Alkaline-Surfactant-Polymer Flood Application for Enhanced Oil Recovery Has Potential for Significant Recovery of Remaining Reserves in the Mature Lawrence Field, Illinois

Within the Illinois Basin, most of the oilfields are mature and have been extensively water-flooded with water cuts that range up to 99% in many of the larger fields. In order to maximize production of significant remaining mobile oil from these fields, new recovery techniques need to be researched and applied. The Illinois State Geological Survey has been working with the Department of Energy to conduct research on multiple types of Enhanced Oil Recovery (EOR) projects. A project using alkaline-surfactant-polymer (ASP) has been established in the century old Lawrence Field in southeastern Illinois where original oil in place (OOIP) is estimated at over a billion barrels and 400 million barrels have been recovered leaving more than 600 million barrels as an EOR target. Radial coreflood analysis using core from the field demonstrated recoveries greater than 20% of OOIP. While the lab results are likely optimistic to actual field performance, the ASP tests indicate that substantial reserves could be recovered even if the field results are 5 to 10% of OOIP.

Reservoir characterization is a key factor in the success of any EOR application. Reservoirs within the Illinois Basin are frequently characterized as being highly compartmentalized resulting in multiple flow unit configurations. The research being conducted on Lawrence Field focuses on characteristics that defined reservoir compartmentalization in order to delineate preferred target areas so that the chemical flood can be designed and implemented for the greatest recovery potential. Along with traditional facies mapping, core analyses and petrographic analyses, conceptual geological models were constructed and used to develop 3D geocellular models, a valuable tool for visualizing reservoir architecture and also a prerequisite for reservoir simulation modeling.

An overview of this body of research will be presented. Chemical flooding is being initiated in stages with the first flood initiated in 2010 and a second offset initiated during 2011. The data results from these floods will be presented as it becomes available.
 

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California