RUBBER MEMBER FOR DOWNHOLE TOOLS, DOWNHOLE TOOL, AND METHOD FOR RECOVERING HYDROCARBON RESOURCE

摘要

A rubber member for downhole tools, preferably a seal member, ball sealer, ball seat, or protecting member, of which a decrease rate of 50% strain compressive stress after immersion for 24 hours in 150°C water relative to 50% strain compressive stress before immersion is not less than 5%, and preferably not less than 50%; a downhole tool comprising the rubber member; and a method for recovering a hydrocarbon resource using the downhole tool.