Mechanisms of Nanofluid Based Modification MoS2 Nanosheet for Enhanced Oil Recovery
Recently, much attention has been directed towards the applications of nanofluids for enhanced oil recovery (EOR). Here, amphiphilic molybdenum disulfide (KH550-MoS2) nanosheets were synthesized using a hydrothermal approach. The physicochemical properties and potential EOR of ultra-low concentration KH550-MoS2 nanofluids were systematically investigated under reservoir conditions at Changqing Oilfield (China) (temperature~55℃ and salinity~7.8×104 mg/L). Interfacial tension (IFT), wettability change, and emulsion stability were measured to evaluate the physicochemical properties of the KH550-MoS2 nanofluids. The results showed that ultra-low concentration of KH550-MoS2 nanofluid (50 mg/L) could decrease IFT to 2.6 mN/m, change the contact angle (CTA) from 131.2° to 51.7° and significantly enhance emulsion stability. Core flooding experiments were conducted to determine the dynamic adsorption loss law and the oil displacement efficiency of KH550-MoS2 nanofluid. The results indicated that the ratio of cumulative produced KH550-MoS2 nanosheets to the total injected KH550-MoS2 nanosheets (CNR) reached 91.5% during flooding in low permeability reservoirs. Moreover, ultra-low concentration KH550-MoS2 nanofluid can increase the oil displacement efficiency by 14% after water driven. This study shows the physicochemical properties of the KH550-MoS2 amphiphilic nanofluid and offers a novel high- efficiency amphiphilic nanofluid for EOR