In 2010, exploration of gas-rich and possible liquid-rich shale reservoirs began in northern Mexico. The initial challenges as in any exploration project were to demonstrate the availability of reserves and set the foundation for future development of plays. Wells were aimed at the upper cretaceous Eagle Ford formation and at the Jurassic Pimienta formation. While exploration campaign continues, the first development wells have been drilled in some areas. A total of 19 horizontal wells have been drilled and completed by January 2014.

The wells drilled in the latest stage of the exploration campaign in the Pimienta formation presented additional complexity, which led to an undesired trend of increased costs and extended completion times. Also, some of the wells drilled and completed during an earlier stage of the exploration campaign showed a rapid decline in production which directly threatened future development plans. To reverse these trends, a novel dynamic diversion technology for hydraulic fracturing treatments was implemented with positive results. This technology improves distribution of hydraulic fracturing treatments along the horizontal section of the wells, therefore allowing the stimulation of longer perforated intervals at once, ensuring that a great majority of the perforated clusters are efficiently stimulated. The need for mechanical plugs, to isolate the different hydraulic fracturing stages in the wells; the risk associated with pump down of plugs and milling times to remove these plugs were greatly reduced, which results in improved completion times and costs.

This study presents four case histories in which the technology was applied. One of the cases refers to re-fracturing operations of the last 3 stages in a well with a horizontal section of approximately 1,500m which was initially stimulated with 17 hydraulic fracturing stages. The remaining cases refer to the completion of three exploratory wells in which the horizontal section was stimulated with multiple hydraulic fracturing stages using the dynamic diversion technology. The treatments were evaluated using different techniques which mainly included: radioactive tracers and pressure response analysis. Initial results showed evidence of diversion both in pressure response and tracer log analysis, as well as stable production after stimulation. Interpretation of radioactive tracer logs and numerical production forecasting results confirm effectiveness of methodology applied.

The application of this technology can lead to a significant improvement in the efficiency of completions and effectiveness of stimulations of unconventional reservoirs in Mexico and around the world.