Simulation and analysis of wormhole formation in carbonate rocks considering heat transmission process

Compared with the existing two-scale continuum model, the numerical simulation results obtained with the coupled model show that both the dissolution patterns and the pore volume required to break through are affected by the temperature. The influence of the acid temperature around the wellbore on the matrix acidizing efficiency and on the optimal acid injection rate is more significant than that of the initial formation temperature. Furthermore, both the pore volume required for breakthrough and the optimal acid injection rate increase with the acid temperature, which is consistent with previous experimental results. The temperature around the wormhole is slightly higher when reaction heat is considered, and its effects on stimulation efficiency are not significant. The effects of the formation properties are analyzed by the coupled model, demonstrating that a larger volume of acid is required to break through a more homogeneous formation with higher porosity.