Experimental Evaluation of Minimum Miscibility Pressure for CO2 Miscible Flooding at Farnsworth Field, Texas and Burbank Field, Oklahoma

摘要

CO2 miscible flooding is currently the most common of all the enhanced oil recovery (EOR) methods. In addition to the improved oil recovery potential it is also looked at as an option to contribute to reducing greenhouse gas emissions by the industry. Ability of CO2 to develop miscibility with oil is an important factor making the technique effective. The knowledge of miscibility is established in terms of the minimum miscibility pressure (MMP). It is a key parameter in designing a successful CO2 flooding project.;The objective of this research is to evaluate the experimental MMP for two fields namely Burbank field in Osage County, Oklahoma and Farnsworth field in Ochiltree County, Texas using slim tube method. In the case of Burbank field, tests were conducted for four oil samples from different parts of the field using CO2. Similarly, for the Farnsworth field oil sample tests were conducted for both pure CO2 and impure CO2 injection gas streams. Methane is the most prominent impurity, so tests were conducted using reservoir fluid with CO2 gas contaminated with methane.;MMP for different samples from Burbank field was estimated experimentally using slim tube tests with injection gas as CO2. The results obtained will be further utilized in reservoir simulation models. The miscibility tests for Farnsworth field using pure CO2 were conducted and the MMP was evaluated. The miscibility tests used an injection gas (blended in lab) to replicate the impure CO2 mixture (containing a total methane impurity of 10 mol percent). This resulted in a MMP nearly 6.5 percent higher than that found using the >99% pure CO2 gas. These results can be utilized to further modify and optimize the CO2 flooding operation design.;Funding for this project is provided by the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) through the Southwest Regional Partnership on Carbon Sequestration (SWP) under Award No. DE-FC26-05NT42591.