【作者】 任翔；

【导师】 葛良全；

【作者基本信息】 成都理工大学 ， 核技术及应用， 2010， 硕士

【摘要】 钻探是地质普查工作的重要方法,是发现和验证隐伏矿(化)体的经济、直接的手段。有些矿种(如铀矿)已大面积地开展带钻普查。传统的获得钻探结果,只有一种表示方法,即岩芯样化学分析。其工作流程为:由钻孔提取岩芯、劈芯取样、碎样缩分、化学分析。X射线荧光测井,即是将X射线荧光仪的探头置于钻孔或炮眼深处原位测定目标元素的含量或品位。常规的室内X射线荧光分析和地面现场X射线荧光分析,其被测对象都是干燥的粉末样品,或者是含有一定水分(一般小于10%)的土壤或岩石,且置于空气或真空环境中测量。由于X射线的透射深度有限,井液的存在不论对初级X射线还是次级X射线都产生吸收与散射。理论计算表明,15mm厚的水层可完全吸收10%铜含量的Cu的K系特征射线。虽然测井探管配有探头部分贴壁装置,但在X射线荧光测井工作中,井孔孔壁的局部变化是未知的,探测窗一侧与井壁是否在各测量点处于紧密接触状态也是未知的,探头和被测井壁之间仍会充有一层井液。在探头紧密贴井壁的前提下,进一步校正间距小于3毫米厚层井液对X荧光测井结果的影响。研究填充的井液的厚度变化对X射线荧光测量的影响并提出有效的校正技术,是保证原位X射线荧光测井分析精度、准确度的关键技术之一。本论文课题来源于:中国地质调查局地质调查项目:“X射线荧光测井技术研究”(项目编号:1212010706501)。论文从实用角度出发,通过理论分析与公式推导,并结合大量实验数据的比对。对X射线荧光测井测得谱线中信息进行提取与演算,实现对由井液引入的影响进行校正。论文取得了如下研究成果:(1)利用傅里叶本底扣除方法及高斯拟合求全能峰法预处理测得谱线数据,为井液校正提供了目标元素净峰面积计数数据。(2)理论研究与实验分析,结果表明:随着井液厚度增大,激发源散射峰的计数逐渐增加并逼近于一定值;目标元素特征峰的计数成指数规律减弱。(3)研究了探管与被测井壁间填充多种井液情况下,在探管与被测井壁间间距变化时,由于受一次以及多次散射射线增加的影响,探管铍窗中所含杂质被激发出的特征射线的照射量率随井液厚度增加也逐渐增加并逼近于一定值。(4)通过对以上规律的分析研究与实验验证,提出一种新的通过提取测得谱线中的信息进行井液影响校正的方法。经过实验验证:在经过井液厚度校正等一些列校正后,测井设备可以在充有井液以及对X射线荧光元素分析设备结构进行改变后,仍可实现较高以及高品位矿井中原位经行准确的元素分析。井液在0-3mm内变化时,对1%铜含量铜矿层产生的CuKa系特征射线峰面积相对变化小于10%。经模拟井壁样品检测表明,对Fe、Cu、Zn、Pb模拟井壁模型,除个别模型外,相对误差均在10%左右。更多还原

【Abstract】 Drilling is an important method of geological survey work is the discovery and validation of concealed deposits (of) that economic, direct means. Some minerals (eg uranium) has been carrying out large-scale survey with a drill. The traditional access to drilling results, only one representation that core samples for chemical analysis. The process is: extract from the drill core, split core sampling, crushing reduced hours, for chemical analysis. X-ray fluorescence logging, that is, X-ray fluorescence analyzer probe placed deep borehole drilling or in situ determination of the target element’s content or grade.Conventional X-ray fluorescence analysis of indoor and ground on-site X-ray fluorescence analysis, the measured objects are dry powder samples, or water containing a certain (generally less than 10%) of soil or rock, and placed in air or vacuum in the measurement. As the X-ray penetration depth is limited, regardless of the existence of well fluid to primary or secondary X-rays are produced X-ray absorption and scattering. Theoretical calculations show that, 15mm thick layer of water can absorb 10% of the total copper content of the Cu K-series characteristic radiation. Although the logging probe tube with a probe part of the attachment device, in X-ray fluorescence logging work, the well bore hole wall of the local change is unknown whether the detection window at the side with the wall at all measuring points in close contact state is unknown, still between the probe and the measured wall filled with a layer of well fluid. In the probe tightly to the wall under the premise of further correction gap of less than 3 mm thick layer of well fluid on the X-ray fluorescence logging results. Of fluid filled well on X-ray fluorescence thickness measurement of and propose effective correction technology to ensure in situ X-ray fluorescence analysis of the accuracy Logging, one of the key accuracy. Subject of this paper from: Geological Survey of China Geological Survey Project: "X-ray fluorescence logging technology" (item number: 1212010706501).Papers from a practical point of view, the formula derived by theoretical analysis and, combined with a large number of experimental data comparison. Logging on the X-ray fluorescence spectra measured in information extraction and calculus, to realize the impact of the introduction by the well fluid to correction. Paper made the following findings:(1) Background Subtraction Using Fourier and Gaussian fitting all-round peak demand measured spectral data pretreatment, as well liquid correction to provide a target data element of the net peak area counts.(2) Theoretical research and experimental analysis shows that: with the well fluid thickness increases, the count of excitation source scattering peaks gradually increase and approach to a certain value; target element characteristic peak counts less exponential law.(3) The probe tube and was filled with a variety of intramural Well Logging fluid case, is logging in the probe tube and the wall of pitch changes, and the multiple scattering due to an increase of radiation, beryllium window in the probe tube impurities were inspired by the characteristics of ray exposure rate increased with the well fluid thickness also increased gradually and approach to a certain value.(4) Above by the law of the analysis and experimental verification, a new spectrum measured by extracting the information in the influence of drilling fluidCorrection approach.Experimental results show: After the correction of drilling fluid and some out after the correction, logging equipment can be filled with well fluid as well as X-ray fluorescence elemental analysis device structure change, it can still achieve high and high grade mine in situ The line of accurate elemental analysis. Well within the fluid changes in the 0-3mm, the copper content of 1% copper layer lines characteristic CuKa radiation generated by the relative changes in peak area is less than 10%. The simulations show that the wall sample testing, on Fe, Cu, Zn, Pb analog wall model, except for individual models, the relative error of about 10%.更多还原