Monte Carlo simulation for determining gas saturation using three-detector pulsed neutron logging technology in tight gas reservoir and its application

A new method to accurately determine gas saturation in the tight gas reservoir using a three-detector pulsed neutron logging tool was proposed. Formation porosity is varied from 2% to 15% to simulate the distribution of thermal neutron under different borehole and formation conditions by using Monte Carlo method. The study result shows that the difference of three detectors counts can be used to determine gas saturation and have higher sensitivity than counting the ratio of different detectors.