FOAMS: Improving Production in Mature Wells. SPE-209399-MS: Energy and Environmental Efficiency / Energy efficiency (E.E.) / Energy efficiency (C.I)

The evaluation of energy and environmental efficiencies has been incorporated as part of the screening criteria of EOR projects in Colombia. The CSS + foam pilot program was the first project incorporating energy efficiency (E.E.) and carbon intensity (C.I) indexes as criteria for evaluating technologies at pilot and potential commercial scale in MMV assets. The E.E. represents an energy balance referenced in terms of BTU (British Thermal Units). This index is the ratio between the energy required to generate steam and foam (i.e., NG, water, and N2 pumps) and the energy produced during the steam cycle (i.e., barrels of oil) and was first documented by Osma et al. (2019).

The E.E. was developed using a numerical modeling approach and was incorporated in the CSS + foam pilot. In summary, for E.E < 1, the process is considered energy efficient. In other words, when the energy (oil) produced is larger than the energy required during the CSS + foam cycle, the process will be considered efficient. A similar approach was used to estimate the C.I. index, which represents the ratio of the total mass (kg) of CO2 emitted during the CSS + foam injection with respect to the incremental oil recovered (CO2 equivalent), considering that the solution gas of the produced oil is negligible.

The extension of the CSS production cycles due to the injection of preformed foams represents more oil produced with the same amount of NG burned for steam generation. The avoided NG burned improved carbon footprint and MBTU required to produce a barrel of oil.