首页> 外文期刊>Geophysics >NONLINEAR WAVEFORM TOMOGRAPHY APPLIED TO CROSSHOLE SEISMIC DATA
【24h】

NONLINEAR WAVEFORM TOMOGRAPHY APPLIED TO CROSSHOLE SEISMIC DATA

机译:非线性波形层析成像技术在井眼地震数据中的应用

获取原文
获取原文并翻译 | 示例
       

摘要

The acoustic inverse problem of crosshold seismology is nonlinear in the medium velocities and ill-posed because of the lack of complete data coverage surrounding the area of interest. In light of these facts, this paper develops a new nonlinear waveform tomography technique for imaging acoustic velocities from crosshole seismic data. The technique, based on Tikhonov regularization, defines solution models that minimize the normed misfit between observed and modeled data subject to a constraint on the spatial roughness of the model. This type of regularization produces minimum structure velocity models which can vary in their degree of smoothness versus fit to the data. We solve the Tikhonov minimization condition numerically using a conjugate gradient algorithm. To accurately calculate the components of the forward problem, we use a frequency-domain integral equation method with sinc basis functions. The integral equation method discretizes the integral form of the acoustic wave equation over a 2-D area and produces a two-part matrix problem that we solve for Green's functions and total fields in the medium using general matrix decomposition techniques. We successfully apply nonlinear waveform tomography to a scale-model data set obtained from an ultrasonic modeling tank. This data set comes from a mostly plane-layered, epoxy-resin model, and the data exhibit elastic effects and other complicated wave phenomena. We invert this data set for the lateral variations in the model using a smoothed 1-D starting model to demonstrate the usefulness and efficacy of nonlinear waveform tomography. [References: 40]
机译:交叉点地震的声学反问题在介质速度中是非线性的,并且由于缺乏围绕感兴趣区域的完整数据覆盖而不适当地定位。鉴于这些事实,本文开发了一种新的非线性波形层析成像技术,用于根据井眼地震数据对声速成像。该技术基于Tikhonov正则化,定义了解决方案模型,该模型可最大程度地减少观测数据和建模数据之间的范数不匹配,但该模型会受到模型空间粗糙度的约束。这种类型的规则化会产生最小的结构速度模型,该模型的平滑度会与数据拟合程度发生变化。我们使用共轭梯度算法数值求解Tikhonov最小化条件。为了准确地计算正向问题的组成部分,我们使用了具有Sinc基函数的频域积分方程方法。积分方程法离散化了二维区域内声波方程的积分形式,并产生了一个两部分的矩阵问题,我们使用通用矩阵分解技术来求解格林函数和介质中的总场。我们成功地将非线性波形层析成像技术应用到了从超声波建模槽中获得的比例模型数据集。该数据集来自大多为平面层的环氧树脂模型,并且数据表现出弹性效应和其他复杂的波动现象。我们使用平滑的一维初始模型反转该数据集以用于模型中的横向变化,以证明非线性波形层析成像的有用性和有效性。 [参考:40]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号