Abstract:
The invention concerns an aqueous viscoelastic fracturing fluid for use in the recovery of hydrocarbons. According to the invention, the fluid comprises a viscoelastic surfactant and a hydrophobically-modified polymer wherein the concentration of the hydrophobically-modified polymer is comprised between its overlap concentration c* and its entanglement concentration ce.
Abstract:
The invention discloses a method of controlling fluid loss from a subterranean formation of a well bore. In a first aspect, the method is done by providing a treatment fluid made of an aqueous fluid and a hydrophobic polymer; and introducing the treatment fluid into the wellbore. In a second aspect, the method is done by providing a treatment fluid made of water and a water soluble polymer; providing in the treatment fluid a fluid loss additive having a hydrophobic polymer; using the treatment fluid in a well bore of a subterranean formation; allowing the treatment fluid to establish a permeable filter cake with the water soluble polymer in at least a portion of the well bore; and allowing hydrophobic polymer to enter into the filter cake to reduce permeability of the filter cake.
Abstract:
The invention provides a method for treating tight gas sand and shale subterranean formations, the method comprising: forming a solvent-surfactant blend by combining a solvent, a surfactant and a co-surfactant; adding a diluent to the solvent-surfactant blend to form a micro emulsion; wherein the wettability of the formation altered from water-wet to gas-wet, and the amount of water imbibed into the formation is reduced.
Abstract:
The invention provides a method of treating a sandstone-containing subterranean formation penetrated by a wellbore. The method is carried out by forming a slurry of a carrier fluid containing a viscosifying agent and encapsulated particles of a hydrogen fluoride source without settling of the particles. The carrier fluid may be an acid-based carrier fluid. The encapsulated hydrogen fluoride source may be encapsulated with a solid polymer acid precursor. The hydrogen fluoride source is present within the slurry in an amount of about 10% or more by weight of the slurry. The slurry is introduced into the wellbore at a pressure above the fracture pressure of the formation under conditions wherein the hydrogen fluoride source is released.
Abstract:
A method of treating a sandstone-containing formation penetrated by a wellbore is carried out by forming a treatment fluid comprising an aqueous fluid containing a hydrogen fluoride source and an amorphous silica precipitation inhibitor. The treatment fluid is introduced into the formation through the wellbore at a pressure below the fracture pressure of the formation to facilitate dissolution of formation materials, optionally as a single stage. The amorphous silica inhibitor may be a polycarboxylate and/or polycarboxylic acid, an organosilane or a phosphonate compound. The amorphous silica inhibitor may be capable of inhibiting precipitation of amorphous silica so that the treatment fluid contains at least about 500 ppm of silicon after at least about 100 minutes subsequent to the treatment fluid being introduced into the formation.
Abstract:
The invention concerns an aqueous viscoelastic fracturing fluid for use in the recovery of hydrocarbons. According to the invention, the fluid comprises a cleavable viscoelastic surfactant and a hydrophobically-modified polymer, wherein the cleavable surfactant comprises a head group and a hydrophobic tail of at least 18 carbon atoms connected through a degradable acetal, amide, ether or ester bond and wherein the concentration of the hydrophobically-modified polymer is comprised between its overlap concentration c* and its entanglement concentration ce.
Abstract:
A method of treating a sandstone-containing formation penetrated by a wellbore is carried out by forming a treatment fluid comprising an aqueous fluid containing a hydrogen fluoride source and an amorphous silica precipitation inhibitor. The treatment fluid is introduced into the formation through the wellbore at a pressure below the fracture pressure of the formation to facilitate dissolution of formation materials, optionally as a single stage. The amorphous silica inhibitor may be a polycarboxylate and/or polycarboxylic acid, an organosilane or a phosphonate compound. The amorphous silica inhibitor may be capable of inhibiting precipitation of amorphous silica so that the treatment fluid contains at least about 500 ppm of silicon after at least about 100 minutes subsequent to the treatment fluid being introduced into the formation.
Abstract:
Disclosed are methods of treating subterranean formations by first providing a suspension of colloidal particles prior to the injection of viscoelastic based treatment fluid, and injecting the treatment fluid into a well. The colloidal particles reduce fluid loss into the formation. According to a second embodiment, the treating fluid includes a hydrophobically-modified polymer, said hydrophobically-modified polymer being present at a concentration between approximately its overlap concentration c* and approximately its entanglement concentration ce. The method is particularly useful for fracturing operations in medium to high permeability formations.
Abstract:
The invention concerns an aqueous viscoelastic fracturing fluid for use in the recovery of hydrocarbons. According to the invention, the fluid comprises a viscoelastic surfactant and a hydrophobically-modified polymer wherein the concentration of the hydrophobically-modified polymer is comprised between its overlap concentration c* and its entanglement concentration ce.
Abstract:
It is proposed a method of treating a subterranean formation including providing a suspension of colloidal particles prior to the injection of a treating fluid based on an aqueous fluid comprising a thickening amount of a viscoelastic surfactant. The colloidal particles help to reduce fluid losses into the formation. According to a second embodiment, the treating fluid includes a hydrophobically-modified polymer, said hydrophobically-modified polymer being present at a concentration between approximately its overlap concentration c* and approximately its entanglement concentration ce. The method is particularly useful for fracturing operation in medium to high permeability formation.