TY - JOUR
T1 - CO2 enhanced oil recovery and storage using a gravity-enhanced process
AU - Li, Liwei
AU - Khorsandi, Saeid
AU - Johns, Russell T.
AU - Dilmore, Robert M.
N1 - Funding Information:
This project was funded in part by the Department of Energy, National Energy Technology Laboratory , an agency of the United States Government, through a support contract with URS Energy & Construction, Inc. Neither the United States Government nor any agency thereof, nor any of their employees, nor URS Energy & Construction, Inc., nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/11/1
Y1 - 2015/11/1
N2 - CO2 flooding offers a means to recover significant amounts of oil while simultaneously sequestering CO2. Recent methods for CO2 geological storage have focused on CO2 injection into deep brine aquifers, or by water-alternating-gas (WAG) injection in a miscible gas flooding process using vertical wells. There is significant uncertainty in the amount of CO2 that can be stored using these methods owing to reservoir heterogeneity and variations in reservoir/fluid parameters. It would be useful therefore to have a more robust process that can also increase both CO2 storage and oil recovery in a symbiotic relationship, where increased storage leads to greater oil recovery.This paper considers an alternative process that maximizes both storage and oil recovery simultaneously using only horizontal wells in a gravity-enhanced miscible process. A reduced-order model (ROM) is developed to consider a wide range of reservoir heterogeneities and fluid properties. Monte-Carlo simulations using the ROM show that achieving very high storage and oil recovery is possible using the gravity-enhanced process and that the approach is very robust. For example, after 2.0 moveable pore volumes injected (MPVI), probabilistic forecasts show that CO2 storage efficiency across two standard deviations ranges from about 81% to 93%, indicating that nearly all of the available pore space (excluding immobile water) at the end of injection is occupied by CO2. Oil recoveries after 2.0 MPVI varied from 79% to 93% of the original mass of oil-in-place (OOIP). These storage and recovery efficiencies are significantly greater than any process reported to date. Response functions developed can also be used to estimate the maximum amount of stored CO2 and corresponding oil recoveries for a wide range of reservoir and fluid properties. Such estimates are critical for regional and national assessment of CO2 storage potential.
AB - CO2 flooding offers a means to recover significant amounts of oil while simultaneously sequestering CO2. Recent methods for CO2 geological storage have focused on CO2 injection into deep brine aquifers, or by water-alternating-gas (WAG) injection in a miscible gas flooding process using vertical wells. There is significant uncertainty in the amount of CO2 that can be stored using these methods owing to reservoir heterogeneity and variations in reservoir/fluid parameters. It would be useful therefore to have a more robust process that can also increase both CO2 storage and oil recovery in a symbiotic relationship, where increased storage leads to greater oil recovery.This paper considers an alternative process that maximizes both storage and oil recovery simultaneously using only horizontal wells in a gravity-enhanced miscible process. A reduced-order model (ROM) is developed to consider a wide range of reservoir heterogeneities and fluid properties. Monte-Carlo simulations using the ROM show that achieving very high storage and oil recovery is possible using the gravity-enhanced process and that the approach is very robust. For example, after 2.0 moveable pore volumes injected (MPVI), probabilistic forecasts show that CO2 storage efficiency across two standard deviations ranges from about 81% to 93%, indicating that nearly all of the available pore space (excluding immobile water) at the end of injection is occupied by CO2. Oil recoveries after 2.0 MPVI varied from 79% to 93% of the original mass of oil-in-place (OOIP). These storage and recovery efficiencies are significantly greater than any process reported to date. Response functions developed can also be used to estimate the maximum amount of stored CO2 and corresponding oil recoveries for a wide range of reservoir and fluid properties. Such estimates are critical for regional and national assessment of CO2 storage potential.
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U2 - 10.1016/j.ijggc.2015.09.006
DO - 10.1016/j.ijggc.2015.09.006
M3 - Article
AN - SCOPUS:84942312580
VL - 42
SP - 502
EP - 515
JO - International Journal of Greenhouse Gas Control
JF - International Journal of Greenhouse Gas Control
SN - 1750-5836
ER -