A review of fines migration around Steam Assisted Gravity Drainage wellbores

Abstract

This paper reviews the state-of-the-art experimental and theoretical methods on fines migration around Steam Assisted Gravity Drainage (SAGD) wellbores. The in-situ migratory particles can deposit in the pore space and result in pore throat plugging within the porous medium. This process damages the permeability around the sand control screen. This review includes field observations, experimental works, and simulations solving fines migration mathematically. Field observations indicate higher pressure differentials between the SAGD injector and producer due to the plugging of the sand control screen and surrounding formation. Coreflooding experiments confirm that the fines migration process is an essential contributing factor to the permeability damage near the SAGD wellbores. Macroscopic analytical models have also been extensively used at the lab-scale to predict the permeability variation by the fines migration. The modeling studies are focused mainly on consolidated sandstones, but the impact of sand control devices has not been incorporated. Many papers have been published to describe the influential factors controlling the fines migration process. However, the interaction between the wellbore completion and surrounding sand from the fines migration perspective has not been adequately explored. Despite numerous limitations in representing the reality near the SAGD wellbores, sand control testing procedures provide a short-term evaluation of the sand retention and flow performances of the sand control device in unconsolidated sand. However, these tests do not account for the transient behavior and long-term permeability variation caused by the fines migration process. This paper presents an integrated general-purpose procedure for the design of sand control devices in SAGD wells, addressing the gaps from this review.