In this paper, the compensated neutron logging is transformed into the Thermal Neutron Cross Section Logging (TNXS) to improve the application effect. Because the compensated neutron logging measures the neutron count, TNXS cannot be directly measured by the compensated neutron logging tool. Moreover, the thermal neutron ratio cannot be directly converted into the TNXS due to the influence of lithology and fluid. The ratio of thermal neutron count is related not only to the formation hydrogen index, but also to the formation density and the formation capture cross section. The density and the capture cross section of formations can be used to reduce the influence of lithology and fluid. Therefore, the thermal neutron counting ratio can be converted into the TNXS by density and the capture cross section of formations. The accuracy of the porosity calculated by the TNXS is studied based on the Monte Carlo method. The results show that the thermal neutron counting ratio can be accurately converted to the TNXS by density and the capture cross section of formations. The porosity calculated by TNXS is closer to the formation porosity than that calculated by the compensated neutron logging, especially in gas-bearing formations and complex lithologic formations.

本文将补偿中子测井转换为热中子截面测井（TNXS），以提高应用效果。由于补偿中子测井法测量中子数，因此无法通过补偿中子测井仪直接测量TNXS。此外，由于岩性和流体的影响，热中子比不能直接转换为TNXS。热中子数的比率不仅与地层氢指数有关，而且与地层密度和地层捕获截面有关。地层的密度和捕获横截面可用于减少岩性和流体的影响。因此，可以通过密度和地层的捕获截面将热中子计数比转换为TNXS。基于蒙特卡罗方法研究了TNXS计算出的孔隙度的准确性。结果表明，通过密度和地层俘获截面可以将热中子计数比准确地转换为TNXS。TNXS计算的孔隙度比补偿中子测井计算的孔隙度更接近地层孔隙度，尤其是在含气地层和复杂岩性地层中。