Hydraulic fracturing method

Claim 1

A method for the hydraulic fracturing of a subterranean formation surrounding a wellbore using an emulsified fluid which contains a minor volume proportion of a first liquid as the external phase and a major volume proportion of a second liquid as the internal phase, said method comprising the steps of passing said first liquid through an elongate conduit to establish a turbulent flow stream; continuously introducing said second liquid into said stream at a plurality of locations spaced along said conduit to provide a progressive increase in the volumetric concentration of said second liquid in said stream; continuously withdrawing said first and second liquids from said conduit as a commingled stream; and injecting said commingled stream through said wellbore and into said formation under sufficient pressure to open a fracture therein.

Claim 2

A method for the hydraulic fracturing of a subterranean formation surrounding a wellbore using an emulsified fluid which contains a minor volume proportion of a first liquid as the external phase and a major volume proportion of a second liquid as the internal phase, said method comprising the steps of passing said first liquid through an elongate conduit to establish a turbulent flow stream; continuously introducing said second liquid into said stream at a plurality of locations spaced along said conduit to provide a progressive increase in the volumetric concentration of said second liquid in said stream; continuously withdrawing said first and second liquids from said conduit as a commingled stream; and injecting said commingled stream through said wellbore and into said formation under sufficient pressure to open a fracture therein.

Claim 7

A method for the hydraulic fracturing of a subterranean formation surrounding a wellbore, said method comprising the steps of preparing an emulsion containing a major volume proportion of a first liquid as the external phase and a minor volume proportion of a second liquid as the internal phase; passing said emulsion through a conduit to establish a flow stream; continuously introducing into said stream at a plurality of locations spaced therealong additional volumes of said second liquid to progressively increase the concentration of said second liquid in said first liquid, the final concentration of said second liquid in said first liquid being more than about 50 volume percent but not more than about 80 volume percent; and thereafter injecting said first liquid containing said second liquid through said wellbore and into said formation at a pressure sufficient to open a fracture therein.

Claim 8

A method for the hydraulic fracturing of a subterranean formation surrounding a wellbore, said method comprising the steps of preparing an emulsion containing a major volume proportion of a first liquid as the external phase and a minor volume proportion of a second liquid as the internal phase; passing said emulsion through a conduit to establish a flow stream; continuously introducing into said stream at a plurality of locations spaced therealong additional volumes of said second liquid to progressively increase the concentration of said second liquid in said first liquid, the final concentration of said second liquid in said first liquid being more than about 50 volume percent but not more than about 80 volume percent; and thereafter injecting said first liquid containing said second liquid through said wellbore and into said formation at a pressure sufficient to open a fracture therein.

Claim 9

A method for continuously preparing an emulsified fracturing fluid and for injecting the same into a subterranean formation surrounding a wellbore, said method comprising the steps of placing a first liquid in a first container; placing a second liquid immiscible with said first liquid in a plurality of containers; equalizing the liquid levels in all of said containers; continuously discharging said first liquid from said first container into a conduit to establish a turbulent flow stream; continuously discharging said second liquid from said plurality of containers into said flow stream at a plurality of locations spaced along said elongate conduit to progressively increase the concentration of said second liquid in said first liquid; continuously maintaining the liquid levels in said containers at about the same level while said first and second liquids are being discharged into said conduit; continuously withdrawing said first and second liquids from said conduit as a commingled stream; and continuously injecting said commingled stream through said wellbore and into said formation at a pressure sufficient to open a fracture therein.

Claim 10

A method for continuously preparing an emulsified fracturing fluid and for injecting the same into a subterranean formation surrounding a wellbore, said method comprising the steps of placing a first liquid in a first container; placing a second liquid immiscible with said first liquid in a plurality of containers; equalizing the liquid levels in all of said containers; continuously discharging said first liquid from said first container into a conduit to establish a turbulent flow stream; continuously discharging said second liquid from said plurality of containers into said flow stream at a plurality of locations spaced along said elongate conduit to progressively increase the concentration of said second liquid in said first liquid; continuously maintaining the liquid levels in said containers at about the same level while said first and second liquids are being discharged into said conduit; continuously withdrawing said first and second liquids from said conduit as a commingled stream; and continuously injecting said commingled stream through said wellbore and into said formation at a pressure sufficient to open a fracture therein.

Claim 11

A method for the hydraulic fracturing of a subterranean formation which comprises passing an aqueous liquid containing an emulsifying agent capable of forming an oil-in-water emulsion through a substantially open conduit to establish a flow stream; introducing a hydrocarbon liquid into said flow stream at a plurality of locations spaced along said conduit to progressively increase the volumetric concentration of said hydrocarbon liquid in said stream, said hydrocarbon liquid mixing with said aqueous liquid to form an oil-in-water emulsion wherein said hydrocarbon liquid comprises a major volume proportion of said emulsion; and thereafter injecting said emulsion into said formation.

Claim 12

A method for the hydraulic fracturing of a subterranean formation which comprises passing an aqueous liquid containing an emulsifying agent capable of forming an oil-in-water emulsion through a substantially open conduit to establish a flow stream; introducing a hydrocarbon liquid into said flow stream at a plurality of locations spaced along said conduit to progressively increase the volumetric concentration of said hydrocarbon liquid in said stream, said hydrocarbon liquid mixing with said aqueous liquid to form an oil-in-water emulsion wherein said hydrocarbon liquid comprises a major volume proportion of said emulsion; and thereafter injecting said emulsion into said formation.

Claim 13

A method for the hydraulic fracturing of a subterranean formation which comprises preparing an emulsion containing a major volume proportion of an aqueous liquid as the external phase and a minor volume proportion of a hydrocarbon liquid as the internal phase, and an emulsifying agent capable of forming an oil-in-water emulsion; flowing said emulsion through a substantially open conduit to establish a flow stream; introducing into said stream at a plurality of locations spaced along said conduit additional volumes of said hydrocarbon liquid to progressively increase the concentration of said hydrocarbon liquid to more than 50 volume percent but not more than 80 volume percent of said emulsion; and thereafter injecting said emulsion into said formation.

Claim 14

A method for the hydraulic fracturing of a subterranean formation which comprises preparing an emulsion containing a major volume proportion of an aqueous liquid as the external phase and a minor volume proportion of a hydrocarbon liquid as the internal phase, and an emulsifying agent capable of forming an oil-in-water emulsion; flowing said emulsion through a substantially open conduit to establish a flow stream; introducing into said stream at a plurality of locations spaced along said conduit additional volumes of said hydrocarbon liquid to progressively increase the concentration of said hydrocarbon liquid to more than 50 volume percent but not more than 80 volume percent of said emulsion; and thereafter injecting said emulsion into said formation.