The well acidizing program is directly related to the efficiency of oil production. Common research that aimed at improving the efficiency of acid treatment in sandstone reservoir mainly includes the modification and adaptation of reagents to minimize formation damage that occurs due to the interaction of an acid with rock. To use new and unique acid compositions in real conditions is difficult because of organizational issues. Therefore, the traditional compositions based on a mixture of hydrochloric and hydrofluoric acids are commonly used on oilfields. The article is based on the approach of increasing the productivity of well by choosing the optimal design of treatment based on acidizing process modeling. The article describes aspects of practical implementation of the previously developed simulator of acid treatment of sandstone reservoirs, based on a numerical model of hydrodynamic and physicochemical processes in a porous medium based on unstructured PEBI-grids. The main uncertainties of the model are identified and analyzed. Here some issues that were included in current research: the density of colloidal silica formed as a result of the interaction between acid and rock, the influence of empirical parameters presented in main equations, and modeling of the mineralogical composition of the rock. The article describes an algorithm for static modeling of the near-wellbore zone for the purposes of acidizing modeling and an approach to optimize the treatment of near-wellbore zone based on the adaptation of the results of acid flow tests. The necessity of secondary and tertiary reactions modeling was approved. A number of calculations with the use of real data were carried out to determine the optimal volume of acid composition injection. Previous experience was analyzed and used for giving new recommendations to improve the acid treatment efficiency in researched and simulated conditions.
References
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