Abstract: A drilling fluid or mud is described wherein the drilling fluid contains at least one alkali metal formate or monovalent carboxylic acid salt. The drilling fluid preferably further contains at least one emulsifier or surfactant and at least one hydrocarbon-based fluid. The drilling fluids of the present invention can contain other conventional ingredients. The present invention permits drilling fluids to be essentially solids free due to the use of the alkali metal formate.

Abstract: A class of additives, that improve the viscosity and rheological properties of drilling fluids, are mixtures of materials comprising modified tannins, modified lignites, modified lignosulfonates and metal compounds including iron, tin, chrome, manganese, titanium, aluminum, or zinc. In one aspect, the invention is directed to improving the dispersion properties of those materials known as sulfoalkylated tannins, oxidized by a strong oxidation process in an alkali environment with oxygen, ozone, or an oxidizing agent including hydrogen peroxide, sodium perborate, sodium peroxycarbonate or mixtures thereof. In a further aspect the invention refers to an additive composition to improve the properties of drilling fluid, completion, and work-over fluids. The amount of additive to be added to the drilling, completion, or work-over fluid should be enough to reduce at least one of the parameters including: plastic viscosity; yield point; 10 second and 10 minute gels; or water-loss caused by filtering.

Abstract: Drilling fluid systems, graphite particle mixtures, and methods for use thereof including: (a) drilling fluid systems having effective rheology and lubricity properties comprising a suspension of graphite particles having a particle size distribution sufficient to permit greater than 65 wt. % of the graphite particles to pass through a shaker screen having a mesh size of about 80 or less; and (b) spotting fluids having effective rheology comprising graphite particles having an average particle size of 120 mesh or greater.

Abstract: A composition for oil and gas drilling fluids containing organic contaminants comprising: a solidification agent; cell transport agent; a cellulosic additive; and wherein said composition comprises enough solidification agent to enable the solidification agent to electrolytically attract the organic contaminates to the surface of the solidification agent when hydrated.

Abstract: Additives for drilling fluids, in particular for water-based drilling fluids are described which when added to the fluid at levels of up to 10% weight by volume reduces the accretion and bit-balling tendencies of shale cuttings exposed to said fluids. The additives are based on phosphonate chemistry, and are of the general class (I), wherein R, R′ and R″ are radicals exclusively containing H atoms or combinations of H, C, O or P atoms up to a maximum of 100 atoms.

Abstract: Zeolite compositions having enhanced compressive strength and methods therefor are provided. In particular, methods and compositions for wellbore treating fluids, especially settable spotting fluids having enhanced compressive strength are provided.

Abstract: Methods and compositions for wellbore treating fluids, especially settable spotting fluids, that include zeolite and at least one carrier fluid.

Abstract: A composition and method for treating oil and gas drilling fluids containing organic contaminants comprising: a solidification agent and a cellulosic additive; and wherein the composition comprises enough solidification agent to enable the solidification agent to electrolytically attract the organic contaminates to the surface of the solidification agent when hydrated.

Abstract: A composition and method for treating oil and gas drilling fluids containing organic contaminants comprising: a solidification agent, and a cell transport agent; wherein the composition comprises enough solidification agent to enable the solidification agent to electrolytically attract the organic contaminates to the surface of the solidification agent when hydrated.

Abstract: High fluid loss acid soluble lost circulation material and spotting pill comprising the lost circulation material. The spotting pill preferably is weighted to a density substantially the same as the drilling fluid used to treat the formation.

Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity of not less than 10 &mgr;S m−1 at 1 kHz comprises a polar organic liquid (POL) which exhibits a dielectric constant of at least about 5.0 and a Hildebrand Solubility Parameter of at least about 17 (J cm−3)1/2. Oils or other organic liquids (OL) known to be suitable as the continuous liquid phase of wellbore fluids, may be used in admixture with POL component. Certain inorganic salts, organic bases, quaternary ammonium salts or hydroxides (the dissolved component, DC), display sufficient solubility (and current carrying abilities) in POL, OL or in mixtures of liquid (POL) and liquid (OL) to further improve the electrical conductivity of the mixture. The wellbore fluid can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.

Abstract: A drilling fluid additive is provided wherein the additive is manufactured by a method comprised of admixing colloidal solids such as talc with a combination of oil and glycol or cellulose to create a suspended mixture to thereby allow the colloidal solids to be pre-wet, treated or coated with the oil/glycol combination or the cellulose; and then admixing copolymer beads to the suspended mixture.

Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity increased by a factor in order of 104 to 107 compared to conventional invert emulsion comprises from about 0.2% to about 10% by volume of carbon black particles and one or more emulsifying surfactant(s) selected from the class including nonionic emulsifiers of Hydrophilic-Lipophilic Balance (HLB) less than about 12, and anionic surfactants wherein the counter-ion (cation) is any of alkali metal, ammonium, or hydrogen ions. This wellbore fluid can be used for drilling or completing a well and can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.

Abstract: Methods of drilling and completing open hole well bores and methods of removing filter cake comprised of a gelling agent and calcium carbonate are provided. A method of the invention for removing filter cake comprised of a gelling agent and calcium carbonate from the walls of an open hole well bore is basically comprised of the steps of contacting the filter cake with a delayed clean-up solution comprised of water and a formate ester and removing the clean-up solution from the well bore.

Abstract: A method is provided for reducing loss of drilling fluid and for stabilizing a wellbore during drilling through depleted sands in a subterranean formation comprising depleted sands. The method comprises introducing into said wellbore and into said depleted sands an aqueous fluid comprising silicate or siliconate and resilient graphitic carbon in an amount effective at substantially plugging pores in said depleted sands.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: A drilling fluid additive system is provided wherein the system is manufactured by a method comprised of admixing colloidal solids such as talc with a carrier such as oils and glycols or talc with cellulose to create a suspended mixture to thereby allow the colloidal solids to be pre-wet or coated with the carrier; and then admixing copolymer beads to the suspended mixture to allow the beads to be pre-wet or coated with the carrier; and then adding the suspended mixture with a mixture comprised of hydrophilic clay, a pH controller, a fluid loss controller, and a dispersant.

Abstract: A drilling fluid additive system is provided wherein the system is manufactured by a method comprised of admixing colloidal solids such as talc with a carrier such as oils or glycols to create a suspended mixture to thereby allow the colloidal solids to be pre-wet or coated with the carrier; and then admixing copolymer beads to the suspended mixture to allow the beads to be pre-wet or coated with the carrier; and then adding the suspended mixture with a mixture comprised of hydrophilic clay, a pH controller, a fluid loss controller, and a dispersant.

Abstract: A method for enhancing the stability of a solids-stabilized water-in-oil emulsion by pretreating the oil prior to emulsification. The pretreatment step can be accomplished by adding dilute acid to the oil, adding a lignosulfonate additive to the oil, sulfonating the oil, thermally oxidizing the oil, thermally treating the oil in an inert environment, and combinations thereof. The emulsion can be used in enhanced oil recovery methods, including using the emulsion as a drive fluid to displace hydrocarbons in a subterranean formation, and using the emulsion as a barrier fluid for diverting flow of fluids in the formation.

Abstract: Environmentally acceptable well cement fluid loss control additives, cement compositions including the additives and methods of using the compositions are provided. The environmentally acceptable fluid loss control additives are comprised of ethoxylated hydroxyethylcellulose having a reduced molecular weight.

Abstract: Methods of consolidating formations or forming chemical casing or both while drilling are provided. One method of the invention comprises drilling a well bore with a drilling fluid comprised of water, a polymeric cationic catalyst which is adsorbed on weak zones or formations formed of unconsolidated clays, shale, sand stone and the like, a water soluble or dispersible polymer which is cross-linked by a thermoset resin and causes the resin to be hard and tough when cured, a particulate curable solid thermoset resin, a water soluble thermoset resin, and a delayed dispersible acid catalyst for curing the solid and water soluble resins. The drilling fluid forms a filter cake on the walls of the well bore that cures and consolidates the unconsolidated weak zones and formations penetrated by the well bore so that sloughing is prevented and forms a hard and tough cross-linked chemical casing on the walls of the well bore.

Abstract: The present invention provides lightweight cement compositions, and methods for cementing in a subterranean formation using such cement compositions. The cement compositions comprise hydrated lime, vitrified shale, and sufficient water to form a slurry. Optionally, other ingredients may be included in the compositions.

