The Advent of a Novel Selective Zonal Isolation with Thermosetting Gels

Abstract Chemical shut-off operations have the capability to remediate complex sweep unconformities particularly in mature reservoirs. Planning and executing those jobs require through understanding of sweep profile, wellbore dynamics and setting clear job objectives. Many chemicals were tried in the past decades, however, in recent years, thermosetting gels gained industry attention due to their superb physical characteristics. Those characteristics opened the door not only for great innovative applications but also making operations quicker and safer. This article delves into the practical and essential aspects to ensure successful and safe treatment targeting water and gas shut-off operations, as well as casing repairs utilizing thermosetting gels. Based on shut-off objectives, the gel type and required treatment volume are determined. The performance of the selected gel is then thoroughly evaluated in the laboratory and validated through yard testing to ensure that lab results can be replicated at the well site. During the intervention and prior to delivering the treatment volume, the treated zone is flushed to maximize the gelation process efficiency concurrently while conducting an injectivity test to assess the impact of the pumping rate on wellbore temperature. Based on observed wellbore temperature transients, the pumping schedule is optimized accordingly which is one of the critical advents of this new deployment method. Another key innovation in this new approach is to achieve simultaneous zone isolation while delivering the treatment to leave no residual gel or solid plugs that may restrict the wellbore or require post-treatment interventions. In addition to eliminating risk of getting stuck or plugging the wellbore, it reduces operation time significantly from days and weeks to less than a day and the well can be produced immediately after treatment. Overall, this approach represents a substantial advancement in chemical shut-off operations with thermosetting gels promoting efficiency, safety while meeting the evolving demands of mature reservoirs management.