Data Analysis and Updated Screening Criteria for Polymer Flooding Based on Oilfield Data

Enhanced-oil-recovery (EOR) screening is considered the first step in evaluating potential EOR techniques for candidate reservoirs. Therefore, as new technologies are developed, it is important to update the screening criteria. Many of the screening criteria regarding polymer flooding that have been described in the literature were based on data collected from EOR surveys of the Oil and Gas Journal. However, the data quality has not been addressed in previous research. The data set originally contained 481 polymer-flooding projects from around the world, and it contained some problems, including outliers and duplicate, inconsistent, and missing data. To ensure the quality of the data set before running analyses, boxplots and crossplots were used to detect and identify data problems. After detecting outliers and deleting duplicate and severely inconsistent data records, only 250 projects remained. Both graphical and statistical methods were used to analyze and describe the results of the data set. Two major sets of information were given after data cleaning: The first was that the majority distribution of each parameter was shown by use of a histogram distribution, and the second was that the range of each parameter and some of its statistical values were presented by use of a boxplot. Finally, the screening criteria are presented on the basis of these statistics and the defined data parameters. The developed criteria were compared with previously published criteria, and their differences were explained. The developed criteria show that a polymer-flooding project can be successfully applied in a reservoir with a temperature of less than 210 degrees F, an oil viscosity up to 5,000 cp, and gravity lower to 12 degrees API.