Rapid Crosslinking Polymer Provides an Additional Blowout-Preventer Barrier

Abstract

SummaryThe industry maintains well control through proper well design and appropriate controls and barriers. This has made a hydrocarbon release from loss of well control a very–low–probability event. The current final barrier to maintain control is a valve system [blowout preventer (BOP)] located on top of wells, capable of isolating them by sealing around or shearing through obstructions that might be in the well (e.g., drillpipe and casing). Although the risk is low, there are still concerns regarding well control, especially for operations in sensitive environments. Adding an additional barrier could alleviate these concerns. We are currently evaluating a concept to respond to BOP seal failure by injecting a liquid monomer and a catalyst below a BOP leak point to rapidly form a polymer–plug seal.Mixtures of dicyclopentadiene (DCPD) and other monomers mixed with a ruthenium–based catalyst cause a rapid polymerization reaction that forms a stable solid. These reactions can occur under extreme temperatures and pressures and can withstand significant contamination from other fluids and solids.Laboratory studies showed that DCPD–based polymer plugs can withstand axial stress of 100 MPa (15,000 psi) without significant deformation, even at temperatures of 200°C and with 20 wt% synthetic–based–drilling–fluid contamination. Viscosity testing performed at 4°C showed that the liquid monomers and catalyst used to form polymers have viscosities low enough to allow rapid injection into a leaking BOP. Polymerization–reaction rates were not affected by the presence of high levels of drilling–fluid contamination or varying reaction temperatures. In all cases, reactions were rapid (less than 45 seconds) and resulted in the formation of solid polymers.