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Simulation Study of CO2 EOR and Storage Potential of the Commercial-Scale Integrated CCUS Demonstration Project in the Ordos Basin, China


Normal 0 false false false EN-US ZH-CN X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0in; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} The objective of the study is to develop a commercial scale integrated CCUS project which include CO2 enhanced oil recovery (CO2 EOR), enhanced water recovery (CO2 EWR) and geological storage. To achieve this goal, the team has taken the Yanchang tight sandstone reservoir in the Ordos Basin, China as a case study to characterize the target reservoir in three dimensions, to match the reservoir production performance history and to optimize enhanced oil recovery using various CO2injection and production scenarios. , and to investigate CO2 storage potentials during and in completion of the production. First, Object-based litho-facies modeling was used to integrate well-log facies, sandstone dimension, channel sinuosity and orientation in building the 3-D facies model. The facies model was then used to guide petrophysical property modeling. Compositional simulation model was built by integrating realistic static model, fluid model, hydro-fracture model, rock physical model and fluid production history matching. Laboratory fluid analysis results, including oil composition, saturation pressure, density, differential liberation test were tuned to an equation of state. In addition, to simulate miscible CO2 injection process, swelling test and minimum miscible pressure (from slim tube test) were also matched. Relative permeability curves were obtained through history matching with 15 production wells and 5 water injection wells. The CO2 enhanced oil recovery strategy is based on 5 water injection well. Various CO2 injection schemes including continuous CO2 injection, water alternating gas injection (WAG), and soaking. For different injection schemes, several scenarios were carried out to investigate the sensitivity of injection parameters, like injection rate, WAG ratio, soaking time etc.. The continuous CO2 flooding gives auspicious results (highest oil recovery), while soaking scenario showed higher storage efficiency. Simulation results also indicate that reservoir heterogeneity and hydro-fracture limit the potentials of CO2 EOR and storage due to fast CO2 breakthrough and less sweep efficiency in tight sandstone reservoirs.