Degradable nanocomposite preformed particle gel for chemical enhanced oil recovery applications

• A degradable nanocomposite preformed particle gel has been synthesized.
• This gel combines the processes of conformance control (gel treatment) and polymer flooding.
• An increased post-degradation gel viscosity was observed after gel degraded.

In this work, we present a preformed particle hydrogel with a more superior performance than conventional hydrogels with potential conformance control applications in mature oilfields. Preformed particle hydrogel was designed by the reaction of monomer, initiator, crosslinker, additives, and laponite XLG nanoclay, whereas conventional hydrogel is designed from just monomer, initiator, crosslinker and additives. The presence of nanomaterial in hydrogel design affords it tremendous improvement in nanocomposite gel properties and behavior compared to conventional hydrogels without any nanomaterial. On incorporation of nanomaterial, increase in gel strength of up to 394% was observed. Additionally, swelling performance, post-degraded gel viscosity, and long-term thermal resistance of nanocomposite gel increased by several orders of magnitude compared to hydrogels with no nanomaterial. Environmental Scanning Electron Microscopy (ESEM) revealed the presence of a very dense 3-D network compared to hydrogels with no nanomaterial. It was observed that after degradation, nanocomposite hydrogel had a post-degradation viscosity of 4437 cp whereas hydrogel with no nanomaterial had a post-degradation viscosity of 170 cp. Thus, degradable laponite XLG nanocomposite hydrogels are recommended for secondary polymer flooding, since they have a high post-degradation viscosity under anaerobic conditions.