中子伽马测-渗-测工艺确定剩余油饱和度

比较了在测-渗-测工艺中,中子伽马与中子寿命测井在确定产层剩余油饱和度和水淹层的异同点以及解释结果方面的一致性。结果表明,中子伽马测井能够代替中子寿命测井,并显示出仪器结构简单、稳定性好、造价和测井费用低、易于推广应用等优点。     

硼中子寿命测井在低矿化度油藏开发中的研究及应用

硼中子寿命测井是在中子寿命测井改进中发展起来的一种适应低矿化度地层的动态监测新技术.通过采用"测-注-测"工艺获取地层剩余油信息,直观解释产层的油水比例关系.根据硼中子寿命测井资料实施措施的河68-24、通61-更40井取得了明显的增油效果.     

地层元素测井中中子-伽马能谱解析理论与方法

对在模型中进行地层元素中子伽马能谱测井实验和中子伽马谱解析方法进行了研究，即对非弹伽马谱与俘获伽马谱解析方法进行了研究。理论上推导出分别用非弹谱和俘获谱求出地层元素质量分数的公式。采用两谱联合分析及归一的方法，求出岩石骨架和孔隙流体整个地层中元素的质量分数。并在油田进行了实际应用，应用结果显示该方法是成功的     

地层元素测井中中子-伽马能谱解析理论和方法

对在模型中进行地层元素中子-伽马能谱测井实验中所得中子-伽马谱解析方法进行了研究,即对非弹伽马谱与俘获伽马谱解析方法进行了研究。理论上推导出分别用非弹谱和俘获谱求出地层元素质量分数的公式,得到了标准非弹伽马谱和标准俘获伽马谱,并在理论推导的基础上编制了相应的解谱程序。     

地层元素测井中子-伽马谱解析方法的实际应用

本文利用地层元素测井中子伽马谱的解析理论和解析方法，对两个油田的四口井连续获取的中子伽马谱，用自行设计与研制的软件系统，进行连续处理，获得H、C、O、Si、Ca、Fe、Mg、Al的质量分数随井深的变化曲线。同时，获得新C/O和新Ca/Si比值随井深的变化曲线，即测井曲线。随之利用新C/O比值求得有关井段地层的含油饱和度及划分水淹等级，而且利用元素质量分数求得有关地层的矿物含量，接着求得地层密度、宏观俘获截面和渗透率等。     

中子发生器在测井及其它领域中的应用

本文介绍了西安石油勘探仪器总厂研制的几种型号的中子发生器在碳氧比测井、中子寿命测井、可控源中于孔隙度测井、地球化学测井等领域中的应用现状,并简要介绍了其它领域中的应用情况,特别是中子辐照促使水产养殖增产的良好成果。     

钆示踪剂在中子寿命测井中的应用

建立了用钆作示踪剂的中子寿命测井方法,所选的井基本上是高产液、高含水,部分已因高含水停产.通过中子寿命测井,准确地确定了各井的主产水层位、具有产油潜力的层位和窜槽层位,为堵水、压裂等增产措施提供了可靠的依据,并取得了较好的地质效果.     

利用计算机提高中子测井曲线的纵向分辨率

为了解决薄油气层测井评价问题，有必要研究测井曲线纵向分辨率的处理方法。本文着重探讨了一种利用分辨率正匹法提高中子测井曲线纵向分辨率的方法。该方法的基本原理是：利用高分辨率近探测器记数率提高远探测器记数率的纵向分辨率，从而可全面提高中子曲线的纵向分辨率。经该高分辨率处理方法处理实际资料，表明该方法效果良好，可将中子曲线纵向分辨率提高到２０厘米。并且，该方法某些方面优于国外同类软件水平。     

井间钆示踪中子伽马能谱可动水饱和度监测方法

本发明为”井间钆示踪中子伽马能谱可动水饱和度监测方法”，其核心技术是在井间监测中用钆代替氚做示踪剂，将井口取样单一监测方法扩展为井下测井和井口取样综合监测方法，将监测目标从测定地层含水饱和度改变为测定地层可动水饱和度。在施工时先在注水井和采油井测量中子伽马基线，在注水井注入钆示踪剂，并测量中子伽马钆示踪注水剖面。此后，在相关采油井进行测井与井口取样双重监测，经综合分析分小层求出可动水饱和度井间分布。此项发明可用于注水开发油田高含水期监测可动水饱和度分布和划分水淹等级，进而估算剩油储量和有利区块。与现有的井间示踪方法相比，在厚层细分、薄层评价和用一种示踪剂实现多层监测等方面具有优势。     

随钻脉冲中子伽马密度测井最佳源距的优化设计

采用脉冲中子源进行密度测井,可避免传统密度测井放射性源对环境的影响,更加安全、环保。目前国内随钻脉冲中子伽马密度技术还处于起步阶段,随钻中子伽马密度仪参数优化设计是提高地层密度测量精度的关键。本研究通过由D-T中子源及2个伽马探测器组成的随钻中子伽马密度仪器,研究了源距对中子伽马密度测井的影响,通过灵敏度和计数比统计性进行源距优化设计,得出最佳短源距为25~35 cm,长源距为60~65 cm,研究结果为随钻脉冲中子伽马密度测井仪器研发提供技术支持。     

简单的n、γ分辨系统

本文介绍了一种简单的n、γ分辨系统和适用于该系统的探测器和脉冲形状甄别器,给出了系统参数、等效电子能量与n、γ分辨特性的关系,以及在~(241)Am-Be源、2.5MeV中子束和14MeV中子束情况下的n、γ时间分布。     

