Coupled tripartite investigation of breaker fluid invasion and impact on hydrocarbon recovery in sandstone reservoirs

Abstract

Breaker fluids are designed to dissolve filter cakes by breaking their long-chain molecules, thereby removing solid deposits on the wellbore wall. Although breaker fluids are not intended to infiltrate the hydrocarbon reservoir, they can invade and cause formation damage by altering sandstone reservoirs' wettability and relative permeability. This can lead to a reduction in the overall reservoir performance. This study coupled tripartite methods to investigate the potential impact of breaker invasion and transport in hydrocarbon reservoirs and its multiscale effect on the performances of sandstone reservoirs. We utilized experimental, analytical, and numerical methods to assess and predict the susceptibility of reservoirs to breaker fluid invasion and transportation. Our experimental and empirical investigations considered varying breaker fluid formulations to evaluate the effects of breaker fluid concentration, formation temperature, and solution gas-oil ratio (GOR) on residual-oil saturation (ROS) and oil-water relative permeability. By adopting the ROS and relative permeability associated with the 50% v/v breaker fluid mixture, the performance of the hydrocarbon reservoir was numerically simulated under the limiting scenarios of no-invasion, moderate-invasion, and deep-invasion of breaker fluid. The results indicate a positive correlation between breaker fluid concentration and ROS, highlighting the risks that breaker fluid invasion and deep infiltration pose to hydrocarbon recovery. Further, results show that both live-oil condition (LOC) and dead-oil condition (DOC) reservoirs are susceptible to the detrimental impacts of breaker fluid infiltration, while their invasion can reduce hydrocarbon recovery in both LOC (−6%) and DOC (−28%). The multi-scale effects on reservoir performance are more pronounced at near-wellbore and DOC than at far-field and LOC. Findings from this work provide valuable insights into the complexity of breaker-fluid invasion in sandstone reservoirs and the mitigation of associated risks to reservoir performance.

Keywords

• Breaker fluid
• Fluid invasion
• Formation damage
• Fluid transport
• Near-wellbore alteration