New methodology to predict operational limit of hydrogenated acrylonitrile butadiene rubber packer element for downhole application in energy industry

Abstract

AbstractHydrogenated acrylonitrile butadiene rubber (HNBR) has been widely used in many products that serve as sealing components for downhole operations in the energy industry, especially downhole permanent packers. A reliable methodology needs to be developed to predict operational limits for the elastomer during various tool deployments and operations. These operational limits are mostly based on laboratory life prediction tests derived from industry standards meant for material selection or screening. However, the conventional life prediction method cannot capture the effect of size/shape/stress and adequately predict the sealing performance of an actual elastomeric component under downhole operations. To fill this gap, a lifetime prediction methodology for a downhole HNBR packer was developed based on fundamental material behavior such as viscoelasticity, hyperelasticity, chemical/physical degradation from laboratory aging tests, and finite element analysis. Thereafter, the proposed methodology was used to develop an operational limit for the downhole packer in completion brine, calcium bromide. The results showed that the proposed methodology was not limited to the size or shape of the elastomeric product and can be readily extended to develop a successful operational limit for various elastomeric components in the energy industry.