An overview of depth imaging in exploration geophysics
An overview of depth imaging in exploration geophysics
复制标题
DOI：
10.1190/1.3223188
复制
发表时间：
2009-12
期刊：
影响因子：
3.3
通讯作者：
J. Etgen;S. Gray;Yu Zhang
中科院分区：
文献类型：
--
作者：
J. Etgen;S. Gray;Yu Zhang
叠前深度偏移是地震处理中最迷人的步骤，因为它将单纯的数据转化为图像，并且该图像被认为是对地球的一种精确的构造描述。因此，我们对其准确性、稳健性和可靠性期望很高。令人惊讶的是，地震偏移通常都能达到预期。在过去的几十年里，偏移从其启发式的根源发展到了数学上合理的技术，这些技术利用相对较少的假设，绘制出地球内部的精确图像。有趣的是，地球以及我们想要成像的其内部的对象差异很大，以至于到目前为止，没有一种单一的偏移技术在实际应用中占据主导地位。所有技术都在不断改进并相互借鉴，所以一种技术可能永远不会占主导。尽管在构造成像方面取得了进展，但我们还没有达到地震图像能对岩石和流体进行定量精确描述的程度。我们也没有实现将偏移作为纯计算过程的一部分来确定地下速度的目标。在图像质量最高的区域，我们可能正在接近这些统称为反演的目标。在数据更具挑战性的区域，这些目标似乎难以实现。我们描述了深度偏移到目前为止所取得的进展以及未来实现其反演目标的最重大障碍。我们还推测了未来几年可能取得的进展以及偏移可能无法应对的挑战。
Prestack depth migration is the most glamorous step of seismic processing because it transforms mere data into an image, and that image is considered to be an accurate structuraldescriptionoftheearth.Thus,ourexpectationsofitsaccuracy, robustness, and reliability are high.Amazingly, seismic migration usually delivers. The past few decades have seen migration move from its heuristic roots to mathematically sound techniques that, using relatively few assumptions, render accurate pictures of the interior of the earth. Interestingly,theearthandthesubjectswewanttoimageinside itarevariedenoughthat,sofar,nosinglemigrationtechnique has dominated practical application.All techniques continually improve and borrow from each other, so one technique mayneverdominate.Despitetheprogressinstructuralimaging,wehavenotreachedthepointwhereseismicimagesprovide quantitatively accurate descriptions of rocks and fluids. Nor have we attained the goal of using migration as part of a purelycomputationalprocesstodeterminesubsurfacevelocity. In areas where images have the highest quality, we might be nearing those goals, collectively called inversion. Where data are more challenging, the goals seem elusive. We describe the progress made in depth migration to the present and the most significant barriers to attaining its inversion goalsinthefuture.Wealsoconjectureonprogresslikelytobe made in the years ahead and on challenges that migration mightnotbeabletomeet.