Delayed breaking of gelled hydrocarbon fracturing fluid

Method of making a fracturing fluid useful in subterranean formation fracturing comprising adding to a hydrocarbon fracturing fluid a phosphoric acid ester and at least a stoichiometric amount of a polyvalent metal source selected from iron salts and aluminum compounds in amounts effective to form a gel in said fracturing fluid, and also adding to said fracturing fluid a slowly soluble gel breaker having a loss on ignition no greater than 0.5% in an amount effective to break said gel.

Composition useful in formation fracturing comprising a hydrocarbon fracturing fluid, a gelling agent comprising a polyvalent metal salt of a phosphoric acid ester made from a phosphoric acid ester and an aluminum compound or iron salt, a proppant, and a slowly soluble alkaline earth metal gel breaker in an amount effective to break a gel formed by said gelling agent in said hydrocarbon fracturing fluid.

Method of delayed breaking a gelled hydrocarbon in contact with an uncontrolled amount of water, said gelled hydrocarbon comprising a hydrocarbon and a gelling agent which can be broken by alkaline earth metals, comprising adding to said gelled hydrocarbon an amount of a slowly soluble alkaline earth metal compound effective to break said gelled hydrocarbon in contact with said water.

A hydrocarbon gel exhibiting retardation in breaking comprising a hydrocarbon selected from the group consisting of crude oil, Diesel oil and kerosene, about 0.2% to about 2.4% (based on the hydrocarbon) of a polyvalent metal salt of a phosphate ester having about 6 to about 36 carbon atoms, in an amount sufficient to viscosity said hydrocarbon and about two pounds to about fifteen pounds of a hard burned alkaline earth metal oxide selected from the group consisting of hard burned magnesium oxide, hard burned lime, and hard burned dolomitic lime per thousand pounds of hydrocarbon.