High internal phase ratio water-in-oil emulsion fracturing fluid
AssigneeSchlumberger Technology Corporation
InventorsKay E. Cawiezel, Richard Hodge
Life of this patent
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Abstract
A high internal phase ratio water-in-oil emulsion containing an emulsifier comprising a block or graft copolymer the general formula (A-COO).sub.mB or a reaction product of a polyalk(en)yl succinic anhydride and a polar compound having at least one hydroxyl or amino group demonstrates surprisingly low pumping friction pressure losses, high temperature stability and excellent proppant carrying capacity for use as a fracturing fluid in the hydraulic fracturing of subterranean formation.
Claims21
A fracturing fluid for fracturing of subterranean formations comprising a high internal phase invert oil-based emulsion wherein the aqueous internal phase comprises at least seventy five percent of the emulsion and an external oil phase including an emulsifying agent for emulsifying the aqueous phase in the oil phase is selected from a group consisting of (a) an effective amount of a block or graft copolymer having the general formula (A-COO).sub.m B, wherein m is an integer of at least 2, A is a polymeric component having a molecular weight of at least five hundred and is the residue of an oil-soluble complex monocarboxylic acid and B is a polymeric component having a molecular weight of at least five hundred and comprises a water soluble polyalkylene glycol, (b) a reaction product of a polyalk(en)yl succinic anhydride and a polar compound having at least one hydroxyl or amino group and (c) mixtures thereof.
A method of fracturing a subterranean formation comprising the steps of:
- dissolving an effective amount of an emulsifier selected from a group consisting of (a) block or graft copolymer of the formula (A-COO).sub.m B wherein m is an integer of at least 2, A is a polymeric component having a molecular weight of at least five hundred and is the residue of an oil soluble complex mono-carboxylic acid and B is a polymeric component having a molecular weight of at least five hundred and comprises a water soluble polyalkylene glycol, (b) reaction product of a polyalk(en)yl succinic anhydride and a polar compound having at least one hydroxyl or amino group and (c) mixtures thereof;
- said emulsifier being dissolved in an oil phase;
- dispersing at least seventy five percent by volume aqueous phase in the oil phase to form an oil-external emulsion and
- pumping the fracturing fluid at fracturing pressure into a subterranean formation.
Dependencies are inferred from the claim text.