Investigation and Characterization of a Robust Nanocomposite Preformed Particle Gel for Enhanced Oil Recovery

A robust starch grafting nanocomposite-preformed particle gel (SN-PPG) with superior viscoelasticity and thermal stability is developed to improve the oil recovery. The effects of crosslinker, initiator, starch, sodium montmorillonite (Na-MMT) and thereof additives were systematically studied. Through introducing starch and Na-MMT, the storage modulus of swollen gel was ameliorated from 570 to 1420 Pa. At 80 ℃, the SN-PPG exhibited thermally stable after aging 90 d, meanwhile showed an inflection temperature of 187.3℃ in the Differential Scanning Calorimetry (DSC) measurements, which indicated an excellent thermostability. Moreover, the SN-PPG displayed a reinforced pH and salinity tolerance compared with the conventional PPG. In core-flooding tests, the SN-PPG successfully blocked the fracture aperture and improved the oil recovery by 29.86-38.59 %. Furthermore, the characterizations involving Fourier Transform-Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) confirmed the decoration ...