EOR Performance and Modeling

In spite of continued investment and advances in exploiting alternative energy sources, oil and natural gas will continue to be a significant portion of US and global energy portfolios for decades. Enhanced oil recovery (EOR) uses unconventional hydrocarbon-recovery methods that target the approximately two-thirds of the oil volume remaining in reservoirs after conventional-recovery methods have been exhausted. Though limited by high capital and operating costs, EOR techniques will have a substantial effect on the future supply of oil.

In 2011, SPE hosted an EOR conference in Kuala Lumpur, and three workshops to address EOR technologies in Malaysia, Kuwait, and the Syrian Arab Republic. The Malaysia workshop focused on chemical-EOR methods, the Kuwait workshop addressed opportunities and for challenges of EOR methods in the Middle East, and the Syrian Arab Republic workshop discussed EOR in carbonate reservoirs. More than 300 EOR papers were published in SPE conferences, with many additional presentations in EOR workshops. These papers address important issues related to practical application of conventional EOR methods and the development of novel EOR technologies. The topics cover experience with, opportunities for, and challenges of EOR technologies; fundamental study of EOR mechanisms for different methods; feasibility study and improvement of an EOR method for a specific reservoir; EOR-screening criteria; reservoir surveillance, monitoring, and evaluation technologies; reservoir simulation and modeling; lessons learned from EOR pilot and field trials; and some novel EOR methods.

Polymer flooding has been proved the most cost-effective chemical-EOR method in the laboratory and in the field. A recent focus on polymer flooding evaluated associative polymers because of their advantage over traditional hydrolyzed polyacrylamide (HPAM) polymers; thus, one paper about comparing the flow behavior of associative polymer and HPAM in porous media was selected for this feature.

CO2 injection is a win/win strategy because it can enhance oil recovery and be used for CO2 storage in reservoirs to reduce greenhouse-gas levels in the atmosphere. However, CO2 EOR targets maximum oil recovery while CO2 sequestration targets maximum storage capacity without leakage. One paper featured here provides some guidance to balance the two technologies.

Steamflooding has been applied successfully in heavy-oil reservoirs. However, one paper synopsized in this feature will describe successful steamflooding in a lightoil reservoir.

EOR opportunities in the Middle East are also highlighted.

Read the paper synopses in the January 2012 issue of JPT.

Baojun Bai, SPE, is an associate professor of petroleum engineering at Missouri University of Science and Technology. Previously, he was a reservoir engineer and head of a conformance-control team for PetroChina. Bai holds PhD degrees in petroleum engineering and in petroleum geology. He serves on the JPT Editorial Committee and as a technical editor for SPE Journal and SPE Reservoir Evaluation & Engineering.

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