This invention discloses a method for analyzing the mobility of original
formation water in gas reservoirs, comprising the following steps: S1, acquiring target well and target layer image data, and constructing a three-dimensional multi-pore structure model; S2, restoring the original formation conditions to the three-dimensional multi-pore structure model; S3, establishing a gas-water two-
phase displacement mathematical model based on the lattice Boltzmann method, and
coupling the two to obtain a coupled model; S4, determining the original state of the gas reservoir, setting evolutionary solution conditions, and performing evolutionary calculations on the coupled model based on the evolution equation to obtain a three-dimensional multi-pore structure model containing both gas and water phases; S5, performing multi-angle slice analysis, classifying and analyzing the mobility of the water phase, and obtaining the distribution of mobile water. This method does not require closed
coring operations and avoids subsequent high-cost experiments such as
nuclear magnetic resonance and core displacement, effectively reducing research costs, providing accurate and reliable prediction results, greatly shortening the testing and analysis cycle, and realizing the evaluation of
formation water mobility under the original conditions of gas reservoirs.