Conventional retrievable bridge plug (RBP) designs have remained largely unchanged for decades, typically relying on a solid elastomer sealing element, slips, and a locking mechanism mounted on a central mandrel. In high-pressure, sour unconventional wells, these legacy designs can be challenged by extreme differential pressure, aggressive downhole conditions, and reliable retrieval requirements. This paper presents a novel retrievable bridge plug design deployed to enable efficient, reliable, single-run wellbore isolation in UAE unconventional wells.
Traditional RBP performance limitations are commonly associated with elastomer stress, seal deformation, and material degradation under harsh downhole conditions. During retrieval, these plugs rely on the ability of the elastomer element to recover and return to gauge, which can be compromised after prolonged exposure to pressure, temperature, and sour service. To address these challenges, a novel seal construction was developed using segmented ring technology, replacing conventional solid seals and slips with an interlocked segment array. This design eliminates expansion stress on the elastomer, preserves sealing integrity, and improves sealing capability by removing expansion-ratio limitations imposed by elastomer material properties.
The novel RBP design has been successfully deployed in more than 37 wells across UAE unconventional field operations, including wells with supercharged post-fracturing formation pressures exceeding 13,000 psi. Several gas wells also contained H2S concentrations exceeding 4%, creating an extreme sour-service environment that presents significant challenges for conventional RBP designs.
This study covers 57 setting runs and 38 retrieval runs across 37 wells, completed over 1.5 years of project execution. Despite the operational intensity and harsh downhole environment, the plug achieved an exceptional success rate of over 98%, demonstrating consistent setting, isolation, and retrieval reliability. The ability to set and retrieve the plug in a single run via slickline enabled the operation to be completed within 6 hours, minimizing impact on multi-well pad efficiency and avoiding disruption to the broader fracturing and intervention schedule.
The segmented ring design proved particularly valuable in unconventional wells, where post-fracturing wellbore irregularity, restricted internal diameter, and casing deformation may be encountered. The design's ability to accommodate over-travel and under-travel improved operational flexibility and supported reliable retrieval under variable wellbore conditions.
The successful application of this novel retrievable bridge plug design in high-pressure, sour unconventional wells expands the operating envelope, enabling gas-tight wellbore isolation. Its segmented ring sealing system and modular cartridge architecture enable component customization based on pressure, sour-service severity, and wellbore conditions, supporting rapid deployment for more challenging and field, specific applications in the future.
