Successful Water Shut-Off Utilizing Lower Completion ICD+SSD – Actual Case Study of Marginal Oil Field of Onshore UAE

Abstract Marginal oil fields often experience critical and challenging periods to sustain oil rates above minimum economic thresholds. Mitigative measures such as installation of lower completions (LC) help to control water production (water shut-off) and sustain oil production. In SPE-211320-MS, clear definition of data driven based candidate screening process for LC was discussed in detail. This paper will elaborate actual examples on LC design, post LC installation evaluation and describe several key factors to be considered when designing the LC implementation. In addition, well performance-based metrics will be highlighted to showcase the success of water shut-off (WSO) utilizing the LC implementation. It is critical to collect key data prior to preparing the LC design, which will ultimately impact the success of the LC implementation. Fresh production logging data and available open hole logs should be appropriately mapped and placed on the same page to analyze any information supporting the LC design. A collaborative review amongst petroleum engineers, Petro-physicists and other disciplines is necessary to understand and agree on the final data to be used for the design. Subsequently, the LC simulation designs should attempt to match the current well conditions and production. The simulations should involve testing sensitivities with different ICD+SSD settings and locations to obtain the best and most suitable results. A favorable outcome from this work should be to reduce water cut as much as possible from the original performance. Post LC installation, well production performance will be reviewed to assess the effectiveness of the LC configuration to achieve the targeted water cut. If necessary, production logging will be run to confirm that all LC elements are functioning as per the design. Before implementing the LC, four (4) wells were tested for installing ESP (Electric Submersible Pump) without LC. The results were unexpectedly negative, with WC increasing to 60-80% within two months. This trial will serve as a baseline for reviewing the success of LC implementation. Up to date, LC has been deployed in 28 wells and the results were evaluated based on WC reduction, improved accessibility, and LC equipment functionality. The post-LC installation results were impressive and key findings were gathered to improve the LC design. Three (3) wells with successful water shut-off will be presented in this paper. There have been many lessons learned and derived best practices of LC implementation from this study. This success of water shut-off could copied to other Field in similar reservoir condition. Moreover, guidelines, best practices and documentation have been developed for both internal future marginal field developments and could be leveraged for other oilfield operators to plan successful water shut-off attempt.