus, using seismic data as a transfer function, high-resolution logs can be extrapolated. Vertical seismic profile data are commonly used to calibrate seismic data and acoustic logging curves. They are also used to extrapolate seismic / well data downhole so that target layers can be demarcated and well logs can be compared to corresponding seismic traces for statistical evaluation. Similarly, compare the seismic trace at the target level with the reference trace and check the similarity of each trace with the reference trace using the time-dependent correlation function. Log data is combined with seismic data using the following formula. G_t = C_t · R_t + (1-C_t) · S_t where c_t is the correlation coefficient; R_t is the well log; and S_t is the seismic trace. The composite signal is the result of extrapolation. It is a criterion that makes use of the similarity of seismic traces as a reference for the applicability of extrapolated well logs. Seismic data can be used in seismic traces and seismic traces of any one of the logging curve is not the case. Extrapolation methods can help explain how people use difficult ways to solve difficult formation problems. Well conditions, as determined by well logs, may have lateral limitations. Other well conditions can be checked along the horizontal line. The envelope of the amplitude of the profile can be determined to improve the amplitude ratio of the reflected wave and improve the lateral control range of the high resolution logging data.