| 摘要: |
| 利用蒙特卡罗方法建立各种条件下的套管井计算模型，模拟相应的热中子时间谱,进而计算地层宏观吸收截 面。模拟结果表明:地层的宏观吸收截面随着孔隙度和含水饱和度的堉加而增加,且源距越小、地层水的矿化度和 泥质含最越高、套管的尺寸越大、仪器越捃中、俘获截面越卨的岩性地层条件下,地居的宏观吸收截面偵也越大;套 管壁厚和水泥环对地层宏观吸收截面没有影响，但套管堉越厚、水泥环厚度越小,热中子总计数越低。利用脉冲中 子测井数据确定地层含水饱和度时应对各种影响W素作相应的校正。 |
| 关键词: 脉冲中子-中子测井 含水饱和度 地层宏观吸收截面 蒙特卡罗模拟 中图分类号:P 631.817 文献标识码:A |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项H (40774058) |
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| Numerical simulation for influence factor of pulsed neutron-neutron logging |
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ZHANG Feng1,2,WANG Xin-guang1,2
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(1.College of Geo-Resources and Information in China University of Petroleum，Qingdao 266555, China ;2. CNPC Key Laboratory of Well Logging in China University of Petroleum, Qingdao 266555, Chirm)
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| Abstract: |
| The calculation models under the condition of different cased well situation were established by Monte Carlo method, and the relevant thermal neutron time spectrum was simulated. The formation macroscopic cross section was also calculated. The results show that the formation macroscopic cross section increases with porosity and water saturation increasing, and the thermal capture capability is powerful under the condition of small spacing, high salinity and shale content, large cased size, centraiized tool and high capture lithology formation. The thickness of the casing and the cement do not affect formation macroscopic absorption cross section, but the bigger the casing thickness and the smaller the cement thickness, the lower the total count of the thermal neutron. It must be corrected for different influential factor when the formation water saturation is determined by pulsed neutron logging data. |
| Key words: pulsed neutron-neutron logging water saturation formation macroscopic cross section Monte Carlo simulation |
