Acidizing process in acid fracturing

Abstract

The theory and numerical implementation of acid-fracturing model that solves the 2D fracture geometry leakoff, acid transport and acid-rock reaction simultaneously will be presented. The mathematical model proovides a penetration distance for acid fracturing. Due to limitation of analytical solution, a finite-difference method was developed for modelling the fracture acidizing process. Example was solved for HCl reaction in limestone and dolomite fractures, and the results are presented in graphical form. The acid-transport model integrates a number of features which were not accounted for an earlier design models: comprehensive study of hydrodynamic process; acidizing controlled by mass transfer, rate of reaction, and leakoff. Coupling with reservoir forecasting models gives the ability to optimize the job.