K. Sandengen, K. Melhuus and A. Kristoffersen
Event name: IOR 2017 - 19th European Symposium on Improved Oil Recovery
Session: Polymer II
Publication date: 24 April 2017
Info: Extended abstract, PDF ( 1.53Mb )
Price: € 20
There exist several mentions of HPAM polymers leading to reduced end point saturation; commonly referred to as “viscoelastic effect”. Huh and Pope(2008) proposed that polymers act as to maintain oil phase continuity, meaning that an impact can only be induced before oil breaks up into discontinuous ganglia. Hence, if their proposed mechanism is correct, common tertiary mode investigations would be misleading and cannot capture the full potential effect. The present work was therefore initiated with the aim of testing the hypothesis of Huh and Pope. A reservoir rate core flood study was performed in a “micro-CT” imaging system enabling pore scale (≈ 7 µm) resolution of fluids. Tertiary polymer injection, did not change oil saturation, which was in agreement with the hypothesis. Thereafter oil was injected into the porous medium, which already contained polymer, to increase oil saturation. Subsequent polymer injection led to higher SOR, which was in complete contradiction to the hypothesized lowering of SOR. The results reported herein, did consequently not fit with the expectations from the hypothesis at question. On a general basis the results do therefore not support claims that polymer flooding, due to the viscoelastic nature of the fluid, should lead to a lower SOR.