Simulation and analysis of matrix stimulation by diverting acid system considering temperature field

An experimental evaluation of novel VES diverting acid shows that the growth of a secondary wormhole is longer and the dissolution morphology is more uniform than that of the main wormhole. During the process of diversion, there is an obvious protrusion in the pressure drop curve of the acid. The simulation and analysis results show the following: The simulation of acid entering into multiple layers shows that diverting the acid can effectively increase the amount of acid entering into the low permeability layer, which results in a better development of a wormhole in a low permeability layer. It also reduces the non-uniformity of the acid distribution between the layers. The effects of the bottomhole temperature on the diverting acid viscosity exceed the effect of the reaction rate and the diffusion coefficient, which results in a higher bottomhole temperature, and worse diversion effect. The injection displacement of acid has a slight effect on the diverting effect. The higher the displacement, the better the effect of diversion. The heterogeneity of a formation has a significant effect on the diverting effect, namely, the higher the heterogeneity, the weaker the effect.