Use closed reservoirs for CO2 storage and heat recovery: A two-stage brine-extraction and CO2-circulation strategy

Mingjie Chen*, Ali Al-Maktoumi, Azizallah Izady, Jianchao Cai, Yanhui Dong

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Integrated CO2 (carbon dioxide) geologic storage (CGS) and CO2 plume geothermal (CPG) production provides an attractive approach not only to reduce atmospheric CO2 concentration but also to generate carbon-free geothermal energy to supplement electricity power. The current CGS-CPG studies are mostly limited to large-scale thick saline formations with open boundaries. Small to moderate scale closed-boundary reservoirs, which are typical for oil/gas fields, have rarely been evaluated for CGS-CPG. One of the major reasons is that the closed system has limited storage volume, and native brine has nowhere to escape to free storage space for injected CO2. This study provides a solution to this issue by implementing an innovative two-stage operational strategy to realize CGS-CPG in closed reservoirs. The proposed strategy extracts pure hot brine and CO2 in two sequential stages by two separate wells, and can effectively avoid brine-CO2 separation on ground surface. A suite of numerical models is developed to evaluate the approach with a variety of reservoir conditions and operations. Results demonstrate the feasibility of our solution for implementing CGS-CPG in closed systems, and indicate the tremendous potentials to use depleted oi/gas reservoirs as the candidate fields, which widely exist in North Oman and the world.

Original languageEnglish
Article number102346
JournalSustainable Energy Technologies and Assessments
Volume52
DOIs
Publication statusPublished - Aug 2022

Keywords

  • Brine extraction
  • Closed system
  • CO circulation
  • Fault-blocked reservoirs
  • Geothermal energy harvest

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology

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