Impact of Three‐Phase Relative Permeability and Hysteresis Models on Forecasts of Storage Associated With CO₂‐EOR

Abstract

Geological CO2 sequestration in conjunction with enhanced oil recovery (CO2‐EOR) includes complex multiphase flow processes compared to CO2 storage in deep saline aquifers. Two of the most important factors affecting multiphase flow in CO2‐EOR are three‐phase relative permeability and associated hysteresis, both of which are difficult to measure and are usually represented by numerical interpolation models. The purpose of this study is to improve understanding of (1) the relative impacts of different three‐phase relative permeability models and hysteresis models on CO2 trapping mechanisms, and (2) uncertainty associated with these two factors. Four different three‐phase relative permeability models and three hysteresis models were applied to simulations of an active CO2‐EOR site, the SACROC unit located in western Texas. To eliminate possible bias of deterministic parameters, we utilized a sequential Gaussian simulation technique to generate 50 realizations to describe heterogeneity of porosity and permeability, based on data obtained from well logs and seismic survey. Simulation results of forecasted CO2 storage suggested that (1) the choice of three‐phase relative permeability model and hysteresis model led to noticeable impacts on forecasted CO2 sequestration capacity; (2) impacts of three‐phase relative permeability models and hysteresis models on CO2 trapping are small during the CO2‐EOR injection period, and increase during the post‐EOR CO2 injection period; (3) the specific choice of hysteresis model is more important relative to the choice of three‐phase relative permeability model; and (4) using the recommended three‐phase WAG (Water‐Alternating‐Gas) hysteresis model may increase the impact of three‐phase relative permeability models and uncertainty due to heterogeneity.

An Integrated Property–Performance Analysis for CO2-Philic Foam-Assisted CO2-Enhanced Oil Recovery

“…34 A recent study on the impact of hysteresis models on three-phase WAG simulation of a field sector model highlighted the sensitivity of the choice of hysteresis model rather than relative permeability models on simulation results. 35 To mitigate this limitation, it is recommended to calibrate the relative permeability model based on measurements or matching the history data to obtain a reliable prediction. Hence, understanding the active mechanisms involved in the SAG process aimed to be modeled is an important requirement in choosing the appropriate simulator and in modeling the process.…”

“…Hysteresis is defined as the different values of relative permeability and capillary pressure for a given saturation table as a result of saturation history . A recent study on the impact of hysteresis models on three-phase WAG simulation of a field sector model highlighted the sensitivity of the choice of hysteresis model rather than relative permeability models on simulation results . To mitigate this limitation, it is recommended to calibrate the relative permeability model based on measurements or matching the history data to obtain a reliable prediction.…”

Monitoring the CO2 enhanced oil recovery process at the nanoscale: an in situ neutron scattering study

“…5 This means that carbon capture and storage enhanced oil recovery (CCS-EOR) can be balanced with the dual objective of enhanced oil recovery whilst at the same time storing some of the injected CO 2 permanently in the depleted reservoir. [6][7][8][9][10][11] Finally, in a recent review study it was suggested that it is feasible to use CO 2 -EOR to enhance shale gas recovery instead of using conventional water-based fracturing fluids. It was then concluded that the process can be applied with the objectives of drilling, fracturing and sequestration.…”

Impact of Mineral Reactive Surface Area on Forecasting Geological Carbon Sequestration in a CO2-EOR Field

“…Existing uncertainty studies for GCS primarily focus on uncertainties stemming from porosity, permeability, and operational factors (e.g., injection scheme) [6,[14][15][16][17][18][19][20]. Only a few studies have examined the impact of uncertain reactive surface areas on GCS performances.…”