Session: 11-08-01 Advances in Carbon Capture Utilization and Storage (CCUS)

Paper Number: 128132

128132 - Modeling Thermal-Hydrological-Mechanical (Thm) Processes for Co2 Sequestration in Depleted Gas Reservoirs 

Over the past two decades, researchers have devoted enormous efforts into developing numerical models for simulating CO₂ geo-sequestrations. Due to the large temporal and spatial scales associated with such processes, numerical modeling has proven to be the most effective and cost-effective to evaluate them. Presently, the majority of the existing models were developed for CO₂ sequestration in saline aquifers. In contrast, the number of models for depleted gas reservoirs is relatively small, and only a fraction of them have the capability to consider geomechanical and thermal coupling or complicated natural gas compositions.

CO₂ sequestration in depleted gas reservoirs is considered a promising technique for combating global warming. The use of depleted gas reservoirs has several advantages over saline aquifers, such as the availability of existing facilities and the proven capacity and stability of gas storage. It is believed that CO₂ storage in depleted petroleum reservoirs can provide intermediate-scale storage until large-scale storage in saline aquifers becomes mature.

 Here we propose an Equation of State (EOS) module for CO₂ sequestration in depleted gas reservoirs or CO₂-enhanced gas recovery. It takes into consideration the mutual solubilities in the CO₂-hydrocarbon gas-brine system based on the equality of the chemical potentials of the aqueous and non-aqueous phases. In such a way, it can properly address CO₂ dissolution into brine when hydrocarbon gas is present. Hydrocarbon gas includes methane, ethane, and propane. It employs well-recognized approaches to calculate the thermodynamic properties of the gaseous and aqueous phases. This EOS module has been applied to our in-house simulator, TOUGH2-CSM, to enable thermal-hydrological-mechanical modeling. Our research could fill the gap and provide a reference for future studies in this regard.

Presenting Author: Yu-Shu Wu Colorado School of Mines

Presenting Author Biography: Bio: Dr. Yu-Shu Wu is a professor in petroleum reservoir engineering and director of Energy Modeling Group (EMG) research center in the Petroleum Engineering Department at the Colorado School of Mines (CSM), USA. He is a fellow of the Geological Society of America (GSA). He held MS and PhD degrees in reservoir engineering from University of California at Berkeley, and B.S. (Eqv.)/MS degrees in petroleum engineering from Northeast and Southwest Petroleum Universities in China. He has been a Guest Scientist at the Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA, since 2008, participating in collaborated research projects on development on unconventional natural gas resources, nuclear waste disposal, CO2 sequestration, CCUS, enhanced or engineered geothermal systems (EGS), and cryogenic fracturing technology.
At CSM, he teaches and carries out research in reservoir engineering, multiphase fluid and heat flow, geomechanics, unconventional oil and gas reservoir dynamics, CO2 EOR and geosequestration, and geothermal reservoir engineering. He leads the EMG in its research effort in (1) flow and simulation of conventional and unconventional oil and gas reservoirs; (2) coupled processes of multiphase fluid and heat flow, geomechanics, and chemical reaction in porous and fractured rock; (3) Gas/CO2 EOR and sequestration; (4) improved formation stimulation/cryogenic fracturing technologies; and (5) hydraulic fracturing modeling. Previously, he was a staff scientist with the Earth Sciences Division of LBNL for 14 years (1995–2008). During his career, he has authored and coauthored more than 160+ peer-reviewed journal papers, 2 books, and 21 peer-reviewed book chapters as well as 84 SPE papers.

Authors:

Xinrui Zhao Colorado Schoolof Mines
Philip Winterfeld Colorado School of Mines
Yu-Shu Wu Colorado School of Mines