EOR Agent Screening on a Chip
Compare chemical, gas and thermal enhanced oil recovery methods on a visualized reservoir model before costly core flooding.
| EOR classes | chemical, gas, thermal, foam |
|---|---|
| Conditions | up to 89 MPa and 350 °C |
| Agents | surfactants, polymers, alkali, CO₂, N₂, hydrocarbon gases, APG, steam, foams |
| Micromodels | homogeneous and heterogeneous, digital core replicas, fractured, layered |
| Measurements | pressure and differential, temperature, flow, pore volumes, breakthrough time |
| Metrics | displacement efficiency, incremental recovery, residual oil saturation, front stability |
| Optics | transmitted and fluorescent light, phase segmentation, saturation maps |
| Deliverables | agent ranking, report, video, recommendations for core and pilot |
EOR selection means testing dozens of formulations, concentrations and injection schemes, and moving the whole matrix to core makes the program expensive. Bottle tests and interfacial tension measurements do not show how an agent spreads in the pore space, while emulsification, adsorption, early gas breakthrough or foam collapse only appear under flow.
A single screening program is built for the field conditions: fluid composition, micromodel geometry, wettability, temperature, pressure, flow rate and injection sequence. The chip is saturated with formation water and oil, a reference water or gas flood is run, and then surfactants, polymers, surfactant–polymer formulations, gases (including huff-n-puff and WAG), foams, steam and combined schemes are tested under one protocol.
Image, pressure, temperature, flow rate and injected volume are recorded synchronously. Agents are ranked by incremental recovery, front stability, pressure drop, fluid compatibility and absence of adverse effects, and the video shows mobilization of trapped oil, emulsion or foam formation and gas breakthrough. The micromodel can reproduce the porosity, permeability, fractures, layering and wettability of a specific reservoir.
Only the best formulations and regimes move on to the core program. For example, in one surfactant program 4 of 12 formulations were selected as the most effective for core testing.