Preformed Particle Gels (PPG) Improve Oil Recovery in Mature Oil Fields

Long term water flooding induces high permeability channels, potentially increasing the water cut and increased water production becomes the most prominent challenge faced in mature oil fields. Preformed particle gels (PPGs) are larger in size than other commercially available blocking/plugging agents and preferentially penetrate in to high permeability zones, leaving the low permeability zones undamaged. This helps maximize oil recovery during water flooding, allowing the injected water to sweep the earlier unswept low permeability zones. We designed two parallel tubes of same dimensions and packed each of them with sand packs such that they represent low permeability and high permeability layers of a reservoir without cross flow (non-cross flow heterogeneity). The purpose of the experiment was to examine PPGs preferential injection in to high permeability zones and the effective increase in oil recovery during water flooding from the low permeability and high permeability zones after PPG placement. Results indicated that PPGs effectively block the high permeability zones, allowing water to sweep the low permeability zones and recover the trapped oil