摘要 |
A rubber member for downhole tools, preferably a sealing member, a ball sealer, a ball seat or a protecting member, which has a rate of decrease in 50% strain compressive stress of 5% or more, particularly preferably 50% or more, after being immersed in water having a temperature of 150°C for 24 hours; a downhole tool equipped with the rubber member; and a method for recovering a hydrocarbon resource using the downhole tool. |