Jujo Teco is one of the most important oil fields located in southern Mexico. It produces an average oil gravity of 35 API, which is combined with the heavy oil from offshore Mexico to enrich the Mexican oil blend. Sustaining oil production rates is one of the main targets for this mature field, and controlling the water produced is one of the primary challenges to keep the oil production up to the desired levels. Performing conformance treatments in this field is also a major challenge. Formations to be treated are naturally fractured carbonates averaging depths of 19,000 ft with bottomhole temperatures above 300°F. They are completed in openhole sections with typically 300 ft of exposed formation. It is especially difficult to address if the water-control treatments are bullheaded because there is no way to distribute and place the fluids in the right zone without the risk of sealing off the oil producing sections.
Using coiled tubing for placing these types of treatments has been a viable alternative to increase the rate of success on these deep, openhole completions in conjunction with the introduction of a high-temperature conformance polymer. The cases presented in this paper show how the water cut has remained almost zero in some instances, even when the treatment was performed three years ago.