CSS: Strategies to Recovery Optimization

Abstract

This paper was written with the main propose to share the experience of more than ten years of cyclic steam stimulation (CSS) in a heavy oil field with a big amount of challenges such as low injectivity, sanding, steam channeling, low steam efficiency, among others. For each item identified with a high impact on the CSS production and efficiency, a methodology to analyses and optimization was developed. the first step is identifying the item, recollect the information and quantify the impact; after that, the information is analyzed by the reservoir team, some solution is suggested and evaluated by numerical simulation and other tools; then, the best solution found is apply like a pilot on the field and according to the results it is implemented in a full field scale or replanting until to get the hope results. Finally, corrective actions are taken to avoid similar troubles in the future development of the field. Lesson learners are divulged to the members of the organization. For the case of low injectivity, this was identifying in the first stage of development of the field; we carried on lab cores to found the presence of swelling shales like the main causes. Inhibitors clays were test on lab and implemented in the first cycles; for the next steps of development we acquired steam generators with a high-pressure setting too. On the other hand, steam channeling was identified in wells with more of five cycles of stimulation; others wells with potential channeling was identified too, and a methodology to inject this kind of wells was development with the help of simulation tools and successfully implemented in field. The injection of other fluids with the steam like nitrogen, foam or gels improved the low steam efficiency; the development methodology is included in the paper. This papers include a lot of experiences in the improving of cyclic steam stimulation, test lab, numerical simulation and other tools are combined with the field experience obtaining an improve in the oil production. Real data field, CSS information and developed methodologies are included in the paper. For this reason, this paper is useful to future implementation of CSS process and in other fields with similar features.