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| 随钻中子伽马密度测井的双源距含氢指数校正方法 |
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张泉滢1,张锋1,2,王玉伟3,刘军涛1,贾文宝4,遆永周5,李静6
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(1.中国石油大学地球科学与技术学院,山东青岛 266580;2.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, 山东青岛 266071;3.新疆油田公司勘探公司,新疆克拉玛依 834000;4.南京航空航天大学材料科学与技术学院,江苏南京 210016;5.河南省科学院同位素研究所有限责任公司,河南郑州 450015;6.喀左县蒙古族高级中学古塔分校生物科组,辽宁朝阳 122300)
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| 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。 |
| 关键词: 可控中子源 双源距 密度 含氢指数 蒙特卡罗模拟 |
| DOI：10.3969/j.issn.1673-5005.2017.04.010 |
| 分类号::P 631.817 |
| 文献标识码:A |
| 基金项目:国家自然科学基金项目(41374125,9);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) |
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| Dual-spacing hydrogen index correction method for neutron gamma density measuring in LWD |
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ZHANG Quanying1, ZHANG Feng1,2, WANG Yuwei3, LIU Juntao1, JIA Wenbao4, TI Yongzhou5, LI Jing6
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(1.School of Geosciences in China University of Petroleum, Qingdao 266580, China;2.Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China;3.Exploration Company of Xinjiang Oilfield Company, Karamay 834000, China;4.College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;5.Zhengzhou Key Laboratory of Isotope Tracing and Detecting, Isotope Research Institute of Henan Academy of Sciences Company Limited, Zhengzhou 450015, China;6.Department of Biology, Guta Branch School of Mongolian Senior High School, Chaoyang 122300, China)
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| Abstract: |
| To resolve unstable density measurements using single detector hydrogen index correction calculation in neutron gamma density logging, a dual-spacing hydrogen index correction method is studied. The neutron and gamma ray distribution in different hydrogen index and formation conditions is simulated by a Monte Carlo method. A hydrogen index correction calculation model is established by the dual-spacing count rate ratio of capture gamma ray, hydrogen capture gamma ray and thermal neutron. The results of hydrogen index correction and the impact of caliper and salinity are compared. As a result, the accuracy in the density measurements after hydrogen index correction has improved significantly. Among them, the precision and accuracy from thermal neutron correction is the highest. The accuracy from hydrogen capture gamma correction is slightly higher than that of the capture gamma; on the contrary, the precision of hydrogen capture gamma is far less than that of the capture gamma and the thermal neutron. The error of dual-spacing hydrogen index correction increases with the increasing caliper and salinity. The results from thermal neutron correction are less sensitive to caliper and salinity, while the results from capture gamma and hydrogen capture gamma correction are considerably are on the opposite. The research provides correction methods for obtaining neutron gamma density accurately in LWD. |
| Key words: pulsed neutron source dual-space density hydrogen index Monte Carlo simulation |
