A method of preparing a polymer-sand nanocomposite for water shutoff. The method includes applying a surface polymerization to sand particles. The surfaced polymerization formed by combining a polymerization initiator dissolved in a solvent with the sand particles to form a precursor sand mixture, combining a co-monomer and additional polymerization initiator in the presence of graphene, where the graphene is not functionalized, to form a precursor polymer mixture, and combining the precursor sand mixture and the precursor polymer mixture to form a sand-copolymer-graphene nanocomposite. The method further includes drying the sand-copolymer-graphene nanocomposite, preparing a polymer hydrogel, and combining the polymer hydrogel and the sand-copolymer-graphene nanocomposite to crosslink the components and form the polymer-sand nanocomposite. The associated method of forming a barrier to shut off or reduce unwanted production of water in a subterranean formation utilizing the polymer-sand nanocomposite is also provided.

A method of preparing a polymer-sand nanocomposite for water shutoff. The method includes applying a surface polymerization to sand particles. The surfaced polymerization formed by combining a polymerization initiator dissolved in a solvent with the sand particles to form a precursor sand mixture, combining a co-monomer and additional polymerization initiator in the presence of graphene, where the graphene is not functionalized, to form a precursor polymer mixture, and combining the precursor sand mixture and the precursor polymer mixture to form a sand-copolymer-graphene nanocomposite. The method further includes drying the sand-copolymer-graphene nanocomposite, preparing a polymer hydrogel, and combining the polymer hydrogel and the sand-copolymer-graphene nanocomposite to crosslink the components and form the polymer-sand nanocomposite. The associated method of forming a barrier to shut off or reduce unwanted production of water in a subterranean formation utilizing the polymer-sand nanocomposite is also provided.

A method of preparing a polymer-sand nanocomposite for water shutoff. The method includes applying a surface polymerization to sand particles. The surfaced polymerization formed by combining a polymerization initiator dissolved in a solvent with the sand particles to form a precursor sand mixture, combining a co-monomer and additional polymerization initiator in the presence of graphene, where the graphene is not functionalized, to form a precursor polymer mixture, and combining the precursor sand mixture and the precursor polymer mixture to form a sand-copolymer-graphene nanocomposite. The method further includes drying the sand-copolymer-graphene nanocomposite, preparing a polymer hydrogel, and combining the polymer hydrogel and the sand-copolymer-graphene nanocomposite to crosslink the components and form the polymer-sand nanocomposite. The associated method of forming a barrier to shut off or reduce unwanted production of water in a subterranean formation utilizing the polymer-sand nanocomposite is also provided.

A method of preparing a polymer-sand nanocomposite for water shutoff. The method includes applying a surface polymerization to sand particles. The surfaced polymerization formed by combining a polymerization initiator dissolved in a solvent with the sand particles to form a precursor sand mixture, combining a co-monomer and additional polymerization initiator in the presence of graphene, where the graphene is not functionalized, to form a precursor polymer mixture, and combining the precursor sand mixture and the precursor polymer mixture to form a sand-copolymer-graphene nanocomposite. The method further includes drying the sand-copolymer-graphene nanocomposite, preparing a polymer hydrogel, and combining the polymer hydrogel and the sand-copolymer-graphene nanocomposite to crosslink the components and form the polymer-sand nanocomposite. The associated method of forming a barrier to shut off or reduce unwanted production of water in a subterranean formation utilizing the polymer-sand nanocomposite is also provided.

A method of preparing a polymer-sand nanocomposite for water shutoff. The method includes applying a surface polymerization to sand particles. The surfaced polymerization formed by combining a polymerization initiator dissolved in a solvent with the sand particles to form a precursor sand mixture, combining a co-monomer and additional polymerization initiator in the presence of graphene, where the graphene is not functionalized, to form a precursor polymer mixture, and combining the precursor sand mixture and the precursor polymer mixture to form a sand-copolymer-graphene nanocomposite. The method further includes drying the sand-copolymer-graphene nanocomposite, preparing a polymer hydrogel, and combining the polymer hydrogel and the sand-copolymer-graphene nanocomposite to crosslink the components and form the polymer-sand nanocomposite. The associated method of forming a barrier to shut off or reduce unwanted production of water in a subterranean formation utilizing the polymer-sand nanocomposite is also provided.

