Validating Surfactant Performance in the Eagle Ford Shale: A Correlation between the Reservoir-on-a-Chip Approach and Enhanced Well Productivity

For liquids-rich shale plays, surfactants have proven to be a critical component in hydraulic fracturing fluid systems for enabling enhanced oil and gas recovery. The industry's most commonly used surfactant is a non-emulsifying surfactant (NES), but it has been previously demonstrated that a weakly emulsifying surfactant (WES) appears to be more efficient at mobilizing oil through tight pore throats. In this study, fundamental differences between those two surfactant types were further demonstrated using a Reservoir-on-a-Chip (ROC) approach, which allows direct visualization of oil recovery with the various surfactant fluids, allowing for the testing on both homogenous and heterogeneous pore structures with various geometries. The laboratory testing showed that, compared to a non-surfactant-bearing control fluid and the NES, the WES showed higher oil recovery efficiency at equal driving pressure.

As a result of the laboratory testing indications, a multiple well trial program was conducted in two separate areas of the Eagle Ford shale. Production data from the wells stimulated using a WES-bearing fracturing fluid were normalized in terms of lateral lengths and fracturing stages, and compared to the offset wells stimulated using a NES-bearing fracturing fluid. Early production results suggest that wells treated with the WES exhibited enhanced productivity compared to those treated with the NES.