Enhancing Well Integrity in the Middle East: Utilization of Novel Elastomeric Swelling Sleeve for Sustained Annular Pressure Prevention

Abstract Sustained Annular Pressure (SAP), a surface pressure buildup across one or multiple casing annuli as a result of fluid migration through permeating leaking barriers, originates from various factors including insufficient cement quality and progressive cement degradation over time. If not effectively managed, SAP can lead to critical well failures such as casing damage, thereby increasing the risk of well integrity failure and associated environmental impact. This issue presents a significant concern for the global oil and gas industry, as approximately 50% of wells over 15 years old exhibit at least one casing annulus with SAP buildup worldwide (Yousuf et al., 2021). The situation is therefore particularly critical in the Middle East, where more than 50% of wells exceed 25 years of age. Consequently, oilfield operators across the Middle East face ongoing difficulties managing SAP in aging assets while implementing preventative measures for new wells. These circumstances highlight the urgent need for comprehensive mitigation strategies to ensure operational safety and extend the lifespan of well assets. A novel and unique field-proven elastomeric swelling sleeve has been developed for the purpose of SAP prevention by sealing casing-to-cement micro annuli immediately upon exposure to fluid migration. Distinctly different from a swellable packer, the elastomeric swelling sleeve is a thin elastic seal designed for onsite slip-on installation onto oilfield tubulars. This high-value solution is capable of expanding and forming a reliable casing-to-cement seal when micro annular flow paths develop over time during the life of a well; it does not require additional downhole components, moving parts, or operational actuation for its activation. Developed in partnership with a major E&P company, the technology has been successfully field proven in over 500 global installations, including a 16-well shale-gas campaign. The elastomeric swelling sleeve provides enhanced value by effectively preventing gas migration across critical cement barriers, thereby eliminating the need for remedial cementing throughout the well's lifecycle. This capability leads to substantial capital and operational expenditure savings by streamlining decommissioning operations, particularly due to the absence of SAP buildup at the time of plug & abandonment. This publication offers a detailed description of the technology, highlighting its onsite installation process and examining its exceptional potential to mitigate SAP buildup occurrences across the Middle East region. Additionally, it discusses the development and qualification of an innovative CO2-swelling version of the technology, featuring the world’s first purpose-built CO2-swelling elastomer, specifically engineered to optimize well integrity in underground CO2 storage wells and oilfield applications subjected to bottom-hole temperatures up to 200°C (392°F).