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公开(公告)号：US5128541A
公开(公告)日：1992-07-07
申请号：US104750
申请日：1987-10-05
IPC分类号： G01V5/10
摘要： A borehole logging method for determining thermal neutron decay characteristics of a formation surrounding the borehole, comprises the following steps. The formation surrounding the borehole is irradiated from a location within the borehole with a burst of neutrons and indications of the concentration of the diffusing thermal neutrons are detected in at least three time gates following the burst of neutrons. Corresponding count rate signals in response to the detected neutrons are produced. Thereafter, the count rate signals are combined in a predetermined manner to separate a characteristic of the thermal neutron decay rate of the formation from associated neutron diffusion characteristics which are monotonically decreasing with time. The steps of irradiating, detecting and combining are then repeated at different depth locations within the borehole and a recording of the rate of decay of thermal neutrons as a function of borehole depth is produced.
摘要翻译： 用于确定围绕钻孔的地层的热中子衰变特性的井眼测井方法包括以下步骤。 围绕钻孔的地层由钻孔爆发的中子从钻孔内的位置被照射，并且在中子爆发之后的至少三个时间门中检测到扩散热中子的浓度的指示。 产生响应于检测到的中子的相应的计数率信号。 此后，以预定的方式组合计数速率信号，以将由形成的热中子衰减速率的特性与随时间单调递减的相关联的中子扩散特性相分离。 然后在钻孔内的不同深度位置重复照射，检测和组合的步骤，并且记录热中子衰减速率作为钻孔深度的函数。
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公开(公告)号：US20080028453A1
公开(公告)日：2008-01-31
申请号：US11731011
申请日：2007-03-29
申请人： Thinh Nguyen , Shaun Cuttill , Timothy Nguyen , Mehrzad Mahdavi
发明人： Thinh Nguyen , Shaun Cuttill , Timothy Nguyen , Mehrzad Mahdavi
IPC分类号： H04L9/32
CPC分类号： H04L63/0815 , G06F21/335 , H04L63/102
摘要： A method for authenticating a user involves receiving a request from the user to access a resource, where the resource is associated with at least one authentication requirement, determining a trust level associated with access to the resource, obtaining user credentials based on the trust level associated with the resource, selecting an authentication method for authenticating the user based on the trust level associated with the resource, generating user authentication information based on the trust level associated with the resource and the user credentials obtained, where user authentication information relates to the user's environment while accessing the resource, sending the user authentication information to the resource, and granting access to the resource, if the user authentication information meets the at least one authentication requirement of the resource.
摘要翻译： 用于认证用户的方法涉及从用户接收访问资源的请求，其中资源与至少一个认证要求相关联，确定与对资源的访问相关联的信任级别，基于相关信任级别获得用户凭证 利用资源，选择用于基于与资源相关联的信任级别来认证用户的认证方法，基于与资源相关联的信任级别和获得的用户证书生成用户认证信息，其中用户认证信息涉及用户环境 如果所述用户认证信息满足所述资源的所述至少一个认证要求，则在访问所述资源时向所述资源发送所述用户认证信息，并授予所述资源的访问权限。
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公开(公告)号：US5523556A
公开(公告)日：1996-06-04
申请号：US248811
申请日：1994-05-24
申请人： Steve Meddaugh , Mehrzad Mahdavi , Stefan Vajda
发明人： Steve Meddaugh , Mehrzad Mahdavi , Stefan Vajda
摘要： A Cockcroft-Walton (CW) multiplying circuit is mounted to wrap around a cylindrical structure. A photomultiplier tube (PMT) has a photocathode which emits electrons and has dynodes connected to the CW multiplying circuit. The dynodes are biased to attract electrons from the photocathode. An electrical shield surrounds the PMT and the PMT nests within the shield. The cylindrical structure surrounds the shield and the shield nests within the cylindrical structure. The shield is a conductive material which electrically isolates the PMT from the CW multiplying circuit.
摘要翻译： 安装了Cockcroft-Walton（CW）乘法电路以围绕圆柱形结构。 光电倍增管（PMT）具有发射电子并具有与倍频电路连接的倍增电极的光电阴极。 倍增极被偏置以从光电阴极吸引电子。 电屏蔽围绕PMT和PMT嵌套在屏蔽内。 圆柱形结构围绕屏蔽并且屏蔽件嵌套在圆柱形结构内。 屏蔽是将PMT与CW乘法电路电隔离的导电材料。
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公开(公告)号：US5235185A
公开(公告)日：1993-08-10
申请号：US819541
申请日：1992-01-09
申请人： Paul Albats , Russell C. Hertzog , Mehrzad Mahdavi
发明人： Paul Albats , Russell C. Hertzog , Mehrzad Mahdavi
IPC分类号： G01V5/10
CPC分类号： G01V5/105
摘要： A tool which contains a pulsed accelerator neutron source and means for making timing measurements of the thermal neutron response in a localized portion of the environment immediately surrounding the borehole. Formation sigma is determined by parameterizing the detected thermal neutron decay curve, preferably with a diffusion model similar to that known in the art for determining formation sigma on the basis of gamma ray time distributions. In a more comprehensive embodiment of the present invention, which includes a gamma detector in the tool, formation sigma can be measured in parallel using both gamma ray and thermal neutron decay characteristics. Deviations between the neutron and gamma-based signals that occur as the tool traverses the borehole, provide useful indications of local effects immediately surrounding the borehole.
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公开(公告)号：US4947040A
公开(公告)日：1990-08-07
申请号：US455807
申请日：1989-12-20
IPC分类号： G01V5/10
摘要： A borehole logging method for determining the porosity of a formation surrounding the borehole, comprising the steps of: irradiating the formation surrounding the borehole from a location within the borehole with a burst of neutrons, detecting at a near detector indications of the concentration of thermal neutrons following the burst of neutrons and generating near count rate signals as a function of time in response thereto, detecting at a far detector indications of the concentration of thermal neutrons following the burst of neutrons and generating far count rate signals as a function of time in response thereto, fitting a count rate model to the near count rate signals to determine a near impulse formation count rate amplitude, fitting a count rate model to said far count rate signals to determine a far impulse formation count rate amplitude, determining the ratio of the near and far count rate signals as a characteristic proportional to the porosity of the formation.
摘要翻译： 一种用于确定围绕钻孔的地层的孔隙度的钻孔测井方法，包括以下步骤：用钻井中子从井眼内的位置照射钻孔周围的地层，在近处检测到热中子浓度的指示 在中子脉冲之后并产生近似计数速率信号作为响应于时间的函数，在远检测器处检测指示中子脉冲之后的热中子的浓度，并产生作为响应时间的函数的远计数率信号 将计数速率模型拟合到近计数率信号以确定近似脉冲形成计数速率幅度，将计数速率模型拟合到所述远计数速率信号以确定远冲激形成计数速率幅度，确定近似 和远计数率信号作为与地层孔隙度成比例的特征。
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