Abstract: The present invention provides a water-based fluid, in particular for drilling, completion or for any other intervention in a well such as a hydrocarbon well, in which the viscosity is controlled by a system constituted by precipitated silica nanoparticles (A) associated with a water-soluble copolymer (B) comprising one or more water-soluble co-monomers (I) having little or no affinity for silica and one or more co-monomers (II) which absorb onto the silica. The invention is of particular application to the secondary recovery of hydrocarbons.

Abstract: The Invention relates to novel fluids and techniques to optimize/enhance the production of hydrocarbon from subterranean formations (e.g., “completion fluids”), in particular, fluids and techniques are disclosed and claimed which remove wellbore damage and near-wellbore damage in the form of coating formed from drilling and production-related operations (“filtercake”); the techniques can be applied either by themselves or in conjunction with other completion operations, such as gravel packing; preferred embodiments are chelating agent and enzyme systems in a viscoelastic surfactant (VES) matrix.

Abstract: A water-based drilling fluid (WBM) comprises as additive a reaction product of a polyhydroxyalkane and alkylene oxide. The polyhydroxyalkane is desirably based on a monosacchoride, and is preferably sorbitol. The alkylene oxide may comprise ethylene oxide (EO), propylene oxide (PO) and/or butylene oxide (BO). Good results have been obtained with additives including Sorbitol+18EO, Sorbitol+9PO, Sorbitol+4EO+6BO, Sorbitol+6EO+6BO, or Sorbitol+6BO. Drilling fluids in accordance with the invention have been found in laboratory tests to exhibit improved shale inhibition properties as compared with known polyol containing WBM, particularly in the absence of added potassium ions. This is environmentally advantageous.

Abstract: The invention relates to a method and to a tool for treating at least one wall in a critical zone of a borehole, in particular a borehole for development of a hydrocarbon, water, gas or analogous field, the method consisting in reinforcing the wall of the critical zone by a coating obtained from a base fluid which is pumped from the surface to a tool (1) to be projected against the wall of the critical zone where it forms the coating once it has set, the method being characterized in that it consists in storing at least one additive or activator in liquid form in a reservoir (R) of the tool (1), and in projecting the additive simultaneously with the base fluid against the wall of the critical zone via at least one injector (I) in order to activate setting of the base fluid.

Abstract: A wellbore fluid composition effective to reduce oil-containing residue and water wet wellbore surfaces is provided. The fluid composition comprises a terpene composition and a surfactant. Methods for use of the fluid composition as a single spacer or as a multiple spacer in conjunction with a second fluid are provided. Methods for use of the composition in reduction or removal of oil-containing residue from wellbore surfaces, as a clean-up fluid, in wellbore completions, as a displacement fluid, and in wellbore treatment are provided.

Abstract: Systems for retarding setting in an oilfield well cement slurry comprise a solution of a phosphonate selected from methylene phosphonic acid derivatives and a phosphate, in particular selected from the following salts or the corresponding acids: mono-phosphates (ortho-phosphates PO42; meta-phosphates PO3), acyclic poly-phosphates (pyrophosphates P2O74, tripolyphosphates P3O105) or cyclic poly-phosphates. The system preferably may also comprise a retarder booster and is more particularly applicable to cementing at low or medium temperatures.

Abstract: The present invention relates to novel methods to stimulate a hydrocarbon-bearing formation; in particular, techniques are disclosed for shooting perforations aligned with the direction of probable fracture propagation; this is followed by fracturing using a low viscosity fluid, preferably a viscoelastic surfactant-based fluid; the combination yields surprising results with respect to optimized fracture efficiency (i.e., ideal height, and half-length more closely approaches the true fracture length due to superior clean up properties of the fluids).

Abstract: A method of determining the shear threshold of a drilling mud consists in placing a detecting head with a spherical surface near to a porous wall, in pouring the drilling mud around the detecting head, in forcing the mud to pass through the porous surface so as to form a mud cake above the porous surface and around the detecting head which has a diameter D, and in measuring both the time required for the mud cake to reach a measurable or pre-determined height, and also the torque opposing rotation of the detecting head corresponding to that height.

