Monte Carlo simulation to key parameters of a compensated neutron logger

Monte Carlo simulation to key parameters of a compensated neutron logger 1 2 first-author 1 2 corresp Corresponding author. E-mail address: bjyang9@163.com Corresponding author. E-mail address: bjyang9@163.com bjyang9@163.com 1 2 1 2 2 Provincial Key Lab of Applied Nuclear Techniques in Geosciences, Chengdu University of Technology, Chengdu 610059, China Provincial Key Lab of Applied Nuclear Techniques in Geosciences, Chengdu University of Technology, Chengdu 610059, China Chengdu University of Technology, Chengdu 610059, China Chengdu University of Technology, Chengdu 610059, China A compensated neutron logger (CNL) is designed by using Monte-Carlo simulation for lead shield thickness, near-to-far detector spacing range, source-to-detector spacing range, and detector's effective length. The calculated results indicate that the optimum conditions for CNL are 80-mm thick lead plus 1-cm thick LiOH shield in front of the near detector, 250 mm for the near-to-far detector distance ( Δr) , and the source-to-detector distance ( r ) of 90mm. Simultaneously, some conclusion also obtained here, near/far detector counting response ratio ( R ) increases with the effective length of detector, R increases with the porosity for oil and water sandstones, and the oil sandstone is a bit greater than water sandstone. Monte Carlo MCNP Logging CNL optimal design References Ding D Z , Ye C T , Zhao Z X . Neutron physics: principles, methods and applications . Beijing : Atomic Energy Press , 2001 , 951 - 961 (in Chinese) . Neutron physics: principles, methods and applications Tuo X G , Mu K L , Lei J R , et al . Nucl Tech , 2007 , 30 : 388 - 390 (in Chinese) . Nucl Tech Hearsta J R . Nucl Instrum Methods , 1974 , 117 : 141 - 151 . Nucl Instrum Methods Serov I V , John T M , Hoogenboom J E . Appl Radiat Isot , 1998 , 49 : 1737 - 1744 . Appl Radiat Isot Zhang J M , Xia L Z , Qiu Y X , et al . At Energy Sci Technol , 2006 , 40 : 125 - 128 (in Chinese) . At Energy Sci Technol Xia L Z , Zhang J M , Yang Z G , et al . Well Logging Technol , 2003 , 27 : 477 - 480 (in Chinese) . Well Logging Technol Pang J F . Nuclear logging physics basis . Beijing : Petroleum Industry Press , 2005 , 127 - 128 (in Chinese) . Nuclear logging physics basis Qiu Y X , Xia L Z , Peng H , et al . Well Logging Technol , 2004 , 28 : 471 - 477 (in Chinese) . Well Logging Technol Briesmeister J F . MCNPTM-A general monte carlo N-Particle transport Code (4C) , Los Alamos, New Mexico : Los Alamos National Laboratory , 2000 . MCNPTM-A general monte carlo N-Particle transport Code (4C) 10.13538/j.1001-8042/nst.20.359-362 Partially supported by National Key Technology R&D Program of China (2008BAK47B04) , Innovation Method Work (2008IM040500) , National Natural Science Foundation of China (40673058) and Sichuan province Key Technology R&D Program (2008GZ0040, 2008GZ0197) 2009-04-27 2009-12-20 2021-01-19 2009 Nuclear Science and Techniques 06 20