Ernie Brown & Brad Holms, Dowell Schlumberger
Carbonate formations are often stimulated by hydraulically fracturing the zone of interest with reactive fluids, most commonly hydrochloric acid. The productivity increase of the oil and gas wells where this stimulation approach is utilized, is often much less than predicted by the pretreatment design. This paper will address the problems and difficulties of properly designing an acid fracturing stimulation treatment, and will offer new techniques and alternative fluid systems that allow better designs for this type of stimulation. These new methods and fluids have recently been applied to achieve extended fracture penetration of live acid into carbonate formations, allowing higher sustained production. Results of treatments where the new designs have been utilized throughout the Permian Basin will be included as case histories.