A method of preparing a polymer-sand nanocomposite for water shutoff. The method includes applying a surface polymerization to sand particles. The surfaced polymerization formed by combining a polymerization initiator dissolved in a solvent with the sand particles to form a precursor sand mixture, combining a co-monomer and additional polymerization initiator in the presence of graphene, where the graphene is not functionalized, to form a precursor polymer mixture, and combining the precursor sand mixture and the precursor polymer mixture to form a sand-copolymer-graphene nanocomposite. The method further includes drying the sand-copolymer-graphene nanocomposite, preparing a polymer hydrogel, and combining the polymer hydrogel and the sand-copolymer-graphene nanocomposite to crosslink the components and form the polymer-sand nanocomposite. The associated method of forming a barrier to shut off or reduce unwanted production of water in a subterranean formation utilizing the polymer-sand nanocomposite is also provided.

A method of preparing a polymer-sand nanocomposite for water shutoff. The method includes applying a surface polymerization to sand particles. The surfaced polymerization formed by combining a polymerization initiator dissolved in a solvent with the sand particles to form a precursor sand mixture, combining a co-monomer and additional polymerization initiator in the presence of graphene, where the graphene is not functionalized, to form a precursor polymer mixture, and combining the precursor sand mixture and the precursor polymer mixture to form a sand-copolymer-graphene nanocomposite. The method further includes drying the sand-copolymer-graphene nanocomposite, preparing a polymer hydrogel, and combining the polymer hydrogel and the sand-copolymer-graphene nanocomposite to crosslink the components and form the polymer-sand nanocomposite. The associated method of forming a barrier to shut off or reduce unwanted production of water in a subterranean formation utilizing the polymer-sand nanocomposite is also provided.

This invention provides an envelope configuration for retreading tires using a cold-retreading process. Envelopes formed by two parts are known in the prior art. However, the known sealing means between parts are not satisfactory, either due to sealing problems or due to decreasing the envelope useful life. In order to overcome these limitations, this invention provides an envelope (20) comprised of two parts (22, 24), in which an end region (224a) of a flap (224) of the first part (22) is covered by an end region (244a) of a flap (244) of the second part (24), or vice-versa, in order to form an overlapping joint, in which a free end of the flap (224) of the first part (22) has at least one differentiated cross section (224b) whose thickness is greater than that of the flap (224) of the first part (22), and in which the overlapping joint is covered by an elastic ring (26) that is wide enough to cover said differentiated cross section (224b).

This invention provides an envelope configuration for retreading tires using a cold-retreading process. Envelopes formed by two parts are known in the prior art. However, the known sealing means between parts are not satisfactory, either due to sealing problems or due to decreasing the envelope useful life. In order to overcome these limitations, this invention provides an envelope (20) comprised of two parts (22, 24), in which an end region (224a) of a flap (224) of the first part (22) is covered by an end region (244a) of a flap (244) of the second part (24), or vice-versa, in order to form an overlapping joint, in which a free end of the flap (224) of the first part (22) has at least one differentiated cross section (224b) whose thickness is greater than that of the flap (224) of the first part (22), and in which the overlapping joint is covered by an elastic ring (26) that is wide enough to cover said differentiated cross section (224b).

Methods of making anti-sticking perfluorinated articles are described. The methods include molding curing, and heat-treating a composition prepared from a coagulated and dried blend of latex dispersions of a perfluoro-elastomeric gum and a perfluoroplastic. The curing steps are performed at temperatures below the melting point of the perfluoroplastic, while the heat-treatment step occurs at a temperature above this melting point. The resulting articles are also described.