Using Carbon Dioxide to Enhance Recovery of Methane from Gas Hydrate Reservoirs: Final Summary Report

• Main Authors: McGrail, B. Peter, Schaef, Herbert T., White, Mark D., Zhu, Tao, Kulkarni, Abhijeet S., Hunter, Robert B., Patil, Shirish L., Owen, Antionette T., Martin, P F.
• Other Authors: United States. Department of Energy.
• Format: Report
• Language: English
• Published: Pacific Northwest National Laboratory (U.S.) 2007
• Subjects: Natural Gas; Hydrocarbons; 02 Petroleum; Sand; Microemulsions; Enhanced Recovery; Bearings; Hydrates; Petroleum; Methane; Carbon Dioxide; Multiphase Flow; Gas Hydrates; Mixtures; 03 Natural Gas; Stability; Methan Gas Hydrate; Carbon Dioxide Sequestration; Thermodynamic Properties; Transport Methan Gas Hydrate; Market; Alaska North Slope; Methane hydrate; north slope; Alaska
• Online Access: https://doi.org/10.2172/929209; http://digital.library.unt.edu/ark:/67531/metadc902700/

Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Use of CO2 for enhanced recovery of oil, conventional natural gas, and coal-bed methane are in various stages of common practice. In this report, we discuss a new technique utilizing CO2 for enhanced recovery of an unconventional but potentially very important source of natural gas, gas hydrate. We have focused our attention on the Alaska North Slope where approximately 640 Tcf of natural gas reserves in the form of gas hydrate have been identified. Alaska is also unique in that potential future CO2 sources are nearby, and petroleum infrastructure exists or is being planned that could bring the produced gas to market or for use locally. The EGHR (Enhanced Gas Hydrate Recovery) concept takes advantage of the physical and thermodynamic properties of mixtures in the H2O-CO2 system combined with controlled multiphase flow, heat, and mass transport processes in hydrate-bearing porous media. A chemical-free method is used to deliver a LCO2-Lw microemulsion into the gas hydrate bearing porous medium. The microemulsion is injected at a temperature higher than the stability point of methane hydrate, which upon contacting the methane hydrate decomposes its crystalline lattice and releases the enclathrated gas. Small scale column experiments show injection of the emulsion into a CH4 hydrate rich sand results in the release of CH4 gas and the formation of CO2 hydrate