Production Performance of Multiple Completion Designs: Openhole, Slotted Liner, ICD, and AICD: A Case Study for Water Control in Villano Field, Ecuador

Abstract

This paper presents an analysis of the effectiveness of various downhole completion designs in reducing or deferring water production in a mature field under the presence of an active strong aquifer reservoir. The results of completions using nozzle inflow control devices (ICDs) and fluidic diode autonomous ICDs (AICDs) are compared with conventional openhole and slotted liner completions. As all of these designs were installed in the same field/reservoir, the comparisons provide a meaningful and representative analysis of well production performance to assist in the identification of the most appropriate completion design for future wells and the production optimization of existing ones. The designed vs. actual production performance of inflow control completions providing water control (ICD/AICD) is presented and discussed. The methodology was developed from comparative analysis results of conventional openhole and slotted liner vs. ICD and AICD completions. The analysis was primarily based on elapsed time comparisons for water/oil ratio (WOR) and water cut (WC) and used diagnostic plots to identify the water production mechanisms, historical drawdown (DD), productivity index (PI), and production cumulative performance (oil and water). The corrective actions are described, including operational procedures to reduce skin damage and screen plugging implemented in the Villano-23HST2 (V-23HST2) well, which is the longest horizontal well drilled in Ecuador and completed using AICDs; these corrective actions were based on lessons learned from the Villano-22D (V-22D) well, which included appropriate fluid [brine/oil-based mud (OBM)] conditioning, fluid displacement, filter cake removal, and compatibility testing between screens and the fluid in which the bottomhole assembly (BHA) was deployed. Additionally, this paper evaluates the importance of the design phase, emphasizing the importance of comparing preliminary data (permeability and water saturation) compared to actual results obtained from the initial production test. Finally, as good production results largely depend on successful operational procedures and execution, lessons learned and best practices for deploying downhole completions in future operations for the Villano field in Ecuador are discussed. Although many studies compare ICDs vs. conventional completions, few compare different inflow control technologies, such as ICDs vs. AICDs, within the same reservoir and with similar well conditions. This paper compares various inflow control technologies in the same field with cumulative production data, which verifies the effectiveness of each completion design. Based on these results, a validated methodology for ICD and AICD simulations and design is also described as the basis for achieving good production results.