Int. J. of Oil, Gas and Coal Technology   »   2016 Vol.11, No.2

 

 

Title: Thermo-EOR effect during steam injection in carbonate heavy oil reservoirs

 

Authors: Junwoo Seo; Wonmo Sung

 

Addresses:
Department of Natural Resources and Environmental Engineering, Hanyang University, Seoul, 133791, Korea
Department of Natural Resources and Environmental Engineering, Hanyang University, Seoul, 133791, Korea

 

Abstract: When the thermal method is applied to carbonate rock, the imbibitional flow into tight matrix can be increased by thermally induced wettability alteration. Furthermore, CO2 is generated by geochemical reaction between steam and carbonate rock, resulting in thermo-EOR, which is similar to CO2 flooding. In this study, we developed geochemical model to predict the generation of CO2 and implemented this model into a thermal simulator. Using this thermal model, we investigated thermo-EOR effect by the generated CO2 in heavy oil carbonate reservoirs and analysed the capillary imbibition resulting from the wettability alteration. From the results, we determined that thermo-EOR effect from the generated CO2 only occurred under the influence of immiscible flow, which yielded additional 12.5% of oil recovery. This gain was obtained from additional decrease in oil viscosity by the dissolved CO2 in oil and further increase in pore pressure due to the volume of the CO2 gas. [Received: September 10, 2014; Accepted: January 19, 2015]

 

Keywords: carbonate reservoirs; steam injection; wettability alteration; capillary imbibition; in-situ CO2; carbon dioxide; carbon generation; thermo-EOR effect; enhanced oil recovery; heavy oil reservoirs; imbibitional flow; geochemical modelling; simulation; immiscible flow; oil viscosity; pore pressure.

 

DOI: 10.1504/IJOGCT.2016.074288

 

Int. J. of Oil, Gas and Coal Technology, 2016 Vol.11, No.2, pp.111 - 126

 

Available online: 21 Jan 2016

 

 

Editors Full text accessAccess for SubscribersPurchase this articleComment on this article