Experimental Study of the Change in Porosity of Imeri Oilsand Rock Contaminated with CO2

Abstract

This research studies the effect of CO₂ on Imeri oilsand located in Ogun East, Nigeria. The experiment is to investigate the possibility of using the oilsand as a possible CO₂ storage reservoir and also to investigate the possible effect of CO₂ leakage from nearby stored reservoir on the oilsand reservoir. It was observed that there was gradual increase in porosity of the oilsand core up to 7.89% in the first 16days after intermittent injection of CO₂. After this maximum change in porosity there was a sudden gradual decrease in the measured porosity. The oilsand core outer surface was observed to have become hardened, with an increase of 30.94% in the fracture pressure, after 30 days of initial CO₂ injection and after exposure to air forming and the formation of a seal-like material at the exposed outer surface. This is suspected to be due to reaction of this oilsand with the injected CO₂ resulting into formation of cementing material or a type of CO₂ hydrates. The material formed is been investigated in the second part of this research as it may be a very good sealing material which could provide clue to the storage ability of oilsand as a CO₂ storage.

Keywords: Oilsand, CO₂ contamination, CSS, crude viscosity, Imeri oilsand, Nigeria oilsand