Plugging materials for vertical fractures

Claim 1

A METHOD OF INCREASING THE PERMEABILITY TO FLUID FLOW IN ONLY AN UPPER PORTION OF A VERTICAL FRACTURE IN A SUBSURFACE EARTH FORMATION TRANSVERSED BY A WELL BORE, WHICH METHOD COMPRISES FORMING A FIRST MIXTURE OF A FIRST CARRIER FLUID AND A WATER-INSOLUBLE, PARTICLE-FORM MATERIAL HAVING A MINIMUM DIMENSION AT LEAST AS GREAT AS 0.03 INCH AND AN AVERAGE PARTICLE STRANGTH OF LESS THAN 10 POUNDS PER PARTICLE AND SELECTED FROM THE GROUP CONSISTING OF COAL, COKE, BRITTLE PLASTICS, BRITTLE GLASS, RUBBER, PLIABLE PLASTICS, TAR AND HYDROGENATED VEGETABLE OILS, AND MIXTURES THEREOF, SAID PARTICLE-FORM MATERIAL HAVING A SETTLING RATE THROUGH SAID FIRST CARRIER FLUID IN EXCESS OF 0.1 FOOLT PER MINUTE, INJECTING SAID FIRST MIXTURE INTO SAID WELL BORE, THENCE TO SAID FORMATION AND INTO A FRACTURE WHOSE WALLS WILL EXERT SUFFICIENT FORCE TO CAUSE SAID PARTICLE-FORM MATERIAL TO UNDERGO PHYSICAL ALTERATION, FORMING A SECOND MIXTURE OF A SECOND CARRIER FLUID AND A FACTURE PROPPING AGENT AND INJECTING SAID SECOND MIXTURE INTO SAID WELL BORE THENCE TO SAID FORMATION AND INTO SAID FRACTURE, AND CEASING INJECTION OF SAID SECOND CARRIER FLUID TO PERMIT SAID FRACTURE TO CLOSE.

Claim 2

A METHOD OF INCREASING THE PERMEABILITY TO FLUID FLOW IN ONLY AN UPPER PORTION OF A VERTICAL FRACTURE IN A SUBSURFACE EARTH FORMATION TRANSVERSED BY A WELL BORE, WHICH METHOD COMPRISES FORMING A FIRST MIXTURE OF A FIRST CARRIER FLUID AND A WATER-INSOLUBLE, PARTICLE-FORM MATERIAL HAVING A MINIMUM DIMENSION AT LEAST AS GREAT AS 0.03 INCH AND AN AVERAGE PARTICLE STRANGTH OF LESS THAN 10 POUNDS PER PARTICLE AND SELECTED FROM THE GROUP CONSISTING OF COAL, COKE, BRITTLE PLASTICS, BRITTLE GLASS, RUBBER, PLIABLE PLASTICS, TAR AND HYDROGENATED VEGETABLE OILS, AND MIXTURES THEREOF, SAID PARTICLE-FORM MATERIAL HAVING A SETTLING RATE THROUGH SAID FIRST CARRIER FLUID IN EXCESS OF 0.1 FOOLT PER MINUTE, INJECTING SAID FIRST MIXTURE INTO SAID WELL BORE, THENCE TO SAID FORMATION AND INTO A FRACTURE WHOSE WALLS WILL EXERT SUFFICIENT FORCE TO CAUSE SAID PARTICLE-FORM MATERIAL TO UNDERGO PHYSICAL ALTERATION, FORMING A SECOND MIXTURE OF A SECOND CARRIER FLUID AND A FACTURE PROPPING AGENT AND INJECTING SAID SECOND MIXTURE INTO SAID WELL BORE THENCE TO SAID FORMATION AND INTO SAID FRACTURE, AND CEASING INJECTION OF SAID SECOND CARRIER FLUID TO PERMIT SAID FRACTURE TO CLOSE.