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公开(公告)号：US4972082A
公开(公告)日：1990-11-20
申请号：US324776
申请日：1989-03-16
IPC分类号： G01V5/10
摘要： The porosity of an earth formation is derived in a plused neutron logging tool by use of a directionalized and borehole-shielded eptithermal neutron detector array and by processing detector count rate measurements of the epithermal neutron die-away curve in accordance with a multi-parameter fit to obtain as one parameter the epithermal neutron decay time of the formation and as a second parameter an indication of detector standoff (environmental) effects. The multi-parameter fitting procedure separates the formation and standoff effects on the measured count vs time curve, and yields a decay time measurement that is primarily representative of formation porosity and substantially free of environmental effects. To enhance count rate statistics, the neutron source and one or more of the epithermal neutron detector may be located at the same depth in the borehole. The neutron burst centroid is monitored an used to define a fiducial window for processing the die-way curve data.
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公开(公告)号：US5420422A
公开(公告)日：1995-05-30
申请号：US179787
申请日：1994-01-11
申请人： William A. Loomis
发明人： William A. Loomis
IPC分类号： G01V5/10
CPC分类号： G01V5/107
摘要： The first and second moments of an epithermal neutron slowing down time curve are determined and are combined in accordance with a predetermined empirical relationship to derive a raw measurement of the porosity of an earth formation surrounding a borehole. The raw porosity value is then combined with the second moment in accordance with further predetermined empirical relationships to derive a standoff measurement and a standoff-correction factor to be applied to the raw porosity measurement to produce a standoff-corrected porosity measurement. Where the raw porosity value changes appreciably from depth level to depth level, a differential spatial filter is applied to the raw porosity measurement and to the standoff-correction factor to provide a more precise standoff-corrected porosity measurement.
摘要翻译： 确定超热中子减速时间曲线的第一和第二时刻，并根据预定的经验关系进行组合，以得出围绕钻孔的地层的孔隙率的原始测量。 然后根据进一步预定的经验关系将原始孔隙度值与第二时刻相结合，以得出待应用于原始孔隙度测量的间隔测量和间隔校正因子，以产生间隔校正孔隙度测量。 当原始孔隙度值从深度水平深度变化到深度水平时，将差分空间滤波器应用于原始孔隙度测量和间隔校正因子，以提供更精确的间隔校正孔隙度测量。
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公开(公告)号：US5539225A
公开(公告)日：1996-07-23
申请号：US307894
申请日：1994-09-16
申请人： William A. Loomis , Kenneth E. Stephenson , Jerome A. Truax , Wolfgang P. Ziegler , S. Zema Chowdhuri , Benoit Couet , Michael L. Evans , Paul Albats , Bradley A. Roscoe , Jacques M. Holenka , Keith A. Moriarty , William R. Sloan
发明人： William A. Loomis , Kenneth E. Stephenson , Jerome A. Truax , Wolfgang P. Ziegler , S. Zema Chowdhuri , Benoit Couet , Michael L. Evans , Paul Albats , Bradley A. Roscoe , Jacques M. Holenka , Keith A. Moriarty , William R. Sloan
IPC分类号： G01V5/10
摘要： Measurement-while-drilling apparatus includes a 14 MeV neutron accelerator, a near-spaced neutron detector which primarily senses source neutrons and whose output is proportional to source strength, one or more intermediately-spaced epithermal neutron detectors eccentered against the drill collar wall and primarily responsive to formation hydrogen concentration, and a third far-spaced radiation detector, either gamma ray or neutron, primarily responsive to formation density. The intermediately-spaced and far-spaced detector outputs, normalized by the near-spaced detector output, are combined to provide measurements of porosity, density and lithology and to detect gas. A thermal neutron detector and/or a gamma ray detector may also be provided at intermediate spacings to provide additional information of interest, such as standoff measurements and spectral analysis of formation composition. Tool outputs are related to the angular or azimuthal orientation of the measurement apparatus in the borehole.