Abstract: A technique for centralized processing of oilfield or waterfield engineering data for design and analysis from distributed locations is disclosed. In one aspect, the invention includes a method comprising: acquiring a plurality of oilfield or waterfield data; establishing a communications link between a client computing device to a server computing device; inputting data from the client computing device to the server computing device; processing the data at the server computing device; and communicating the results to the client computing device. In a second aspect, the invention includes a computing system, comprising: a client computing device; a server computing device interconnected with the client computing device; and an analysis tool resident on the server. The analysis tool includes a calculation engine capable of analyzing the data entered from the client computing device; and a plurality of program utilities for use by the calculation engine in analyzing the data.

Abstract: A method for continuously mixing a borehole fluid such as cement includes using a measurement of the solid fraction of a cement slurry as it is being mixed to determine the ratio of the solid and liquid components to be added to the slurry. A system for mixing the includes a liquid material (water) supply including a flow meter; a solid material (cement) supply; a mixer which receives the liquid and solid materials and includes an output for delivering materials from the mixer to a delivery system; a device for measuring the amount of material in the mixer; and a flow meter in the output; wherein measurements from the flow meters and the device for measuring the amount of material in the mixer are used to control the amount of solid and/or liquid material added to the mixer.

Abstract: A vehicle, such as a truck, includes mixing and pumping equipment for mixing a liquid and a particulate material (e.g., cement) and for pumping the mixture. One application is to pump the mixture into a wellbore for cementing a casing or liner to the wellbore inner wall. The vehicle includes a cab, with the mixing and pumping equipment positioned behind the cab. The equipment includes one or more reservoirs, with at least one used as both a mixing and displacement tank. A hose assembly is also positioned on the vehicle. To reduce the weight load placed on the rear axle(s) of the vehicle, relatively heavy components, such as the pump, are placed further forward on the truck. In one arrangement, the pump may be placed between the cab and the one or more reservoirs.

Abstract: Viscoelastic surfactant based aqueous fluid systems useful as thickening agents in various applications, e.g. to suspend particles produced during the excavation of geologic formations. The surfactants are zwitterionic/amphoteric surfactants such as dihydroxyl alkyl glycinate, alkyl ampho acetate or propionate, alkyl betaine, alkyl amidopropyl betaine and alkylimino mono- or di-propionates derived from certain waxes, fats and oils. The thickening agent is used in conjunction with an inorganic water-soluble salt or organic additive such as phthalic acid, salicylic acid or their salts.

Abstract: The slurries were prepared using a reference slurry having a density of 16.4 lb/gal(US) (1.965 g/cm3) of cement, with porosity of 55.18%. The cement was a class G Dickerhoff North cement. The slurries were prepared in the presence of on agent at a concentration of 0.4% by weight of cemenit (BWOC) and of an anti-foaming agent at a concentration of 0.03 gallons per (94 pound) sack of cement (gps); (a concentration of 0.1 gps corresponds to 0.90 liters of anti-foaming agent per 100 kg of cement). The suspension agent was added to the mixing water, and mixing took place at 4000 revolutions.

Abstract: Herein is described a method of consolidating a subterranean formation or repairing a gravel pack, comprising (i) providing a consolidating fluid, wherein the consolidating fluid comprises a gel component and a gel-forming agent; and (ii) injecting the consolidating fluid into the formation or gravel pack, under conditions wherein the gel component forms a flexible gel, thereby consolidating the formation.

Abstract: An acidic fluid that is useful in stimulation and workover operations, and in particular, for the control of iron in acidizing operations, the removal of alkaline earth carbonate scale in scale removal operations, and matrix or fracture acidizing operations, comprises an acid, such as hydrochloric acid; water; and a hydroxyethylaminocarboxylic acid. Preferred hydroxyethylaminocarboxylic acids are hydroxyethylethylenediaminetriacetic acid (HEDTA) and hydroxyethyliminodiacetic acid (HEIDA). Also disclosed herein are methods of controlling iron, removing alkaline earth carbonate scale, or matrix or fracture acidizing, involving the use of the acidic fluid.

Abstract: A method and apparatus for performing sand control using fracturing is described. A curve is defined that correlates the percentage of flow through out-of-phase perforations (those perforations not aligned with fractures) with the fracture conductivity over formation permeability. Given a desired production flow, formation conductivity may be defined. This allows the well operator to perform the proper fracturing operation to achieve the desired fracture conductivity. Alternatively, after a well has been fractured, and sand production is observed, a critical flow rate and the corresponding drawdown pressure can be calculated to prevent sand production.