Surveillance and optimization: critical to CO_2 flooding: Operators must make an ongoing effort to manage CO_2 performance

摘要

Knowledge about how to optimize a CO_2 EOR project has grown dramatically in recent years as the number of active CO_2 EOR floods worldwide has more than doubled, from 65 in the mid-'90s to more than 145 today. During this same time period, U.S. projects have increased from 55 to 130. CO_2 EOR's growing popularity is due in large measure to its efficiency at "cleaning" oil from the rock. But since the properties of CO_2 in the reservoir are such that overall "sweep" through the reservoir will likely be lower than during a waterflood, it is important to know that the CO_2 is doing its job, contacting oil and moving it. And now that supplies of CO_2 are constrained, the cost of CO_2 for EOR projects is higher, and surveillance is even more important. Therefore, active reservoir management and ongoing pattern management is critical. This can only be achieved through an active, ongoing surveillance and optimization effort. Without such an effort, a CO_2 flood's performance can easily and quickly spiral out of control, and its profitability can suffer.