Baker Hughes Corporation

Independence Oilfield Chemicals LLC

John Robert Willingham

James B Crews

Tianping Huang

James H Treadway

Allen Dale Gabrysch

Patrick Arthur Kelly

James R Pace

Christopher K Belcher

Richard Mitchell

Jeffrey Carl Dawson

William Russell Wood

Kushal Seth

Christopher George Burke

Matthew Kye Yocham

Chen Xiyuan

High viscosity fracturing fluids for fracturing a subterranean formulation are prepared by: (i) selecting recovered water; (ii) contacting said recovered water with a viscosifying agent, wherein said viscosifying agent is selected from fenugreek gum, tara gum, locust bean gum, guar gum and derivatives of the aforesaid; (iii) contacting said recovered water with one or more other additives for example with a cross-linking agent (A) for cross-linking said viscosifying agent, wherein contact of said recovered water with cross-linking agent (A) takes place when the pH of said recovered water is less than pH 6.5; (iv) adjusting the pH to pH 6.5-8.8.

Formulations comprising recovered water and a viscosifier and associated methods

A method of treating a subterranean formation penetrated by a well-bore, for example to facilitate fracturing of the formation, comprises the steps of: (i) selecting a treatment fluid comprising a diverting agent (A) in a flaked form, for example guar gum in a flaked form. (ii) introducing the treatment fluid into the subterranean formation via the well-bore to plug a region of the formation. Thereafter, the formation may be fractured or re-fractured.

Method for making a treatment fluid comprising a diverting agent in flake form, and method of treating a well

A fracturing fluid, gravel pack fluid and/or frac pack fluid containing particles such as proppants, gravel and/.or sand, may contain an effective amount of a nano-sized particulate additive to fixate or reduce fines migration, where the particulate additive is an alkaline earth metal oxide, alkaline earth metal hydroxide, alkali metal oxides, alkali metal hydroxides transition metal oxides, transition metal hydroxides, post-transition metal oxides, post-transition metal hydroxides piezoelectric crystals and pyroelectric crystals. The nano-sized particulate additive is optionally bound to the particles with a coating agent such as an oil, alcohol, glycol, glycol ethers, ketones, terpenes, etc. The particle size of the magnesium oxide or other agent may be nanometer scale but may be a larger scale than nanometer but still relatively small, which scale may provide unique particle charges that help fixate the formation fines. The carrier fluid used in the treating fluid may be aqueous, brine, alcoholic or hydrocarbon-based.

Nano-sized particle-coated proppants for formation fines fixation in proppant packs

Water production from a subterranean formation is inhibited or controlled by pumping a fluid containing coated particles through a wellbore into the formation. The particles have been previously coated with a relative permeability modifier (RPM). Upon contact with water, the RPM coating expands or swells and inhibits and controls the production of water. The RPM may be a water hydrolyzable polymer having a weight average molecular weight greater than 100,000. The particles may be conventional proppants or gravel.

Method of controlling water production through treating particles with RPMS

Emulsified acids have been used to increase production rates of oil and gas in carbonate reservoirs through acid fracturing and matrix acidizing operations. An emulsifier is used to emulsify the aqueous acid with an oil, usually diesel. Very small particles, such as colloidal clay particles and/or nanoparticles increase the stability of the emulsified acids over an elevated temperature range.

Stabilizing emulsified acids for carbonate acidizing

An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) is stabilized and improved with an effective amount of an alkaline earth metal oxide, alkaline earth metal hydroxide, alkali metal oxides, alkali metal hydroxides, transition metal oxides, transition metal hydroxides, post-transition metal oxides, and post-transition metal hydroxides. These fluids are more stable and have a reduced or no tendency to precipitate, particularly at elevated temperatures. The additives may reduce the amount of VES required to maintain a given viscosity. These stabilized, enhanced, aqueous viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in hydraulic fracturing. The particle size of the magnesium oxide or other agent may be nanometer scale, which scale may provide unique particle charges that use chemisorption, crosslinking and/or other chemistries to associate and stabilize the VES fluids.

Nano-sized particles for stabilizing viscoelastic surfactant fluids

An aqueous, viscoelastic fluid gelled with a viscosifier, e.g. a viscoelastic surfactant, is stabilized and improved with an effective amount of a particulate additive such as alkaline earth metal oxides, alkaline earth metal hydroxides, transition metal oxides, transition metal hydroxides, post-transition metal oxides, and post-transition metal hydroxides. These fluids are more stable and have a reduced or no tendency to precipitate, particularly at elevated temperatures, and may also help control fluid loss. These particulate additives have unique particle charges that use chemisorption, 'crosslinking' and/or other chemistries to associate and stabilize the VES fluids, and also help trap or fixate formation fines when placed in a gravel pack or a proppant pack in a fracture. Some of these effects may be more pronounced the smaller the size of the particulate additive.

