2019 AAPG Annual Convention and Exhibition:

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Time-Dependent Supercritical-CO2 Relative Permeability and its Impact on Large-scale CO2 Storage in Carbonate Reservoirs

Abstract

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; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} In geologic CO2 storage, supercritical (sc)CO2 -brine relative permeability may be influenced by scCO2 -brine-rock reactions. This alteration of relative permeability can significantly impact multi-phase flow properties of scCO2 displacing brine in large-scale injection of CO2 into the deep saline aquifers. We present unsteady-state core-scale CO2 drainage experiment designed to collect water production and pressure responses. We also measured endpoint CO2 relative permeability properties at in-situ reservoir brine composition, pressure and temperature conditions before and after 400 hrs aging with scCO2 saturated carbonic acid. Residual water saturation and scCO2 permeability after CO2 aging were changed from 0.62/0.03 mD to 0.68/0.04 mD, respectively. This change indicates that CO2 is more movable and more of it is left trapped after geochemical reactions. scCO2 -brine relative permeability curves were obtained from history matching experimental results. To better understand and quantify estimates of the effect of relative permeability change on large-scale CO2 storage, simulations of CO2 injection were performed in a Madison Limestone reservoir model. Simulation results show that CO2 injectivity will be reduced and pressure-limited reservoirs will have reduced disposal capacity, though area-limited reservoirs may have increased capacity. Future reservoir-scale modeling efforts should incorporate the observed sensitivity in relative permeability on CO2 injection. Assuming applicability of the experimental results to other lithologies, accounting for the fact and that the majority of reservoirs are pressure