EXPERIMENTAL EVALUATION OF THE POTENTIAL IMPACTS OF POLYMER BREAKTHROUGH ON TOPSIDE OPERATIONS AT YARIGUÍ-CANTAGALLO FIELD CONDITIONS

Abstract

After a successful polymer injection pilot, Ecopetrol plans to deploy at full-field scale this enhanced oil recovery (EOR) technology on the Yariguí-Cantagallo field. Although a significant increase oil production is expected, the impact of the residual polymer on the produced water cycle should not be neglected. Indeed, after the polymer breakthrough, a significant part of the EOR chemical will be present in the produced fluids, and this may negatively impact the water/oil separation and the water treatment processes. An early review of this scenario provides an accurate vision of potential issues and, above all, enables to anticipate handling difficulties with produced fluids, and identifying mitigation strategies. This paper proposes a specific and comprehensive experimental methodology to assess production risks using laboratory equipment designed to mimic the current separation processes of the Yariguí-Cantagallo field, which were as representative as possible. The objective is to highlight the impact of the residual polymer first on water/oil separation processes with bottle tests, electrostatic dehydration tests, and polymer fouling evaluation on heat exchangers and, second, on water treatment using longterm gravity separation tests, Jar test, flotation column, and walnut shell filtration unit. The assessment considered different scenarios in terms of polymer concentration, water-cut, water composition and initial oil content in the produced water. The compatibility between the polymer and some oilfield chemicals, such as demulsifiers and water clarifiers, was also investigated.

Keywords

• eor
• polymer
• topside
• production risk
• emulsion produced water
• oil/water separation
• water treatment
• heater fouling