Biopolymer consolidation of the near-wellbore zone and mobility control in the ACG field: A coupled two-phase hydrodynamic-geomechanical model
Ahmed Fariz Fikret, Mammadov Elnur Elkhan
https://doi.org/10.65294/gpogc.2026.27
This study presents a coupled two-phase hydrodynamic–geomechanical model of biopolymer treatment in fluvio-deltaic sandstones of the Azeri–Chirag–Gunashli (ACG) field. Unlike conventional polymer flooding models, which consider only changes in filtration properties and fluid mobility control, the proposed model incorporates the mechanism of mechanical stabilization of weakly cemented formations through biopolymer adsorption. The model integrates the governing equations of two-phase oil–water flow, accounting for concentration-dependent viscosity and permeability, adsorption kinetics based on the Langmuir isotherm, and a geomechanical component based on the Mohr–Coulomb failure criterion. Rock strengthening is implemented through an increase in effective cohesion proportional to the level of adsorbed biopolymer. The coupled system is solved numerically using the finite volume method (TPFA) and the IMPES scheme. Simulations performed for representative ACG reservoir conditions demonstrate that biopolymer concentrations of 300–400 mg/L reduce near-wellbore permeability from 500 mD to 70–120 mD and decrease the failure index by 25–40%. An optimal concentration of approximately 320 mg/L provides a balance between sweep efficiency improvement, fluid mobility control, and mechanical stability without significant injectivity impairment. The results demonstrate that the proposed model can be effectively applied for designing sand production prevention treatments and optimizing biopolymer flooding parameters in high-salinity, high-temperature reservoirs such as those of the ACG field.