Paper: Methanol in Fracturing Fluid Enhances Southeastern New Mexico Stimulations

A study of stimulation techniques in the Morrow and Atoka formations was conducted because operators wanted to find a way to slow the anomalous decline in production from wells that were drilled and completed during the late 1970s and early 1980s. Operators investigated completion practices used during this period and conducted pressure-transient analysis. They analyzed sidewall cores for mineralogy studies of the reservoir rock and sensitivity testing of water and acids. From this study, we concluded that the completion fluids used were damaging the reservoir rock. Buildup analysis showed that most fracture treatments only reduced the positive skin present and rarely resulted in stimulation. This study revealed the need for a nondamaging fracturing fluid that would improve the success of fracture stimulation in the Morrow and Atoka formations. A foamed methanol system was developed to address the high clay content and water sensitivity of these formations. The paper presents the rheological, fluid-loss, and friction properties of the fluid system. Since the introduction of this system, more than 100 successful treatments have been pumped with favorable results. Case histories of both low-pressure and high-pressure zone completions are presented.