Abstract: Downhole tools comprising a body, wherein at least a portion of the body is degradable when exposed to a wellbore environment; and at least one oil-degradable sealing element composed of an oil-degradable elastomer, wherein the oil-degradable sealing element degrades in the wellbore environment. The oil-degradable elastomer is selected from the group consisting of an oil-degradable natural rubber, an oil-degradable synthetic rubber, and any combination thereof.

Abstract: Downhole tools comprising a body and at least one sealing element, wherein at least a portion of the body is degradable when exposed to a wellbore environment; and a retention mechanism configured to retain the sealing element in place during degradation of the portion of the body that is degradable, wherein the downhole tool is capable of actuating to fluidly seal two sections of the wellbore with the sealing element.

Abstract: Downhole tools comprising a body, wherein at least a portion of the body is degradable when exposed to a wellbore environment; and at least one aqueous-degradable sealing element comprising an aqueous-degradable elastomer comprising in the range of 0.05 to 1 parts by weight per hundred parts of the elastomer (phr) carbodiimide, wherein at least a portion of the aqueous-degradable sealing element hydrolytically degrades when exposed to an aqueous fluid.

Abstract: A well seal tool includes a base tubing and a seal element carried on an exterior of the base tubing. The seal element includes a polymer changeable between a compressed state and a sealing state. The seal element has a first stiffness in response to a first strain rate of the polymer and a second, substantially higher stiffness in response to a second, higher strain rate of the polymer.

Abstract: A wellbore cementing plug includes a plug element including a polymer. The polymer is deformable at a first stiffness when subjected to a first strain rate to allow the plug element to pass through a wellbore while sealing against passage of cement past the plug element. The polymer resists deformation at a second, higher stiffness when subjected to a second, higher strain rate to resist allowing the plug element to pass through the wellbore while sealing against passage of cement past the plug element.

Abstract: A well system includes a drop plug element and an internal plug seat in an internal flow path of a well tubing. At least one of the plug seat or the drop plug element includes a polymer that is deformable, having a first stiffness when subjected to a first strain rate, to allow the drop plug element to pass through the plug seat. The polymer resists deformation, having a second, higher stiffness when subjected to a second, higher strain rate, to resist allowing the plug element to pass through the plug seat and to seal the plug element and plug seat.