Table 2.
Decision table highlighting the different aspects of ME formulation in the laboratory for technical assessment in conformance improvement.
| Stepwise Methodology | ME Formulation Techniques | Outcomes | Strategy/Decision |
|---|---|---|---|
| Surfactant screening & analysis | Cost analysis | Low cost of procurement | Proceed |
| Very high costs involved | Abort | ||
| Market Accessibility | Readily prepared or available | Proceed | |
| Not available, or incur high transportation costs | Alternative | ||
| HLB and micellization | Ideal HLB in the 8–12 range, low CMC | Proceed | |
| Unfavorable HLB but low CMC | Proceed | ||
| Very high CMC, leading to high rock retention tendency | Alternative | ||
| ME Phase behavior analysis | ME synthesis route | Employ suitable method in lab | Proceed |
| Ternary phase diagram | Identify favorable 2+ phase systems in the presence of low surfactant conc. | Proceed | |
| Identify favorable compositions, but with high surfactant requirement | Alternative | ||
| Phase visualization | Winsor I, II, III types with low coalescence rate | Proceed | |
| Phase separation occurs quickly (few mins-hrs) | Abort | ||
| Characterization | Dynamic light scattering | ME droplets measured in nanometric range | Observe, Analyze |
| Effect of salinity on droplet size | |||
| Microscopy | Droplet morphology and size | Observe, Analyze | |
| Solubilization studies | Optimal solubilization and IFT behavior | Observe, Analyze | |
| Relative tendency to solubilize water/oil | |||
| Salinity scan | Phase transition among different Winsor types | Observe, Analyze | |
| Relative Phase volume curves with salinity | |||
| Physicochemical evaluation | Viscosity | Pseudoplastic flow character with moderate to high viscosity under shear | Proceed |
| Pseudoplastic behavior with very low viscosity | Alternative | ||
| Dilatent flow behavior | Abort | ||
| Stability | Viscosity and/or zeta potential remains nearly constant with elapse of time | Proceed | |
| Fluctuating trends in viscosity/zeta potential with time | Alternative | ||
| Economic factor | Cost analysis | Functional with low/manageable operating costs | Proceed |
| Scope for incurring significant costs during setup, maintenance and operation | Abort | ||
| Environmental concern | Degradability | ME components are degradable or can be retracted | Proceed |
| Leads to rock retention and formation damage | Abort | ||
| Toxic in nature, and potency to spread to nature | Abort | ||
| Reservoir needs | Porous media flow studies | ME shows favorable behavior in desired rock systems | Proceed |
| Undesirable features and rock-fluid incompatibility | Abort |
Decision columns for each outcome are marked in different colors as shown. Green = Proceed with the strategy; Yellow = Search for alternative approach; Red = Abort the formulation process; Blue = Observe and analyze the result only.