多分量色散电磁传播测井三维正演和快速反演理论研究

It has been documented that traditional electrical well-logging are facing two major limitations: 1) the inability of traditional measurements to detect dual parameters (both resistivity and dielectric constant) electromagnetic properties of the anisotropy and dispersion; 2) poor real-time capability and insufficient robustness control in current inversion methods that confines its widespread use in the actual logging data. In this project we proposed a new-generation electromagnetic propagation well-logging, i.e. multi-component dispersion electromagnetic propagation logging (MDEMPL) to overcome above mentioned limitations. We will develop the three-dimensions (3D) forward-modeling and fast-inversion theory including response characteristics analysis and data inversion methods for MDEMPL in anisotropy and dispersion inhomogeneous formation. The step-by-step research scheme is described as the following:.1 To construct a response characteristics analysis method by modeling the logging response in arbitrary inhomogeneous 3D anisotropy and dispersion medial with the multi-resolution domain method in electromagnetic. This method will lay out the foundation to achieve successful implementation of investigational characteristics analysis and fast inversion..2 To establish an investigational characteristics analysis method by extracting the response functions of arbitrary inhomogeneous 3D anisotropy and dispersion medial based on an integral equation with numerical methods..3 To achieve a high-resolution matching method of logging curves by designing the multi-input and mutil-output deconvolution technique. A multi-resolution artificial intelligence technique with artificial neural network theory and Support Vector Machine (SVM) will be adopted. These two methods will be used to develop an inversion without forward modeling to enhance inversion efficiency..4 To address dynamic methods of inverse problems with the symplectic algorithms in solving evolution equation in Hamiltonian form. This method could be applied to multi-parameters and nonlinear inverse problems of MDEMPL to obtain more robustness and high-precision results..The successful implementation of MDEMPL will 1) enhance the omnidirectional exploring ability of dielectric constant and resistivity in complexity layered anisotropy and dispersion medial; 2) provide the effective electrical well-logging measurements for more complicated petrophysical formation evaluation in the thinly laminated shale-sands layer and the carbonate and heavy oil reservoirs. The overall goal of the proposed study is to advance the development of new generation techniques in electrical well-logging.

针对传统电法测井对地层电阻率和介电常数各向异性和色散特性探测不足问题，以及反演方法在处理实际资料存在着实时性差和精度低的难题，提出多分量色散电磁传播测井新方法。基于各向异性色散地层模型，建立包括响应特征、探测特性分析和资料快速处理的正反演理论：1.应用时域多分辨率自适应方法建立响应特征分析体系，为探测特性分析和快速反演奠定基础。2.利用积分方程和数值方法提取非均质各向异性色散地层仪器的响应函数，建立探测特性的分析体系。3.设计多输入多输出反褶积算法，建立测井曲线高分辨率处理方法；建立基于支持向量机的多分辨率人工智能方法，实现测井资料无正演快速反演。4.应用哈密顿系统的辛几何算法，建立高精度求解多参数和非线性反问题的动力学方法。项目的完成可以实现层状各向异性色散地层电阻率和介电常数高分辨率全向探测，为薄交互层、碳酸盐和重油油储疑难地层评价提供更有效的电法测井手段，推动新一代电法测井技术发展。

本项目旨在发展一种多频、多源距的多分量色散电磁传播测井方法，探讨其快速有效的正、反演理论框架，实现复杂测井环境下地层电阻率和介电常数各向异性和色散特性的高分辨率全向探测。完成主要研究内容和取得成果有：. 第一，响应特征分析方法研究：针对MDEMPL正演问题的特点，建立了基于矩量法电磁场积分方程理论计算模型；提出了均匀单轴各向异性介质MDEMPL广义等效网络模型快速正演计算方法。对于非均匀单轴各向异性色散介质，开发了基于伸缩坐标形式PML和Z变换技术的FDTD计算方法。. 第二，多分量色散电磁传播测井方法的原理研究：在响应特征研究的基础上深入开展MDEMPL原理研究，优化仪器结构参数，定量建立各向异性色散地层测井解释模型。初步建立多频、多源距多分量电磁传播测井仪器结构和参数优化选择模型，频率范围在1MHz-80MHz之间，源距在0.3m到1.8m之间，两种9分量测量方案，一种和多分量感应测井对应9个分量幅度比和相位差测量，一种经过适当组合和仪器方位角无关的9个分量幅度比和相位差测量；建立了基于介质极化的Debye 模型和砂岩和泥岩薄交互层的介电常数和电阻率宏观单轴各向异性色散介质模型。. 第三，电阻率和介电常数视值提取方法研究：利用均匀各向异性色散介质响应公式将MDEMPL 测量值相位差和幅度比等效转换电阻率和介电常数。采用波分解方法将均匀单轴各向异性介质MDEMPL响应分解为四种类型电磁波非线性组合，推导了四种类型电磁波对于地层参数和仪器参数的导数公式，在此基础上建立了由多频、多源距和多分量幅度比和相位差测量量提取地层水平介电常数、电阻率和垂直介电常数和电阻率以及仪器倾角和方位角高斯-牛顿反演方法，并开发了相应计算程序。. 第四，反问题动力学方法预研究：研究将哈密顿系统的辛几何算法应用于MDEMPL反问题具体实现方案。分两步建立了反问题动力学方法，将反演问题等效为用哈密顿系统描述动力学系统；构造了反演问题动力学系统的辛几何算法。. 通过上述研究，多频、多源距的多分量色散电磁传播测井方法将使得复杂测井环境下地层电阻率和介电常数各向异性和色散特性的高分辨率全向探测成为可能，多分量色散电磁传播测井使得随钻电磁传播测井和多分量感应测井合流成为新一代电法测井方法，提供更丰富、更可提取反映复杂测井环境地层电磁参数信息。