公开(公告)号：US09835757B2

公开(公告)日：2017-12-05

申请号：US14396010

申请日：2012-04-23

申请人： Weijun Guo ,  Dennis Durbin ,  Kwok-Shan Kwong

发明人： Weijun Guo ,  Dennis Durbin ,  Kwok-Shan Kwong

IPC分类号： G01V5/10 ,  G01V5/04 ,  G01V5/12

CPC分类号： G01V5/045 ,  G01V5/101 ,  G01V5/125

摘要： Casing condition is an important concern to oilfield operators. Systems and methods are disclosed herein for using neutron logging tools to measure casing condition, using windows in the gamma energy spectrum that are sensitive and insensitive to casing condition to obtain a ratio having a value that ranges between one extreme representative of completely absent casing and an opposite extreme representative of casing in good condition. The sensitive (“divergence”) window may be positioned at or near 7.65 MeV, the characteristic energy of gamma rays from a neutron capture event by an iron nucleus. The insensitive (“consistency”) window is preferably adjacent to the divergence window with a comparable size to the divergence window. A suitable division point between the windows may be about 6.25 MeV.

公开(公告)号：US20150108339A1

公开(公告)日：2015-04-23

申请号：US14396010

申请日：2012-04-23

申请人： Weijun Guo ,  Dennis Durbin ,  Kwok-Shan Kwong

发明人： Weijun Guo ,  Dennis Durbin ,  Kwok-Shan Kwong

IPC分类号： G01V5/04 ,  G01V5/10

CPC分类号： G01V5/045 ,  G01V5/101 ,  G01V5/125

摘要： Casing condition is an important concern to oilfield operators. Systems and methods are disclosed herein for using neutron logging tools to measure casing condition, using windows in the gamma energy spectrum that are sensitive and insensitive to casing condition to obtain a ratio having a value that ranges between one extreme representative of completely absent casing and an opposite extreme representative of casing in good condition. The sensitive (“divergence”) window may be positioned at or near 7.65 MeV, the characteristic energy of gamma rays from a neutron capture event by an iron nucleus. The insensitive (“consistency”) window is preferably adjacent to the divergence window with a comparable size to the divergence window. A suitable division point between the windows may be about 6.25 MeV.

摘要翻译： 套管条件是油田经营者的重要担忧。 本文公开了使用中子测井工具来测量套管状况的系统和方法，其使用对能量谱敏感且对壳体条件不敏感的伽马能谱中的窗口，以获得具有范围在完全不存在壳体的一个极端值与 对面极端代表套管状况良好。 敏感（“发散”）窗口可以位于或接近7.65MeV，即来自中子捕获事件的γ射线的特征能量。 不敏感（“一致性”）窗口优选地与发散窗口相邻，具有与发散窗口相当的大小。 窗户之间的合适的分割点可以是大约6.25MeV。