Downhole Heavy Crude Oil Upgrading Using CAPRI: Effect of Steam upon Upgrading and Coke Formation

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• 作者：Abarasi Hart ; Gary Leeke ; Malcolm Greaves ; Joseph Wood
• 刊名：Energy & Fuels
• 出版年：2014
• 出版时间：March 20, 2014
• 年：2014
• 卷：28
• 期：3
• 页码：1811-1819
• 全文大小：334K
• 年卷期：v.28,no.3(March 20, 2014)
• ISSN：1520-5029

文摘

Heavy crude oil and bitumen are characterized by a low yield of light distillates in the range of 10鈥?0% with a boiling point below 350 掳C, high density (low API gravity), high viscosity, and high heteroatom content, which impede their exploitation. In this study, the catalytic upgrading process in situ (developed by the Petroleum Recovery Institute, Canada) add-on to the toe-to-heel air injection for the extraction and upgrading of heavy oil and bitumen downhole was investigated. The effect of steam addition and steam-to-oil ratio upon upgrading, coke formation, sulfur and metal removal were examined using a Co鈥揗o/纬Al₂O₃ catalyst at a reaction temperature of 425 掳C, pressure of 20 bar, gas-to-oil ratio of 500 mL路mL^鈥?, and steam-to-oil ratio in the range of 0.02鈥?.1 mL路mL^鈥?. It was observed that the coke content of the spent catalyst reduced from 17.02 to 11.3 wt % as the steam-to-oil ratio increased from 0.02 to 0.1 mL路mL^鈥? compared to 27.53 wt % obtained with only nitrogen atmosphere after 15 h time-on-stream. Over the same range of conditions, 88鈥?2% viscosity reduction was obtained as steam-to-oil ratio increased compared to 85.5% in nitrogen atmosphere only, a substantial reduction from the value of 1.091 Pa路s for the feed oil. It was also found that although desulfurization increased from 3.4% in a steam-free atmosphere to 16鈥?5.6% over the increasing range of steam flows investigated, demetallization increased from 16.8% in a steam-free environment to 43鈥?0.5% depending on the increasing steam-to-oil ratio.