涂硼MRPC热中子探测器用于补偿中子测井的蒙特卡罗研究

Monte Carlo simulation on the application of boron-coated MRPC thermal neutron detector to the compensated neutron logging

本文利用蒙特卡罗方法模拟了涂硼多气隙电阻板室(Multi-gap Resistive Plate Chamber,MRPC)热中子探测器和3He正比计数管在常规条件和欠平衡条件下的补偿中子测井中的响应。模拟结果表明,使用涂硼MRPC热中子探测器时,得到近远探测器计数随孔隙度而增加,且与使用3He正比计数管时得到的结果基本一致,说明涂硼MRPC热中子探测器可用于补偿中子测井。

Background： The compensated neutron logging technology is widely used in oil exploration and development. The neutron detector commonly used in this technology is the helium-3 proportional counter. Due to the decreasing in supply of the helium-3 gas, the price of the helium-3 proportional counter rises quickly. Purpose： The aim is to develop a new type of neutron detector to replace the helium-3 tubes in the compensated neutron logging technology. Methods： A new thermal neutron detector coated with a layer of thermal neutron convertor in the inner glass of the Multi-gap Resistive Plate Chamber （MRPC） was developed. Under the conventional and underbalanced conditions, Monte Carlo method was used to simulate the response of the boron-coated MRPC thermal neutron detector and helium-3 proportional counter employed in compensated neutron logging technology. Results： It is shown that the SS/LS increases with the rise of porosity using either the boron-coated MRPC thermal neutron detector or the helium-3 proportional counter, and the results of these two detectors are basically identical. Conclusion： It indicates that the boron-coated MRPC thermal neutron detector can be used for compensated neutron logging.