Do you expect your stimulation surfactant to deliver greater well performance? You should. So, why are surfactants typically only optimized to prevent water-oil emulsions? Preventing emulsions only reduces potential formation damage; it does not increase oil recovery from your well.
Often, the only surfactant test being performed at the field level is a basic demulsification test. Although this test demonstrates the surfactant’s ability to prevent a water-oil emulsion, it does not always indicate why a surfactant should be used. In fact, this test sometimes shows that no surfactant at all is needed. In reality, however, the right surfactant can increase your load recovery and, more importantly, increase your well productivity.
To determine the correct surfactant and loadings to be used in your stimulation fluid, several tests should be carried out. The difference between running no surfactant vs. an optimized surfactant in oil recovery tests can be dramatic and the recommended tests outlined below will reveal the value of surfactants, especially with regard to enhanced post frac oil recovery.
- Interfacial Tension Reduction (IFT) between the oil and stimulation fluid.
- Column Drainage – tests the flow of stimulation fluid and oil through a column packed with shale cuttings and sand.
- Amott Cell Spontaneous Imbibition – stimulation fluid imbibition/oil displacement and recovery testing.
The more tests that can be performed, the more confidence you will have in your surfactant selection!