摘要
为满足复杂岩性储层评价需要,在中国首次研制了脉冲中子地层元素测井仪,研究了测井资料处理方法并开发了配套软件。以PNST脉冲中子全谱测井仪为基础,通过优化设计传感器结构和脉冲时序、改进中子发生器、应用数字脉冲幅度分析技术,研制了PNST-E脉冲中子地层元素测井仪。实测能谱中元素特征峰清晰,2支测井仪的能谱相互一致,相关系数达0.99。经7口地层元素模型井实测能谱校验模型,针对反应截面较高的主要造岩元素,利用MCNP数值模拟获得了9种元素非弹、17种元素俘获标准谱及这些元素的相对灵敏度因子。资料处理软件采用约束解谱法求出非弹、俘获元素产额,应用氧化物闭合模型计算出Si、Ca、S、Fe、Ti、Gd、K、Na、Mg、Al等元素干重和总有机碳含量(TOC),解释矿物组分和骨架参数。在7口模型井中实测Si、Ca、S、Fe、Ti等元素干重的最大误差是2.4%。现场试验PNST-E测井结果与取心数据相符,与国外同类技术测井结果相符。
To evaluate the complex lithology reservoirs, a pulsed neutron spectroscopy tool for formation elements logging is developed for the first time in China. Processing methods for its logging data are studied and a complete set of matched software is designed. On the basis of the PNST tool, the PNST-E pulsed neutron formation elements logging tool is constructed, through optimizing the sensor structure and pulse timing, improving the pulsed neutron generator and employing digital pulse amplitude analyzers. Elemental peaks are distinct in the measured spectra. Two spectra measured by different tools are consistent with each other, with the correlation coefficient of 0. 99. A set of elemental standard spectra, which include nine of inelastic and seventeen of capture spectra for each frequently encountered element, and their relative sensitivity factors are obtained through MCNP numerical simulation, using the simulation model which has been verified by comparing the simulated spectra with the recorded by a PNST-E tool in seven calibration wells of typical lithology. In elastic and capture elemental yields can be derived from constrained unfolding corresponding spectra, with the data processing software. Dry-weight concentrations of Si, Ca, S, Fe, Ti, Gd, K, Na, Mg and Al elements, as well as TOC can be calculated by applying the oxide-closure model, and the mineralogical composition and rock matrix parameters can be interpreted with the same software. The maximum error of measured dry-weights of Si, Ca, S, Fe and Ti elements is 2.4% in the seven lithology calibration wells. PNST-E logging data from field test are consistent with the core data and the results fromsimilar foreign logging technology.
出处
《测井技术》
CAS
CSCD
2015年第4期395-404,421,共11页
Well Logging Technology
基金
国家科技重大专项大型油气田及煤层气开发(2011ZX05014)
关键词
地层元素测井
脉冲中子测井
测井仪
能谱
标准谱
元素含量
矿物组分
总有机碳含量
formation elementsstandard spectrum
carbonlogging
pulsed neutron logging
logging tool
energy spectrum
elemental concentration
mineralogical composition
total organic
