Core-Scale Modeling and Numerical Simulation of Alanine-Based Deep Eutectic Solvent Flooding for Enhanced Oil Recovery: An Experimental and Simulation Case Study of the Mishrif Reservoir, West Qurna-2 Oil Field, Southern Iraq

This study investigates the performance of an amino acid deep eutectic solvent (ADES) made of alanine and choline chloride as a green displacement solvent to the Mishrif carbonate reservoir, based on a laboratory-calibrated numerical model. The goals were to measure the interfacial tension (IFT), and wettability response of the ADES/crude oil/carbonate system, to replicate the core flooding experiment in the CMG-STARS software. The IFT and contact angle show a decrease from 4.22 mN/m and 103° to 1.00 mN/m and 8.4°, respectively, as the concentration of ADES was raised from 0 to 250 ppm. A one-dimensional Cartesian model (50 x 1 x 1) maintaining the bulk volume, pore volume, cross-sectional area, and length of the cylindrical plug was developed in CMG-STARS; wettability alteration was modeled by linear interpolating between the oil-wet and water-wet relative permeability; and chemical retention was modeled by a CMG adsorption isotherm. Brine flooding recovered 58% of OOIP and reduced oil saturation from 0.690 to 0.290; tertiary ADES injection at 150 ppm raised recovery to 73%, an incremental 15 percentage points of OOIP and a 36% reduction of residual oil saturation to 0.186. The history-matched model reproduced the measured recovery factor within 5 percentage points and the differential pressure within 6.5 percentage points. The main contribution of this work is the integration of experimentally measured IFT and contact angle into relative permeability interpolation for ADES flooding in an Iraqi carbonate system and the demonstration that wettability alteration, rather than IFT reduction, controls the incremental recovery in this system.