Multifunctional particles for downhole formation treatments

Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES, an internal breaker, a VES stabilizer, a fluid loss control agent and a viscosity enhancer are useful as treating fluids and particularly as fracturing fluids for subterranean formations. These VES-based fluids have faster and more complete clean-up than polymer-based fracturing fluids. The use of an internal breaker permits ready removal of the unique VES micelle based pseudo-filter cake with several advantages including reducing the typical VES loading and total fluid volume since more VES fluid stays within the fracture, generating a more optimum fracture geometry for enhanced reservoir productivity, and treating reservoirs with permeability above the present VES limit of approximately 400 md to at least 2000 md.

Methods and compositions for fracturing subterranean formations

Nanoparticle-treated particle packs, such as sand beds, may effectively filter and purify liquids such as waste water. Proppant beds treated with nanoparticles may fixate or reduce fines migration therethrough. When tiny contaminant particles or fines in these fluids flow through the nanoparticle-treated bed or pack, the nanoparticles will capture and hold the tiny contaminant or fines particles within the pack due to the nanoparticles' surface forces, including, but not necessarily limited to van der Waals and electrostatic forces. Nanoparticle-treated beds or packs may be recharged by contacting the bed with an inorganic acid (but not hydrofluoric acid) or an organic acid, and optionally followed by subsequent treatment with hydrofluoric acid. This treating substantially removes the nanoparticles and the fine particulates that have been removed from a fluid (e.g. wastewater being treated, produced fluids in a formation, etc.). The particle pack may then be re-treated or recharged with nanoparticles.

Methods for recharging nanoparticle-treated beds

Viscoelastic surfactant (VES) based fluid systems are effective to pre-saturate high permeability subterranean formations prior to a treatment operation that would undesirably suffer from high fluid leakoff. The fluid systems may include brine, a viscosity enhancer, as well as the VES, and a high temperature stabilizer. The stabilizer may be an alkaline earth metal oxide, alkaline earth metal hydroxide, alkali metal oxide, alkali metal hydroxide, AlO, and mixtures thereof. The viscosity enhancer may include pyroelectric particles, piezoelectric particles, and mixtures thereof. The fluid system is easy to pump into the formation, and after initial pumping, the fluid system will soak into and occupy or 'pre-saturate' the pores of the formation prior to pumping of a second treating fluid for fracturing, gravel packing, frac-packing, and the like. The methods are practiced in the absence of acids typically used in acidizing operations, such as hydrochloric acid and hydrofluoric acid.

Methods of using viscoelastic surfactant gelled fluids to pre-saturate underground formations

Compositions including relatively low reactivity acids, mixed with viscoelastic surfactants (VESs) and internal breakers may serve as drilling fluids to open underground hydrocarbon reservoirs with carbonate contents of 10 wt % or above. The drilling fluids have low viscosities in the drilling pipe. After the fluid flows out of the drill bit, the acids react with carbonates in the formation thereby increasing the pH of the drilling fluids causing the VES to gel the fluid at the bottom of the hole and the downhole annulus between the drilling pipe and the formation rock. The viscosified drilling fluid will reduce fluid loss and will carry no dissolved drilling debris to the surface. After drilling through the targeted formation, the internal breakers in the viscosified drilling fluids will break down the fluids to permit their removal, and the well is ready to produce with very little or no near well bore damage.

Drilling fluids for oil and gas reservoirs with high carbonate contents

Viscoelastic surfactant (VES) based fluid systems for zone isolation and flow control are effective in water and/or gas shutoff applications. The fluid systems may include brine, a viscosity enhancer, as well as the VES, and optionally a stabilizer for high temperature applications. The stabilizer may be an alkali earth metal oxide, alkali earth metal hydroxide, alkali metal oxide, alkali metal hydroxide, AlO, and mixtures thereof. The viscosity enhancer may include pyroelectric particles, piezoelectric particles, and mixtures thereof. The fluid system is easy to pump into the formation, and after pumping, the fluid system will generate very high viscosities to prevent the VES fluid from flowing back to stop undesirable water and/or gas production.

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Cypress, TX, United States of America

John Robert Willingham