X射线密度仪射线出射口角度优化研究  

Influence of X-Ray Source Emission Angle on Logging Performance

作　　者：向阳佳琪 范继林 张琼 金亚 张全文[2] 谢昱北 XIANG Yangjiaqi;FAN Jilin;ZHANG Qiong;JIN Ya;ZHANG Quanwen;XIE Yubei(School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu,Sichuan 611731,China;Technology Research Institute,CNOOC Oilfield Services Limited,Langfang,Hebei 065000,China)

机构地区：[1]电子科技大学自动化工程学院,四川成都611731 [2]中海油田服务股份有限公司油田技术研究院,河北廊坊065000

出　　处：《测井技术》2024年第6期772-780,788,共10页Well Logging Technology

基　　金：国家自然科学基金“基于X射线成像的油气环保勘探技术新理论新方法研究”(U23B20151)。

摘　　要：在油气勘探技术持续进步与发展的背景下,可控X射线密度测井仪器设计和测量方法受到广泛关注。在超细X射线测井仪的基础上,改变X射线源的发射角度,利用蒙特卡罗方法进行模拟,根据探测效率、密度测量灵敏度、探测深度等指标,确定X射线源最佳发射角度。在此基础上,模拟实际地层环境对选取的X射线源发射角度进行地层密度与光电吸收截面指数(Pe)的测量准度验证,并将选取最佳发射角度后的超细X射线测井仪器与伽马测井仪器进行对比分析。研究结果表明,将X射线源发射角度设置为135°,近探测器具有最高密度测量灵敏度;仪器探测深度为6 cm,可以使超细X射线测井仪器具有最佳测井效果。在发射角度为135°的情况下,超细X射线测井仪器在灰岩地层中裸眼情况下测量的密度准确度为0.0041 g/cm^(3),Pe准确度为0.0139。此外,在轻泥饼条件下,选取最佳发射角度后的超细X射线仪器的密度测量误差下降0.0024 g/cm^(3),Pe测量误差下降0.0262。利用该优化方法,测量准确度有较大的提升。Against the backdrop of continuous progress and development in oil and gas exploration technology,the design and measurement methods of controllable X-ray density logging tools have received widespread attention.On the basis of the ultra-slim X-ray logging tool,the emission angle of the X-ray source is changed,and Monte Carlo simulation is used to determine the optimal emission angle of the X-ray source based on detection efficiency,density measurement sensitivity,detection depth and other indicators.On this basis,simulate the actual geological environment to verify the measurement accuracy of formation density and Pe for the selected X-ray source emission angle,and compare and analyze the ultra-slim X-ray logging tool with the gamma logging tool after selecting the optimal emission angle.The research results show that setting the X-ray source emission angle to 135°,the near detector has the highest density measurement sensitivity,and the instrument detection depth is 6 cm,which can make the ultra-slim X-ray logging instrument have the best logging effect.At an emission angle of 135°,the density accuracy measured by the ultra-slim X-ray logging tool in the limestone formation under naked eye conditions is 0.0041 g/cm^(3),and the Pe accuracy is 0.0139.In addition,under the condition of light mud cake,the density measurement error of the ultra-slim X-ray tool after selecting the optimal emission angle decreased by 0.0024 g/cm^(3),and the Pe measurement error decreased by 0.0262.Using this optimization method,the measurement accuracy is greatly improved.

关 键 词：X射线密度测井 X射线源发射角度 地层密度计算 地层光电吸收截面指数(Pe)计算 蒙特卡罗方法 

分 类 号：P631.84[天文地球—地质矿产勘探]