Numerical Investigations on the Transport Properties of Thermal Neutron in Saturated Porous Media with Digital Rock

Summary In this research, the digital rock has been constructed with the pileup of the segmented images of X-ray CT data from the carbonate samples. The transport of thermal neutrons has been simulated with the Monte Carlo method to reveal the correlation between the counts difference of neutrons and porosity, to investigate the effects of water saturation. Instead of a detector used in the conventional researches, the 8x8 array detectors are utilized to detect the transmitted neutrons, which can help to investigate and image the anisotropy of pore structure. Based on the simulated results, it is observed that the calculation of porosity with the neutron data can be affected by the anisotropy of pore structure and the saturation. The significance of fluids content in the porosity evaluation can synchronously increase with the increasing of water saturation. Moreover, a new mathematical model has been proposed to relate the counts difference to the porosity and saturation, which can actually be taken as a new method to calculate the saturation with the porosity and the counts difference of neutrons.