相位感应测井仪器设计及其信号处理研究

【作者】 刘智涌；

【导师】 聂在平；

【作者基本信息】 电子科技大学 ， 电磁场与微波技术， 2003， 硕士

【摘要】 电法测井经过七十多年的发展，现已成为一门独立的学科。从最初的自然电位测井，发展到了感应测井和阵列感应测井。但是，感应测井和阵列感应测井在仪器设计和制造时存在直耦对消问题，已成为感应测井仪器发展的瓶颈。因此，在感应测井基础上，提出了只测量相位差而非感应电动势的相位感应测井仪，避开了在感应测井中非常棘手的直耦对消问题，大大降低了仪器研发的难度。测井仪器是在井下高温高压的环境中工作的，为了保护仪器内部电子线路和测量不受井眼条件的影响，在仪器设计过程中必须考虑诸如玻璃钢外壳和仪器内部注油等结构和措施来隔离外界环境，平衡压力。这些附加结构和措施会对测量结果产生哪些影响必须详细考察。同时，在测井工程中，径向探测深度和纵向分辨率是评价测井系统优劣的主要指标，为了评价这种仪器的性能，也必须对其径向探测深度和纵向分层能力做一个讨论。因为数值模式匹配法（NMM）是一种精确高效的半解析半数值方法，特别适用于在水平和纵向任意分层结构的分析，是正演分析的首选。本文就利用数值模式匹配法计算各种情况下相位感应测井仪的响应，考察各种仪器结构和外部环境对测量结果的影响，并且讨论各种条件下相位感应测井仪的径向和纵向特性，探讨了一种用均匀池水刻度仪器的可行性。在正演考察仪器设计的各种方案的之后，本文还就相位感应测井仪测量信号现场处理进行了讨论。现场处理分为两部分：井眼校正版图对井眼进行校正以减小井眼条件对测量结果的影响；自适应反褶积对围岩效应进行校正，以提高仪器测井曲线的纵向分辨率。而本文重点研究了后者。反褶积对测量结果进行自适应反褶积处理，提高了测井曲线的纵向分辨率。更多还原

【Abstract】 After over 70 years’ development, electric logging has become an independent subject. Developed from the spontaneous potential logging tool, induction logging tool and Array Induction Tool (AIT) are popular today. But how to eliminate the influence of direct coupling signal is the hardest problem when using the induction logging tool and AIT. Based on induction logging , Phasor induction logging tool is studied to avoid the above problem, which makes the apparatus’s research and manufacturing more easier. In order to protect circuit and keep precision of the measure, in the high temperature and pressure environment which the tool works, we have to design accessory such as Glass Reinforce Polymer (GRP) hull and inject oil. In well logging radial investigation depth and vertical resolution are criterions for apparatus application, so we discuss the performance of vertical and radial direction of the phasor induction logging tool. Numerical Mode-Matching (NMM) predigests a calculation of two-dimensional as using an analytic expression of one-dimensional counting the other-dimensional, and the efficiency is improved dramatically. So Numerical Mode-Matching (NMM) can be used as computer aid explanation for logging tool. With NMM, we calculate a lots of responses of different conditions, discuss the vertical and radial direction of the phasor induction logging tool, what’s more, discuss a new calibration.After the introduction of the design of the phasor induction logging tool, we discuss on-sit processing of the logging. On-sit processing include two steps: borehole correction charts and adaptive deconvolution. Borehole correction charts are used as correction to avoid the influence of borehole. We put the emphasis on the adaptive deconvolution that can correct shoulder beds. Based on theory of electromagnetic propagation, geometric factor and filter window length are used to solve deconvolution factor. The vertical resolution can be improved after adaptive deconvolution.更多还原