Environmental Impact of Bitumen Extraction with Thermal Recovery

Abstract

Abstract The continuous and growing demand for energy and carbon based products requires the extraction of massive bitumen resources. Due to extremely high viscosities of bitumen, the most effective bitumen extraction methods are thermal enhanced oil recovery (EOR) methods such as In-situ Combustion (ISC), Steam Assisted Gravity Drainage (SAGD), Steam Flooding (SF), and Hot Water Injection (HWI) which are known as environmentally unfriendly bitumen extraction methods. In this study, we investigated the environmental impact of in-situ bitumen extraction by ISC, SAGD, SF, and HWI, experimentally. The original oil, water, and rock, produced oil and water, and spent rock samples originated from each recovery method were analyzed through Fourier Transform Infra-Red (FTIR) spectroscopy, Inductive Coupled Plasma – Mass Spectroscopy (ICP-MS), pH, viscosity, and API gravity measurements. The environmental impact was investigated according to the amount and content of produced water and gas samples and the quality of oil to reduce the impact during bitumen refining. The experimental results showed that while with ISC, the least amount of water is produced; the produced water requires more severe treatment due to its high metal and sulfur contents, and low pH level. On the other hand, since the amount of the produced water for SAGD, SF, and HWI is higher, the produced water management poses handling problems. The oil production from ISC results in the greatest recovery with upgraded oil which will reduce the environmental impact for oil processing when compare to SAGD, HWI, and SF. While all processes produced more or less the same amount of gases, SAGD and SF have additional gas production due to steam generation. As conventional resources decline, it is essential to address environmental challenges to produce from these massive oil sand resources. In this study, the environmental impacts of bitumen extraction with thermal EOR were examined extensively.