【作者】 秦超飞；

【导师】 汤彬；

【作者基本信息】 东华理工大学 ， 核技术及应用， 2012， 硕士

【摘要】 自然γ能谱测井，通过研究地层中天然放射性核素产生的γ射线的能谱，实现地层中放射性核素的定性解释和放射性核素含量的定量解释，是一种比较先进的定性与定量解释方法。本文通过在传统能谱解析技术中引入总量型γ分层解释理论，形成新的能谱型γ分层解释方法。而换算系数和特征参数是能谱型γ分层解释方法的两个重要参数，本文针对换算系数的求取方法进行研究。参考总量γ测井换算系数和传统γ能谱测井换算系数的求取方法，本文尝试在标准饱和模型上利用特征峰区的计数率求取换算系数，并且通过对实测数据的处理，对该方法进行验证。本文先后采用HPGe探测器和LaBr3探测器，在标准饱和模型上开展γ能谱测井实验。实验中使用的HPGe探测器具有较好谱漂自校功能，可以对特征峰区进行准确地划分，且具有较好的能量分辨本领，可以选择的特征峰区较多，因此，HPGe探测器实测数据的解释效果较好，主要核素的含量解释误差都在5%以内。这一方面验证了在标准模型上利用特征峰区求取全谱刻度系数具有一定的可行性，另一方面，也证明了能谱型γ测井在核素定量解释方面的优越性。对于LaBr3探测器，由于是首次在能谱测井使用该类型仪器，因此实测数据存在谱线漂移等一些问题，本文通过对LaBr3探测器实测能谱特点的分析，筛选出可用的模型数据，及可用的特征峰区。实测数据的处理结果显示，主要核素的解释误差在10%以内，从而验证了LaBr3探测器应用于γ能谱的可行性。在数据处理过程中，我们使用了射线能量小于1MeV的特征峰区，并且将康普顿散射的贡献也计算在内，同样取得了良好的计算效果。总的来说，在模型实测法中，根据实测能谱的特点，选择合适的特征峰区求取换算系数是可行的，并且可以将核素解释含量的误差控制在较小的范围内。更多还原

【Abstract】 Natural γ-ray spectrum logging is an advanced qualitative and quantitativeinterpretation method, which used to tell the nature of the rock and the content ofradioactive nuclide in the mineral, by studying of natural gamma ray spectrum.In this article, we are trying to form a new subdivision interpretation technology forenergy spectrum γ-ray logging, by introducing the subdivision interpretation methods ofγ-ray logging into the traditional energy spectrum analysis methods. The scale factors andthe characteristic parameter are two most important parameter in subdivisioninterpretation technology for energy spectrum γ-ray logging. In this article, we focus onthe method of finding scale factors.Referring to the calculating method of scale factor in the subdivision interpretationmethods of γ-ray logging and traditional natural γ-ray spectrum logging, we are trying tostudy the calculating method of the scale factor, and prove it by the analysis of actualmeasurement data.During our γ-ray spectrum logging test, HPGe detector and LaBr3detector wereused on standard model. The HPGe detector has a good performance of spectrumstabilization technology as well as perfect energy resolving power, so the characteristicpeaks could be divided accurately and much more characteristic peaks can be selected.As a result, We get a satisfactory result of actual measurement data, the relative errors ofexplain content for main element are under5percent. On one hand, it is feasible to getthe scale factors through standard model, on the other hand, the advantage of naturalγ-ray spectrum logging is proved also.Because it is the first time to use LaBr3detector in γ-ray spectrum logging, there aresome problems exist such as spectral shift. Through the analysis of feature of actualmeasurement data, we select some available data as well as the characteristic peaks. Theresults prove the feasibility of LaBr3detector in γ-ray spectrum logging, for the relativeerror of explain content for main element are under10percent.During the data analysis, the characteristic peaks were used for the radial energyunder1MeV, the contribution of compton effect were calculated also, a satisfactoryresult still arrived.Generally speaking, on standard model. the scale factor can be obtained bychoosing proper characteristic peaks according to the feature of actual measurement data,as well as the relative error of explain content can be very small.更多还原