Abstract: Methods of consolidating formations or forming chemical casing or both while drilling are provided. One method of the invention comprises drilling a well bore with a drilling fluid comprised of water, a polymeric cationic catalyst which is adsorbed on weak zones or formations formed of unconsolidated clays, shale, sand stone and the like, a water soluble or dispersible polymer which is cross-linked by a thermoset resin and causes the resin to be hard and tough when cured, a particulate curable solid thermoset resin, a water soluble thermoset resin, and a delayed dispersible acid catalyst for curing the solid and water soluble resins. The drilling fluid forms a filter cake on the walls of the well bore that cures and consolidates the unconsolidated weak zones and formations penetrated by the well bore so that sloughing is prevented and forms a hard and tough cross-linked chemical casing on the walls of the well bore.

Abstract: Low concentrations, 1-10% of potassium salt, especially potassium formate, are used in a drilling fluid in oil production. Preferably they are used with guar derivatives, most preferably carboxymethyl hydroxypropyl guar. The concentration of potassium formate is maintained at the desired level by adjusting the potassium formate to maintain a desired Zeta potential in the circulating drilling fluid. The potassium formate/guar derivative composition may be used in the substantial absence of hydrophilic clay additive.

Abstract: Improved methods of generating gas in and foaming aqueous well fluids introduced into a subterranean zone are provided. A method of the invention includes the steps of combining with an alkaline aqueous well fluid one or more gas generating chemicals and a mixture of foaming and foaming stabilizing surfactants so that the gas generating chemical or chemicals react with the alkaline aqueous well fluid and gas and foam are formed in the well fluid while it is being pumped, and then pumping the well fluid into the subterranean zone.

Abstract: Improved silicate drilling fluids are produced by the addition of tetra alkyl ammonium compounds, in particular tetra methyl ammonium hydroxide to silicate drilling fluid mud to lower the co-efficient of friction between drill string and wellbore. It has also been discovered that the same tetra alkyl ammonium lubricant compounds greatly lessen the viscosity breakdown of swelled hectorite clay in the presence of silicate. This allows the preparation of silicate drilling fluids not only with enhanced lubricity but having stable rheology at the higher temperature and pressures encountered in some drilling operations.

Abstract: The present invention generally relates to compositions of matter and methods of using those compositions. More particularly, and as part of one of the preferred embodiments, the present invention relates to compositions and methods of use of fluids useful for sealing formation fractures and/or inhibiting downhole fluid loss. The present invention is useful as a pill or series of pills that can be formulated and spotted to a particular formation zone.

Abstract: High fluid loss acid soluble lost circulation material and spotting pill comprising the lost circulation material. The spotting pill preferably is weighted to a density substantially the same as the drilling fluid used to treat the formation.

Abstract: An improved composition and method is provided for preventing or alleviating lost circulation during the drilling of wellbores in subterranean formations, and particularly during the drilling of oil and gas wells. The method is suited for horizontal and directional wells as well as more vertical wells. The composition of the invention comprises a synergistic blend of resilient, angular, carbon-based material and a water-swellable, crystalline synthetic polymer. The method employs the composition of the invention in preventing lost circulation.

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: An additive which increases the density of wellbore fluids used during the construction or repair of oil, gas, injection, water or geothermal wells comprises solid colloidal particles of weight average particle diameter (D50) of less than 2 microns, the particles being deflocculated by the action of a dispersant, preferably incorporated during the process of grinding or communication of the particles to the specified particle size. The additives may be used in any wellbore fluid such as drilling, cementing, completion, packing, work-over (repairing), stimulation, well killing and spacer fluids as well as in a dense media separating fluid or in a ship's ballast fluid.

Abstract: This invention discloses methods for reducing lost circulation in wellbores. The invention utilizes certain selected water swellable polymers that swell at a rate slow enough to reach the lost circulation zone of a well before those polymers have swollen to an extent that disrupts the drilling process. These selected polymers may be used alone or in conjunction with other lost circulation materials which do not swell or also swell slowly enough to reach the lost circulation zone without interfering with the drilling operation. Mixtures of such materials are also disclosed.

Abstract: A water-base drilling fluid for use in drilling wells through a formation containing a shale which swells in the presence of water.

Abstract: Disclosed is a method of increasing the low shear rate viscosity and the shear thinning index of aqueous fluids containing a divalent cation salt, a crosslinked amylopectin starch which functions as both a viscosifier/suspending agent and as a fluid loss control additive, and a bridging agent, the fluids resulting from the method, and the use of the fluids in drilling a well, wherein the bridging agent is a sized particulate magnesium carbonate or a mixture of sized magnesium carbonate and sized calcium carbonate. The median (D50) particle size of the magnesium carbonate is from about 2 &mgr;m to about 10 &mgr;m. The weight ratio of calcium carbonate to magnesium carbonate is from about 70/30 to about 0/100.

