Foam as a Diverting Technique for Matrix Sandstone Stimulation

Abstract

Abstract It is often difficult to adequately treat the entire perforated interval in a damaged, gravel packed well. Foam was evaluated in the laboratory as a diverting technique for hydrofluoric acid treatments, and encouraging results led to field evaluation of foam diverting in 12 wells in the Gulf of Mexico. Generation of stable foam at low pump rates was aided by the use of a coil tubing unit, which further enhances treatment results by enabling the various fluids to be spotted at or below the perforated interval. Two different techniques were used in these treatments: staged foam injection and foam injection during the first third of the treatment. Production data was used to evaluate the foam diverting technique. Also, temperature logs were run before and after one treatment to provide further information on the benefits of foam. Advantages and disadvantages of foam diverting as well as treatment design procedures, laboratory data, and production data relating to foam diverting in matrix hydrofluoric acid treatments are presented in this paper.