Breaking the Mold with an Innovative, High Performance Retrievable Bridge Plug for Wellbore Isolation Applications

Abstract This paper describes a method of overcoming fundamental limitations in conventional retrievable bridge plug (RBP) design to significantly improve oil and gas wellbore isolation operations. By eliminating both elastomer deformation to reach the seal bore and the reliance on elastomer memory to recover to gauge, we can address the industry's need for retrievability combined with the increased performance requirements of higher pressure, higher temperatures, and gas-tight barriers. This approach eliminates significant risks in NPT, well loss and well control and also enables the placement of high-performance retrievable plugs in previously inaccessible completions. To fundamentally change the trade-off between access, retrievability and performance in elastomer design a novel method of slicing a volume into constituent segments was developed. These segments can be re-arranged, without mechanical deformation, to fit into a smaller annular volume. This allows the construction of sealing elements and extrusion barriers that do not need to be deformed to reach the sealing bore, and do not rely on elastomer relaxation or memory to return to gauge diameter. This makes the retrievability of the plug independent of the material degradation issues that typically occur to the elastomer element downhole, particularly in high performance applications. This Segmented-Ring Technology forms the basis of a novel sealing system that has been developed offering higher performance (> 10,000 psi) at higher expansion ratios (20%) than any available wireline retrievable bridge plug on the market, thereby allowing High-Pressure, High Temperature (HPHT) gas-tight performance in restricted access completions. The elimination of elastomer memory as a recovery method greatly reduces recovery risks due to compression set, material degradation and Rapid Gas Decompression (RGD). The unique method of reconstructing the seal at the sealing diameter, paired with a modular plug architecture, also allows for new sizes of seal to be rapidly designed and deployed for specific applications. The new Segmented Ring sealing system has been successfully implemented on multiple plug sizes ranging from 3-1/2"to 7" sizes, and successfully deployed worldwide to address recovery issues and high performance through tight restriction requirements.