A comparative study of inorganic alkaline/polymer flooding and organic alkaline/polymer flooding for enhanced heavy oil recovery

In this paper, interfacial tension measurements, emulsification tests, viscosity measurements, sandpack flooding tests and micromodel flooding tests were conducted for the comparative study of inorganic alkaline/polymer flooding and organic alkaline/polymer flooding for enhanced heavy oil recovery. The IFT measurement results show that NaOH, ethylenediamine and Na2CO3 all can reduce oil-water IFT to lower than 10(-1) mN/m. The addition of 0.1 wt% HPAM exerts favorable effect on the reduction of IFT between oil and alkaline solutions. Emulsification tests show that when alkaline concentration is 1.0 wt%, ethylenediamine can emulsify the heavy oil into stable 01W emulsion while 1.0 wt% NaOH emulsify the heavy oil into W10 emulsion (with a formation water containing 0.5 wt% NaCl). Viscosity measurements show that the addition of ethylenediamine can slightly increase the viscosity of polymer while the addition of NaOH and Na2CO3 can significantly reduce the viscosity of the polymer. Sandpack flooding tests show that the incremental oil recovery by ethylenediamine-HPAM flooding is higher than those by Na0H-HPAM flooding and Na2CO3-HPAM flooding. Accordingly, ethylenediamine-HPAM flooding has some advantages over inorganic alkaline/polymer flooding for enhanced heavy oil recovery. (C) 2015 Elsevier B.V. All rights reserved.