【作者】 孙威；

【导师】 单文文；

【作者基本信息】 中国科学院研究生院（渗流流体力学研究所） ， 流体力学， 2004， 硕士

【摘要】 目前现有的核磁共振仪器体积大、重量大、对环境要求高，不适合油田现场的使用。因此有必要研制重量轻、体积小、对工作环境要求不高、功能简化，而适合油田现场使用的专用核磁共振仪器。 核磁共振中的磁体设计有许多方案，但是要使磁体体积小、重量轻、均匀区大、稳定性好，将面临一系列的问题。而这些问题的解决主要依赖于电磁场计算。本文首先阐述这些问题，然后对方案进行优化分析计算，从中找出一个最佳的解决方案。 本文通过经验公式初步确定出磁体的各部分尺寸，然后经过2D、3D的有限元分析、优化和修正，以达到实际要求，把有限元磁场分析数值计算有效地应用于磁场设计中，作了一次有益的尝试。 利用数值计算设计出来的永磁磁体研制出来的便携式核磁共振岩屑分析仪对多块岩心进行NMR信号采集，近一步验证了本设计的正确性。并通过在二连浩特油田一口探井开展了磁共振分析仪现场应用效果研究。在钻井现场，使用便携式核磁共振岩样分析仪，对现场取心样、井壁取心样和岩屑进行快速测量，定量获得了总孔隙度、渗透率、可动流体孔隙度及含油饱和度等四项参数，但对井壁取心样的快速测量，仅对含油饱和度一项参数进行测试。将测量结果与核磁共振测井结果及相应井段取心常规分析得到的结果进行比较和分析。 得到以下结论：核磁岩屑录井得到的孔隙度、渗透率及可动流体百分数结果与同深度的核磁共振测井得到的结果符合较好，在无法进行核磁共振测井的油田区块，可以将核磁岩屑录井作为现场核磁共振测井的一种替代补充技术，在一定程度上降低勘探开发成本，丰富勘探开发手段。更多还原

【Abstract】 The current NMR instruments are always large, weighty and strict to circumstance, so they are unfit for on- site application of oil field. It is necessary to design an appropriative NMR instrument used in oil field with good property, such as, small, stable, affable to circumstance and easy to operate.There are many ways of magnet design in Nuclear Magnetic Resonance. However, it will bring a series of problems to make magnet small, light, stable and having larger uniformity area . Solution of these problems relies on the computing of electromagnetism field .In this article ,we first expatiate on the problems, then optimize different ways of design ,and finally choose the best one.In this paper, size of parts of magnet derives primarily from the empirical formula, then the 2D and 3D finite element analysis, optimization and correction was done to achieve the goal of reality. Numerical calculation of finite element analysis of magnet was applied effectively to design magnet. It is a significant try.Utilizing the portable NMR cuttings analyzer, which is made up with the permanent magnet designed by numerical calculation, collection of many core’s NMR signal further confirmed correctness of this design. NMR analyzer was applied on Er Lian Hao Te oil field. On the site of field ,using the portable NMR coreanalyzer ,MAGNET-2000, the fast measurement to the on-site core, wall core of a well and cuttings have been done. The porosity, permeability and mobile fluid saturation and oil saturation was measured quantificationally. As to the wall care of a well, only oil saturation was measured. Result was analyzed and compared with that of NMR logging and the conventional method.Conclusion: Result of Porosity, permeability, and mobile fluid percent from NMR cuttings analyzer is fit well with that of NMR logging at the same deep plot. On some oil field where NMR logging can’t be developed, the NMR cuttings analyzer is a good substitute . In some aspect, the analyzer reduce cost of exploration and enrich the exploration method.更多还原