Paper: Acid Etching And Reaction Rate Evaluation Improve Stimulation Results

Stimulation of carbonates with acid has been and will continue to be one of the most economical means of improving the performance of both production wells and injection wells. Performance improvement is accomplished through the proper match-up of fluids and techniques to the reservoir The beginning of a successful stimulation starts with an understanding of the reservoir composition and pore system. Having defined these reservoir properties, an evaluation of fluids which will not only achieve the best differential etching in the carbonate but will also maintain rock integrity to withstand closure of conductivity pathways created by acidization comes next. Lastly, control of leak-off and reactivity for placement to insure deepest penetration and conductivity is considered. Presented are examples of implementation of the above evaluations, which have resulted in successful stimulations. These case histories cover a wide range of reservoir conditions and geographical areas.