摘要翻译： 测量同时钻探装置包括14MeV中子加速器，近距离中子探测器，其主要感测源中子并且其输出与源强度成比例，一个或多个间隔开的超热中子检测器偏心于钻铤壁，主要 响应于地层氢浓度，以及第三远距离辐射探测器，伽马射线或中子，主要响应地层密度。 通过近距离检测器输出归一化的中间间隔和远距离的检测器输出被组合以提供孔隙度，密度和岩性的测量并检测气体。 还可以以中间间隔提供热中子检测器和/或γ射线检测器以提供感兴趣的附加信息，例如间隔测量和地层组成的光谱分析。 刀具输出与钻孔中测量装置的角度或方位角方向有关。
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4.发明授权Methods and apparatus for calibration of BGO scintillator gamma ray energy spectra 失效用于校准BGO闪烁体γ射线能谱的方法和装置
公开(公告)号：US5171986A
公开(公告)日：1992-12-15
申请号：US767177
申请日：1991-09-27
摘要： The energy-to-channel response of a bismuth germanate scintillator (BGO) gamma ray spectra measurement system is calibrated by use of the 10.2 MeV gamma ray peak originating from epithermal neutron capture within the BGO crystal as a calibration reference line. The 10.2 MeV peak is located by successively fitting the detected spectrum to the combination of a gaussian-shaped gamma ray peak and an exponentially-shaped background, beginning at the upper end of the spectrum and successively sliding the fitting window downwards until the peak is reached. Once the 10.2 MeV peak has been located, the spectral gain is adjusted to shift the peak to an assigned calibration channel location adjacent the upper end of the overall spectral window.
摘要翻译： 锗酸铋闪烁体（BGO）伽马射线光谱测量系统的能量对通道响应通过使用源自BGO晶体内的超热中子俘获的10.2MeV伽马射线峰值作为校准参考线进行校准。 10.2 MeV峰位置是通过将检测到的光谱连续地拟合到高斯形γ射线峰和指数形背景的组合，从光谱的上端开始，并将拟合窗口向下滑动直到达到峰值 。 一旦定位了10.2MeV峰值，则调整光谱增益以将峰值移动到与整个光谱窗口的上端相邻的分配的校准通道位置。
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公开(公告)号：USRE36012E
公开(公告)日：1998-12-29
申请号：US710997
申请日：1996-09-25
申请人： William A. Loomis , Kenneth E. Stephenson , Jerome A. Truax , Wolfgang P. Ziegler , S. Zema Chowdhuri , Benoit Couet , Michael L. Evans , Paul Albats , Bradley A. Roscoe , Jacques M. Holenka , Keith A. Moriarty , William R. Sloan
发明人： William A. Loomis , Kenneth E. Stephenson , Jerome A. Truax , Wolfgang P. Ziegler , S. Zema Chowdhuri , Benoit Couet , Michael L. Evans , Paul Albats , Bradley A. Roscoe , Jacques M. Holenka , Keith A. Moriarty , William R. Sloan
IPC分类号： G01V5/10
摘要： Measurement-while-drilling apparatus includes a 14 MeV neutron accelerator, a near-spaced neutron detector which primarily senses source neutrons and whose output is proportional to source strength, one or more intermediately-spaced epithermal neutron detectors eccentered against the drill collar wall and primarily responsive to formation hydrogen concentration, and a third far-spaced radiation detector, either gamma ray or neutron, primarily responsive to formation density. The intermediately-spaced and far-spaced detector outputs, normalized by the near-spaced detector output, are combined to provide measurements of porosity, density and lithology and to detect gas. A thermal neutron detector and/or a gamma ray detector may also be provided at intermediate spacings to provide additional information of interest, such as standoff measurements and spectral analysis of formation composition. Tool outputs are related to the angular or azimuthal orientation of the measurement apparatus in the borehole.
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公开(公告)号：US5051581A
公开(公告)日：1991-09-24
申请号：US517268
申请日：1990-05-01
IPC分类号： G01V5/10
CPC分类号： G01V5/108
摘要： The porosities of subsurface earth formations surrounding a borehole are investigated using a logging tool run in the wellbore by repeatedly irradiating the formations with discrete bursts of high energy neutrons, measuring the populations of epithermal neutrons at near and far locations from the neutron source, and also measuring the rate of decay of the epithermal neutron population at a third location following each neutron burst and deriving therefrom a measurement of the epithermal neutron slowing down time. Formation porosity values derived from the near-and-far location population measurements are corrected for detector standoff effects by use, in accordance with a predetermined empirical relationship, of the epithermal slow down time measurement. Alternatively, formation porosities may be derived both from the near-and-far location measurements and from the epithermal slowing down time measurement, and the two differently-derived porosity values may be used independently to provide enhanced information of formation porosity or they may be compared to derive a standoff-corrected porosity value.
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