Evaluation of enhanced oil recovery from clay-rich sandstone formations

In the last few years, there has been a growing interest in smart water (SW) flooding as economically and environmentally friendly method to Enhanced Oil Recovery (EOR) in sandstone and carbonated reservoirs. Formation damage especially fines migration and clay swelling by lowering salinity and changing the ionic environment, causes the significant decrease in permeability of the sandstone reservoirs. In this study, an experimental study has been undertaken to illuminate the effect of formation damage during smart water injection as the function of clay types. The state of the art procedure has been established in direction of sandpack construction containing favorable clay content. Injection of smart water was performed in sandpacks with different clay types (montmorillonite and kaolinite). The results show that the presence of montmorillonite augments formation damage and enhances oil recovery. Analyzing Interfacial Tension (IFT) experimental data showed that interaction of oil/SW had no great influence on increasing oil recovery. The results have been achieved based on extensive experiments including Differential Pressure (DP) measurements, Zeta potential, and Recovery Factor (RF). Two mechanisms were proposed to interpret permeability reduction and amount of oil produced values which are clay swelling, and detachment/re-attachment for montmorillonite and kaolinite, respectively.Armin Bazyari, Mohammad Jamialahmadi, Bahram Soltani Soulgani and Abbas Zeinijahrom

Introduction of a novel mathematical model for the prediction of the preformed particle gel’s swelling in the presence of monovalent and divalent ions

Abstract Excess water production is one of the challenges that can cause several operational and economic problems. In this work, a comprehensive study of the PPG swelling in the presence of monovalent and divalent ions was conducted. Then, a comprehensive and practical mathematical modified fractal grow (MFG) model that can calculate the amount of PPG swelling in different salinities overtime was introduced. The output of the model was compared with the experimental data and showed a matching of about 80%. The viscosity of the PPGs at various shear rates was studied and matched with the cross-viscosity model. To assess the thermal stability of the particle gels. The TGA result represented the 10% of weight loss up to the reservoir temperature. In the following, core flooding tests with different injection scenarios were conducted. The oil recovery for the water and water/PPG/water scenarios were 39.5% and 71.5%, respectively. Eventually, the relative permeability curves were plotted using the Corey approach, and the effect of the PPG injection on the relative permeability curves was shown. The PPG injection increased oil production and reduced the excess water production by reducing water mobility