Abstract: Embodiments of the Present Invention relate to a reversibly thickenable non-polymeric fluid that has low viscosity in strong acid, gels when the acid concentration is reduced by only a small amount, and is subsequently decomposed by the acid. In particular it relates to an aqueous mixture of zwitterionic surfactants, inorganic acids, and organic acids Most particularly it relates to the use of this fluid as a diverting agent for easily-damaged sandstones, for example prior to matrix acidizing.

Abstract: The present invention relates to aqueous oilfield treatment fluids containing a gas component and fibers, wherein the fluids may further include a viscosifying agent and/or proppant. The fluids have good proppant suspension and transport properties as well as excellent gas phase stability. Use of fluids comprising an aqueous medium, a gas component, viscosifying agent, and fibers for hydraulically fracturing a subterranean formation, cleanup operations, and gravel packing a wellbore, are also disclosed.

Abstract: Subterranean treatment formation using a model which takes into account the pore level physics by coupling the local pore scale phenomena to the macroscopic variables (Darcy velocity, pressure and reactant cup-mixing concentration) through the structure-property relationships (permeability-porosity, average pore size-porosity and interfacial area-porosity) and the dependence of the fluid-solid mass transfer coefficient and fluid phase dispersion coefficient on the evolving pore scale variables (average pore size, local Reynolds and Schmidt numbers).

Abstract: The invention discloses a method of treating a zone of a well comprising a wellbore, a tube which is permeable to settable material, said tube forming an annulus with the wellbore; and wherein said zone is located in the annulus, the method comprises the steps of: (i) placing inside said tube a first plug; (ii) creating on said tube a first opening and a second opening, so that: the zone be located between said first and second openings and the first opening be located between said zone and said first plug; (iii) placing inside said tube a second plug, so that said second plug is located between said second opening and said zone; (iv) injecting a settable material inside said tube between said second and first plugs, so that settable material fills the annulus and the zone by passing through the first opening; and (v) eliminating said second plug.

Abstract: A differential filter includes a swellable polymer that swells after contacting water such that permeability of the differential filter is reduced. A method of controlling water production in a well includes deploying a differential filter downhole; and performing a downhole operation, wherein the differential filter comprises a swellable polymer that swells after contacting water such that permeability of the differential filter is reduced.

Abstract: An injection apparatus for injecting an activated fluid and an activated chemical fluid mixture into a well-bore is disclosed. Then, an injection method for injecting an activated fluid into a well-bore is also disclosed. A particular application to the oilfield industry, for example in cementing operation is encompassed. The apparatus and the method of use is fully automatic.

Abstract: A method of improving injectivity of fluid, particularly produced water, in enhanced hydrocarbon recovery is disclosed. The method includes introducing a fracturing fluid into the subterranean formation to create a fracture, and introducing proppant into the fracturing fluid to form a single layer of proppant in the fracture. The fracturing fluid can be formed from produced water. Alternatively, the produced water is introduced after a fracturing fluid, other than the produced water, has been introduced to create a fracture. By reducing the amount of proppant and by using much larger proppant, a larger flow path through the fracture is created, thereby increasing the injectivity of produced water.

Abstract: A method is provided for treating a subterranean formation penetrated by a well bore comprising the steps of: a) forming a phosphate ester gelled hydrocarbon fracturing fluid comprising a liquid hydrocarbon and a an alkyl phosphate gelling agent; b) adding said fluid a delayed gel breaker, c) injecting said fluid down a well, and d) allowing said breaker to break the fracturing fluid gel after an initial delay period and destabilize a metal crosslink in said gel, reducing the volatile phosphorous present in the fluid by at least about 25%.

Abstract: The present invention relates to novel aqueous wellbore treatment fluids containing a gas component, a heteropolysaccharide, an electrolyte, and a surfactant, wherein the fluids may further include an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures. Methods of use of fluids comprising at least an aqueous medium, a gas component, a heteropolysaccharide and a surfactant for hydraulically fracturing, well cleanup and gravel packing operations, are also disclosed.

Abstract: Disclosed are methods of modeling stimulation treatments, such as designing matrix treatments for subterranean formations penetrated by a wellbore, to enhance hydrocarbon recovery. The modeling methods describe the growth rate and the structure of the dissolution pattern formed due to the injection of a treatment fluid in a porous medium, based on calculating the length scales for dominant transport mechanism(s) and reaction mechanism(s) in the direction of flow lX and the direction transverse to flow lT. Methods of the invention may further include introducing a treatment fluid into the formation, and treating the formation.

