Extending the Frontiers of Well Clean-Up Through Microemulsion Fluids-Based Technology Application

Abstract

In oil & gas development projects, the target is to clean-up and put well onstream as quickly as possible. Apart from the economic benefits of early production, timely clean-up and well kick-off ensures that drill-in fluids and other materials used during drilling and completions do not create irreversible damage to the near wellbore region of the reservoir. In the FENE field there were 12 wells completed but not on production for over 20 years due to security and contractual challenges. These wells were drilled with water-based mud and left with filtered Seawater post completion. Given that the drill-in fluids, Seawater, and other materials were left in the wells for a long time, significant damage was suspected for the wells. These damage mechanisms include mud invasion, in-situ emulsion and water or emulsion blockage in the production interval. These identified damage mechanisms meant that the 12 wells require a dedicated clean-up with an optimal recipe to remove emulsion and other damages in the near wellbore. Conventional acid stimulation was initially proposed but was not endorsed due to suspected performance inefficiency and possible fluids-fluids incompatibility that could lead to further formation damage. After a comprehensive integrated review evaluating the potential damage mechanisms, a novel solution was identified which involves the use of a high-definition remediation fluid solution "a Micro-emulsion Fluid (MEF) Based Technology" to remove identified near wellbore damage. Prior to field execution, a rigorous laboratory test was performed with fluid samples from the wells and the result indicated good near-wellbore damage removal, reservoir fluids and Seawater compatibility. The MEF based technology has so far been successfully deployed in 9 wells (with the remaining 3 wells in plan) and has effectively removed suspected near wellbore and formation damage. The wells are currently on production with a 33% increase in performance above plan. This technical paper explains the process of candidate treatment selection, solution design, job execution, and production gains from deploying MEF based solution on these 9 wells executed till date.