Saturday, August 02, 2014

Enhanced Oil Recovery Using Carbon Dioxide

In the 2014 Annual Energy Outlook (AEO2014), EIA projects that the price of oil will largely determine whether to use carbon dioxide (CO2) enhanced oil recovery (EOR) technologies to extract additional crude oil from existing producing fields. The injection of CO2 gas into oil reservoirs at high pressure forces the CO2 to mix with oil. This reduces the oil's viscosity and causes the oil to increase in volume (swell). The result is an increase in the total cumulative volume of oil produced and in the percentage of oil-in-place that is recovered. The decision by a producer whether or not to employ this technique depends on a number of factors, including the geophysical properties of the reservoir, the oil within that reservoir, the cost of applying CO2 EOR, and the revenue received from additional production.

graph of crude oil produced from carbon dioxide injection in AEO2014, as explained in the article text
Source: U.S. Energy Information Administration, Annual Energy Outlook 2014

The injection of miscible (capable of being mixed) CO2 into old oil fields to recover more of the oil-in-place is an expensive undertaking. The cost of the CO2 itself can add $20 to $30 per barrel of oil produced. In addition, the producer must pay for surface facilities to separate the CO2 from the production stream and compress it back into the oil reservoir. The producer also incurs a financial cost for the time delay associated with repressurizing old reservoirs. Oil prices thus play an important role in determining whether the additional production resulting from applying CO2 EOR to old fields is sufficient to make this process commercially and economically feasible. (DOE-EIA)

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