随钻中子伽马密度测井的双源距含氢指数校正方法

发布时间：2018-02-26 12:16

本文关键词： 可控中子源双源距密度含氢指数蒙特卡罗模拟　出处：《中国石油大学学报(自然科学版)》2017年04期 　论文类型：期刊论文

【摘要】：针对中子伽马密度测井中利用单探测器信息进行含氢指数校正计算密度结果的不稳定问题,开展双源距含氢指数校正方法研究;采用蒙特卡罗方法模拟热中子、伽马分布与密度和含氢指数的响应规律,建立热中子、俘获伽马以及氢俘获伽马计数比进行含氢指数校正的密度计算模型,对比不同粒子含氢指数校正效果以及井径、矿化度的影响。模拟结果表明:含氢指数校正后密度准确度明显改善;其中,热中子含氢指数校正后的密度精度和准确度最高,氢俘获校正密度准确度略高于俘获伽马,但其密度精度远小于热中子和俘获伽马。双源距含氢指数校正密度误差随着井径和地层水矿化度的增大而增大;其中,热中子校正受井径和矿化度影响最小,氢俘获和总俘获伽马校正方法受影响较大。研究结果为随钻测井准确计算中子伽马密度提供了校正方法。
[Abstract]:In order to solve the unstable problem of using single detector information to correct the density of hydrogen in neutron gamma density logging, the double source distance hydrogen index correction method is studied, and the Monte Carlo method is used to simulate thermal neutron. Based on the response law of gamma distribution to density and hydrogen content index, a density calculation model of thermal neutron, capture gamma and hydrogen capture gamma counting ratio for correction of hydrogen content index is established, and the correction effect of hydrogen content index and well diameter of different particles are compared. The simulation results show that the density accuracy is obviously improved after the correction of hydrogen content index, in which the density accuracy and accuracy of thermal neutron hydrogen index correction are the highest, and the accuracy of hydrogen capture correction density is slightly higher than that of capture gamma ray. But its density accuracy is much less than thermal neutron and capture gamma. The correction density error of double source distance hydrogen content index increases with the increase of well diameter and formation water salinity, in which thermal neutron correction is least affected by well diameter and salinity. Hydrogen capture and total capture gamma correction methods are greatly affected, and the results provide a correction method for accurate calculation of neutron gamma density by logging while drilling.
【作者单位】：中国石油大学地球科学与技术学院;海洋国家实验室海洋矿产资源评价与探测技术功能实验室;新疆油田公司勘探公司;南京航空航天大学材料科学与技术学院;河南省科学院同位素研究所有限责任公司;喀左县蒙古族高级中学古塔分校生物科组;
【基金】：国家自然科学基金项目(41374125,41574119) 国家重大油气专项(2017ZX05019005-004) 中央高校基本科研业务费专项(14CX05011A,15CX06008A)
【分类号】：P631.817

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