The article discusses results of core flooding studies to determine optimal filtration modes of acid compositions in cores from different producing fields, as well as comparison of mathematical models matched with the laboratory studies results to be applied in the software engineering tools for carbonate acidizing design. Various approaches to the mathematical description of wormholes formation in core samples have been considered and, finally, it was decided upon semiempirical models as best-suited for complex engineering tool for carbonate acidizing design. For model matching, a series of core flooding experiments were performed. Different initial concentrations of hydrochloric acid, and different additives to control reaction rate were used. A good match between the models and the forecast data was obtained. To extrapolate these models to field conditions, two universal models based on two different approaches, a simplified pseudostationary single-phase isothermal model and a non-stationary multi-phase non-isothermal model, were developed, which were integrated with the semiempirical models. It was found that the non-stationary multi-phase non-isothermal model has a greater potential for forecast of matrix acidizing performance, however the simplified pseudostationary single-phase model can be useful as a proxy-model to perform quick calculations. The results demonstrate that the models can be successfully realized in the acidizing design software tools. The developed models were the basis of the software package for modeling and design of carbonate acidizing in fields operated by PJSC TATNEFT.
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