Greenhouse gas (GHG) emissions related to the Farnsworth Unit’s (FWU) carbon dioxide enhanced oil recovery (CO2-EOR) operations were accounted for through a gate-to-gate life cycle assessment (LCA) for a period of about 10 years, since start of injection to 2020, and predictions of 18 additional years of the CO2-EOR operation were made. The CO2 source for the FWU project has been 100% anthropogenically derived from the exhaust of an ethanol plant and a fertilizer plant. A cumulative amount of 5.25 × 106 tonnes of oil has been recovered through the injection of 1.64 × 106 tonnes of purchased CO2, of which 92% was stored during the 10-year period. An LCA analysis conducted on the various unit emissions of the FWU process yielded a net negative (positive storage) of 1.31 × 106 tonnes of CO2 equivalent, representing 79% of purchased CO2. An optimized 18-year forecasted analysis estimated 86% storage of the forecasted 3.21 × 106 tonnes of purchased CO2 with an equivalent 2.90 × 106 tonnes of crude oil produced by 2038. Major contributors to emissions were flaring/venting and energy usage for equipment. Improvements on the energy efficiency of equipment would reduce emissions further but this could be challenging. Improvement of injection capacity and elimination of venting/flaring or fugitive gas are methods more likely to be utilized for reducing net emissions and are the cases used for the optimized scenario in this work. This LCA illustrated the potential for the CO2-EOR operations in the FWU to store more CO2 with minimal emissions.

The focal point of this project is to investigate and assess the potentiality of an enhanced waterflooding process by a naturally generated surfactant (Protein-Enzyme bio-surfactant). The effect of low salinity (LSW), and LSW combined with a bio-surfactant (Protein-Enzyme) in a tertiary mode flooding comparatively. A high salinity water (HS) (0.75 M) was used to flood in the secondary mode after aging the crude saturated core with an initial water saturation of 19%, a recovery of 68.15% oil initially in place (OIIP) was recovered until no further recovery. Upon flooding with a LSW (90% dilution of HS), a further incremental recovery of 11.1% OIIP was produced. Enhancing the LSW with bio-surfactant in a third flooding sequence, an additional 3.75% OIIP was recovered. Analysing the mechanism of LSW bio-surfactant with fractional flow, a high recovery of 0.583 PV (pore volumes) at breakthrough was estimated. Thus, an alteration in ionic strength (salinity) by a 90% dilution and combination of bio-surfactant, saw an incremental recovery, which indicates the potential of LSW bio-surfactant on recovery of residual oil saturation.

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The properties of Protein enzyme biosurfactant, a green-enzyme, water-based inert-enzyme generated from the DNA of microbes that eat oil was studied to ascertain its applicability in EOR processes. A light crude oil of 0.908 g/cc at 22°C density and 53.87 cp viscosity was used in this study with a kinematic viscosity which was variable between 90.654 mm2/s to 13.7544 mm2/s between temperatures of 22.5 °C to 70 °C with a measured surface tension of about 35 mN/m. The bio-surfactant yielded a CMC value of 0.02 wt.% which is comparable to reported CMC values of other surfactants. The least IFT value measured was 4.0 mN/m, which is very high for a very efficient and effective residual oil recovery (an ultralow IFT of about 0.01mN/m is required of which was achievable by Rhamnolipid a bio-surfactant studied alongside Protein Enzyme in this work). Ionic (0.083M to 3.0M) and temperature (23 to 70 °C) effects did not have much influence on the activities of bio-surfactant, thus quite stable within such conditions. The protein-enzyme has the ability to form a Winsor type III emulsion and stable over the period of time studied. Adsorption was noticed especially with higher bio-surfactant concentrations but tends to be stable over time.