A systematic multi-scale experimental investigation of a newly developed halloysite nanotubes reinforced preformed particle gel for improving oil recovery from heterogeneous reservoir: Synthesis, characterization, optimization and performance assessment

Abstract

Preformed particle gel (PPG), a recent gel treatment technique, is being utilized in reducing excessive water production to reduce its environmental impact and to improve the oil recovery in matured oilfields. In this research article a new class of PPG called Halloysite Nanotubes Reinforced Preformed Particle Gel (HNR-PPG) has been developed using acrylamide (monomer); n, n′- methylenebis (acrylamide) (crosslinker); halloysite nanotubes (reinforcement agent) and potassium persulphate (initiator) for water shut-off jobs. The results from chemical and morphological characterization viz. Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), Powder X-ray diffraction (PXRD), Field Emission Scanning Electron Microscopy (FESEM), and Energy dispersive X-ray spectroscopy (EDS) analyses suggest a successful synthesis of HNR-PPG. Swelling kinetics studies of HNR-PPG illustrate a faster rate of swelling in early phases and a relatively slow rate in later stages with an optimum swelling ratio of 24.56 (g/g). Rheological studies have demonstrated that reinforcement of halloysite nanotubes has increased its strength from 4611 Pa [i.e., for ‘PPG without reinforcement’ or ‘Conventional PPG’ (C-PPG)] to 6251 Pa [i.e., for ‘HNR-PPG’]. Thermogravimetric analysis (TGA) outcomes have deduced that the degradation temperature of the backbone of the main crosslinked chain has increased from 361 °C to 382 °C due to reinforcement, thus improving its thermal resistance. Single sandpack experiments elucidate good plugging ability in terms of permeability reduction (65–81%). To simulate a heterogenous non-cross flow reservoir, parallel sandpack experiments were conducted and the profile improvement rate is found to be around 81%, 87% and 90% for the permeability contrast of 2.25, 3.11 and 3.41 respectively after the HNR-PPG injection. Thus, the newly developed HNR-PPG can potentially improve water shut-off jobs and oil recovery in mature oil fields.