Acid Fracturing Results for Well AZ-47D, Los Azufres Geothermal Field in Mexico

Abstract

In Mexico acid treatments, as matrix acidizing has been used to remove well damage for several years, reducing the skin factor by removing bentonite mud, silica or calcium scale, in both production and injection wells with successful results. However an matrix acidizing treatment is not designed to enhance the permeability or to create channels to communicate a low permeability well with the main naturally conduits or fractures for better fluid flow. In such a case acid fracturing technique can be successfully apply. An acid fracturing job consist in injecting fluids into the formation above the rate and natural fracture pressure, in order to open, clean and enhance flow channels with actual low permeability to obtain much better production or even to convert a marginal production well to a commercial one. In this paper, the design, execution and results of the application of an acid fracturing job in well Az-47D is presented.