Download
1 / 15
270 likes | 682 Views
Learn about CO2 Enhanced Oil Recovery (EOR) methods, advantages, reservoir screening criteria, challenges, and storage techniques. Explore CO2 utilization efficiency, transportation and operation costs, and the economic viability of CO2 injection for enhanced oil recovery and storage in reservoirs.
E N D
CO2 Enhanced Oil Recovery and Storage in Reservoirs CHE384-Energy Technology and Policy Xi Chen Nov. 19th, 2007
EOR-Background • Primary recovery • Natural pressure, 10% OOIP • Secondary recovery • Injection of water or gas, 20-40% OOIP • Tertiary or enhanced oil recovery • Aiming at recovery of 30%-60% OOIP
Categories of EOR • Thermal recovery • Steam flooding, ~50% of EOR production • Chemical injection • Polymer/water flooding, <1% • Gas injection ~50% • immiscible flooding: CH4, N2 • miscible flooding : CO2 Lecture notes from Dr. Larry W. Lake
Advantages of CO2 flooding • Dense fluid over much of the range of pressure and temperature in reservoirs • Low MMP (minimum miscibility pressure) and high miscibility with oil • Low mutual solubility with water • Low cost and abundance • Naturally occuring source • Environmental benefit if industrial CO2 is used and stored in reservoirs • Capture and sequestration of CO2 from combustion of fossil fuel
Source: Oil & Gas Journal 206,000 barrels per day in 2004 = 4% of the Nation’s total.
Screening criteria for application of CO2 miscible flood Gozalpour, “CO2 EOR and Storage in Oil Reservoirs”, 2005, Oil & Gas Science and Technology – Rev. IFP, Vol. 60 (2005), No. 3, pp. 537-546
Optimum reservoir parameters and weighting factorsfor ranking oil reservoirs suitable for CO2 EOR Rivas, O. et al. (1992) Ranking Reservoirs for Carbon Dioxide Flooding Processes.
Technical challenge • Poor sweep efficiency • Gravity override • Mobility contrast • Reservoir heterogeneity • CO2 related problem • Corrosion on facilities • Solid deposition in reservoir formation • Well spacing • Greater spacing causes sweep efficiency reduction
CO2 mobility control • Foam • mixed surfactants as foaming agent • Thickening agent • Fluorinated compound or polymer (good solubility in CO2) • Chemical gels • In-situ gelation of polymer to lower permeability
CO2 Storage in Reservoirs • Most favorable site for storage • Dense webs of seismic and well for long-term trap • Surface and subsurface infrastructure readily converted for CO2 distribution and injection • Less costly
CO2 Storage in Reservoirs • CO2 capacity of a reservoir: • Theoretically, equal to the volume previously occupied by the produced oil and water • Other factor: Water invasion, gravity segregation, reservoir heterogeneity and CO2 dissolution • Reservoir type, depth, size and safety of CO2 storage
Economics • Cost of CO2 from different sources: • Naturally occuring CO2: $14/t • Pure anthropogenic CO2 from chemical plant: $18/t • Capture and processing of CO2 from coal fired plant: $18-54/t • CO2 utilization efficiency: 4~8 Mscf/bbl (0.2~0.5t/bbl) • Transportation cost: $0.5~1.2/Mscf • Operation cost: $2-3/bbl • Economical even at a oil price of $40/bbl. • CO2 storage credit ($2.5/Mscf) makes it more economical for producers. Lako, P. (2002) Options for CO2 Sequestration and Enhanced Fuel Supply.
Summary • Combination of CO2 EOR and storage in reservoirs provides a bridge between reducing greenhouse gases from industrial waste streams and the beneficial use of CO2 injection for increasing oil and gas recovery.