Abstract: A dry solid composition is disclosed that, when added to an aqueous liquid, provides a slurry that can be used in sandstone acid fracturing. The slurry generates hydrofluoric acid downhole to etch the sandstone fracture faces created. The chemical and physical properties of the composition result in very uneven etching of the fracture faces, enhancing the fluid conductivity of the final fracture. Optionally, inert masking materials may be included in the dry composition, or added to the slurry, to increase the inhomogeneity of the etching and further increase the fluid conductivity.

Abstract: A method of stabilizing an underground formation surrounding a borehole comprising placing a treatment fluid in the formation, the treatment fluid comprising cross-linkable polymer and a cross-linking agent, and allowing the treatment fluid to gel in-situ, characterized in that after placement of the treatment fluid in the formation, an activator fluid is pumped into the well to bring about cross linking of the polymer to form the gel.

Abstract: The present invention relates to novel aqueous wellbore treatment fluids containing a gas component, a heteropolysaccharide, an electrolyte, and a surfactant, wherein the fluids may further include an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures. Methods of using fluids containing at least an aqueous medium, a gas component, a heteropolysaccharide and a surfactant for hydraulically fracturing, well cleanup and gravel packing operations, are also disclosed.

Abstract: A viscoelastic gelled oil, for example gelled diesel or paraffin oil, is made with a gelling agent, for example a phosphate ester, a metal carboxylate, for example an aluminum carboxylate, and a gel-enhancing surfactant, for example a zwitterionic surfactant, for example erucylamidopropyl betaine. The gel-enhancing surfactant makes the gel viscoelastic, increases the stability and decreases the sensitivity to the concentrations of the gelling agent and the metal carboxylate. The enhanced viscoelastic gelled oils are used, as examples, in hydraulic fracturing, frac packing, gravel packing, diversion, fluid loss control, lost circulation control, sand control, wellbore cleanout, wellbore or pipeline sweeping, organic scale dissolution, organic scale removal, and drilling.

Abstract: A method, practiced by a Hydraulic Fracturing Simulator software, is adapted for simulating a hydraulic fracture in an Earth formation, the formation including a multilayered reservoir, a mesh adapted to overlay the fracture in the formation thereby defining a plurality of elements, the mesh and the fracture defining one or more partially active elements, the method comprising the step of: setting up an Influence Coefficient Matrix, the matrix having a plurality of numbers, the plurality of numbers of the Influence Coefficient Matrix being calculated and determined such that the method, practiced by the Hydraulic Fracturing Simulator software for simulating the hydraulic fracture, models, or take into account an existence of, the multilayered reservoir and the partially active elements.

Abstract: In the presence of certain polyols, a guar gum or similar polysaccharide thickener solution is boron crosslinked before achievement of complete hydration of the thickener, without compromising the viscosity level achieved in a fracturing fluid by the time it is pumped into the wellbore and fractures the subterranean formation adjacent the wellbore. Methods continuously involve hydrating a polysaccharide thickener to an extent of 10% to 75%, but less than full hydration. Before 75% hydration is exceeded, a boron crosslinker is added. Upon addition of the boron crosslinker, the fluid is injected into the wellbore to stimulate hydrocarbon production. Because less time is needed for hydration, well site mixing equipment is down-sized smaller to achieve better efficiency and cost savings.

Abstract: The present invention relates to novel aqueous wellbore treatment fluids containing a gas component, a heteropolysaccharide, an electrolyte, and a surfactant, wherein the fluids may further include an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures. Methods of use of fluids comprising at least an aqueous medium, a gas component, a heteropolysaccharide and a surfactant for hydraulically fracturing, well cleanup and gravel packing operations, are also disclosed.

Abstract: A composition and method are given for self-destructive fluid loss additives and filter cakes in wellbores and subterranean formations. The fluid loss additives and filter cakes are formed from a mixture of particulate solid acid-precursors, such as a polylactic acid or a polyglycolic acid, and particulate solid acid-reactive materials, such as magnesium oxide or calcium carbonate. In the presence of water, the solid acid-precursors hydrolyze and dissolve, generating acids that then dissolve the solid acid-reactive materials. The composition is used in oilfield treatments such as drilling, completion and stimulation where it disappears when it is no longer needed without the use of mechanical means or injection of additional fluids.

Abstract: The invention relates to composition particularly suitable for squeeze cementing operations at temperature above 160 ° C. This composition comprises an aqueous base, a liquid set-retarder and a solid phase including a blend of micro fine alumina, micro fine silica and a micro fine cementitious material.

Abstract: A cement composition for which the mechanical properties of the set cement can be controlled independently of the slurry density, both at high density (>16 ppg) and at low density (<12 ppg) comprises a trimodal blend of particulate materials present as fine, medium and coarse particule size fractions, the particulate materials including cement, flexible particles, and a filler, characterized in that the cement comprises the fine particle size fraction, and the flexible particles and filler comprise the medium and large particle size fractions.