直径30 cm的等高圆柱形载钆液闪探测性能

载钆液闪探测器是高能物理及核物理实验中重要的粒子探测工具。通过研制得到了一台大体积的直径为30 cm等高圆柱形载钆液闪探测器,载钆液闪溶液的载钆量为0.5%wt;利用252Cf中子源进行了中子与γ分辨性能实验测试,结果表明,直径30 cm等高圆柱形载钆液闪的中子与γ分辨性能较差;利用飞行时间技术通过符合测量的方法,分别测量了中子与伽马分辨谱中的中子与γ信号的时间分布,两者峰位之间的时间差为2 ns;利用252Cf裂变电离室的裂变碎片信号作为开门信号,通过符合测量的方法,获得了直径30 cm等高圆柱形载钆液闪的中子俘获时间分布实验数据,中子俘获平均时间为11μs。对于较大体积条件下,载钆液闪的中子与γ分辨性能较差的物理现象,通过实验给出了合理解释和分析。     

A real-time neutron-gamma discriminator based on the support vector machine method for the time-of-fiight neutron spectrometer

A new neutron-gamma discriminator based on the support vector machine (SVM) method is proposed to improve the performance of the time-of-fiight neutron spectrometer. The neutron detector is an EJ-299-33 plastic scintillator with pulse-shape discrimination (PSD) property. The SVM algorithm is implemented in field programmable gate array (FPGA) to carry out the real-time sifting of neutrons in neutron-gamma mixed radiation fields. This study compares the ability of the pulse gradient analysis method and the SVM method. The results show that this SVM discriminator can provide a better discrimination accuracy of 99.1%. The accuracy and performance of the SVM discriminator based on FPGA have been evaluated in the experiments. It can get a figure of merit of 1.30.     

Neutron Radiation Effects on MOS Fets: Theory and Experiment

The effects of a pure neutron environment on Metal-Oxide-Semiconductor Field Effect Transistors (MOS-FET) is studied. A model for neutron-produced ionization in the oxide layer is presented. The energy partition between atomic displacement and electronic ionization processes in the nuclear scattering interaction is calculated and compared to the Lindhard model. It is shown that the neutron ionization causes a positive charge buildup in the oxide similar to a gamma ionization charge buildup. It is also shown that fast neutrons produce significant ionization energy which can become the major cause for ionization damage in a mixed neutron-gamma environment such as a nuclear blast. Specific experimental results are given for commercial and experimental MOS-FETS. The experimental technique used in achieving an almost pure neutron environment is described. Finally, an ionization dose equivalence for fast neutrons in SiO2 is given and compared to experimental values. This relation should prove useful in future studies of ionization damage in SiO2 subjected to a neutron-gamma environment.     

A real-time neutron-gamma discriminator based on the support vector machine method for the time-of-flight neutron spectrometer

A new neutron-gamma discriminator based on the support vector machine(SVM) method is proposed to improve the performance of the time-of-flight neutron spectrometer. The neutron detector is an EJ-299-33 plastic scintillator with pulse-shape discrimination(PSD) property. The SVM algorithm is implemented in field programmable gate array(FPGA) to carry out the real-time sifting of neutrons in neutron-gamma mixed radiation fields. This study compares the ability of the pulse gradient analysis method and the SVM method. The results show that this SVM discriminator can provide a better discrimination accuracy of 99.1%. The accuracy and performance of the SVM discriminator based on FPGA have been evaluated in the experiments. It can get a figure of merit of 1.30.     

Effects of multistress aging (radiation, thermal, electrical) onpolypropylene

Capacitor-grade polypropylene films were aged under multiple stresses (electrical, thermal, and radiation). The aging experiments were performed for both singular and simultaneous combined stresses. The polypropylene was exposed to combined neutron-gamma radiation with a total dose of 1.6×10⁶ rad, electrical stress at 40 V _rms/μm, and thermal stress at 90°C. Post-aging diagnostics consisting of electrical, mechanical, physical and chemical characterization were carried out to identify degradation mechanisms for polypropylene films under multifactor stress aging. The most pronounced changes were observed in the mechanical properties of the film. Significant decrease in elongation at break and tensile strength proved deterioration of the polypropylene under combined neutron-gamma radiation. This decrease was caused by chain-scission of the polypropylene molecules. The temperature stress had an opposite effect, causing an increase in the above-mentioned properties and offsetting, therefore, the negative effect of radiation. Although changes were observed in the electrical properties, they were not as significant as those for the mechanical characteristics. It can be concluded, that the failure mechanism of the electrical insulation under multistress aging conditions could be a mechanical failure of the material, rather than direct homogeneous decay in the dielectric strength or thermal breakdown of the polymer     

飞行时间效应对含氢系统瞬发中子衰减常数测量的影响

为实验获取含氢介质核系统的瞬发中子衰减常数,对中子飞行时间效应的影响进行了数值计算,并设计实验来验证分析结论。结果表明,当中子的飞行时间效应显著时,测量结果的准确性将受到影响;对热中子灵敏的6Li玻璃探测器,通过减小探测距离和屏蔽低能中子可降低中子飞行时间效应的影响。     

测量反应堆快中子注量率的电流型宽禁带半导体探测器设计

为解决强流混合场快中子注量率实时测量的难题,本文基于反冲质子法,以耐辐照性能强、噪声低的半绝缘型（SI）GaN半导体材料为基础,采用带石墨平衡体及聚乙烯转换靶的并联结构,设计补偿式电流型探测器的方案,有效地降低了γ射线灵敏度。利用该探测器测量了西安脉冲堆1#径向孔道内混合场的快中子注量率,其结果与已有测量结果符合较好,验证了该方案的可行性。