Abstract: Drilling fluid additives are designed to increase the density of drilling fluids while minimizing the increase in the resistance to flow of the drilling fluid. In particular, barite particles are added to the drilling fluid as a weight material where the barite particles include at least 85% by weight particles less than 75 microns and greater than 6 microns in equivalent spherical diameter.

Abstract: Composition of water-based drilling fluids characterized in that they comprise anions with a high hydrodynamic radius.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid basically comprised of water, a water soluble salt and a particulate solid bridging agent selected from magnesium oxychloride cement, magnesium oxysulfate cement, magnesium potassium phosphate hexahydrate, magnesium hydrogen phosphate trihydrate and magnesium ammonium phosphate hexahydrate. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with an aqueous clean-up solution for a period of time such that the bridging agent is dissolved thereby.

Abstract: A water-base drilling fluid for use in drilling wells through a formation containing a shale which swells in the presence of water. The drilling fluid preferably includes: an aqueous based continuous phase, a weight material, and a shale hydration inhibition agent having the formula: H2N—R—{OR′}x—Y in which R and R′ are alkylene groups having 1 to 6 carbon atoms and x is a value from about 1 to about 25. The Y group should be an amine or alkoxy group, preferably a primary amine or a methoxy group. The shale hydration inhibition agent should be present in sufficient concentration to reduce the swelling of the shale. Also inclusive of the present invention is a method of reducing the swelling of shale clay encountered during the drilling of a subterranean well, the method comprising circulating in the well a water-base drilling fluid formulated in accordance with the present invention.

Abstract: The present invention provides improved early-enhanced strength cement compositions and methods. The cement compositions can be utilized in surface construction projects as well as in the construction of oil, gas and water wells. The improved cement compositions of this invention are basically comprised of a hydraulic cement, water present in an amount sufficient to form a slurry and hydrophobic silica powder.

Abstract: A method for the rheology control of fluid phases, in which adducts which contain layered mixed metal hydroxides (MMH) and hectorite are used, and corresponding compositions for this purpose are claimed. Preferably used MMH are those which were produced by hydration of mixed metal oxides or oxyhydroxides, which in turn may be thermally activated. The use of coprecipitated MMH or of MMH produced in situ is also possible. The ratio of MMH to the hectorite component should preferably be from 0.05 to 0.2:1, it also being possible to use adducts whose clay fraction contains up to 80%. by weight of clays differing from hectorite, in particular bentonite. The method is preferably carried out using drilling fluids in the high-temperature range >300° F. (>149° C.).

Abstract: Conventional organophilic clays, when used as rheological additives in oil based invert muds, display marked viscosity loses in the mud when these muds are heated much above 350° F., whereas muds prepared according to the present invention are dramatically more viscosity stable at temperatures through 500° F. The present invention relates to the discovery of oil based invert emulsion drilling fluids that provides more stable drilling fluid viscosity and anti-settling performance over varying temperatures when compared to conventional fluids containing organoclays. As a result, the inventive fluids of this invention are ideal candidates for high temperature applications. This invention in another aspect of this invention is a process for improving the rheological properties of oil well drilling fluids particularly useful for oil-based invert emulsion types of drilling fluids.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: An excavation fluid composition useful for enlarging a cavity in the earth includes a synthetic polymer and sodium silicate. The excavation fluid composition is formulated so as to enable the fluid in contact with unstable or sandy soils in the selected areas of the excavation to react and form silicate-based derivatives with lesser solubility, and movement and thus improve soil stability at the excavation wall.

Abstract: A new composition for a spotting fluid and a method of using such spotting fluid for freeing differential stuck pipe in a subterranean well drilling operation is disclosed. The composition comprises an invert water-in-oil emulsion comprising iso-butyl oleate as its external phase and glycerin as the internal phase. In an alternative embodiment, calcium chloride and water may be substituted for glycerin.

Abstract: Disclosed is a method for producing a predetermined cesium compound. The method comprises treating a cesium-containing material with a suitable reagent to dissolve at least a portion of the cesium contained in the material and form a slurry; adding a base comprising slaked lime or calcium carbonate and an acid containing the anion of the predetermined cesium compound to the slurry comprising the dissolved cesium; and separating the predetermined cesium compound.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: A water-base fluid for use in drilling wells and other drilling operation includes a shale which swells in the presence of water.

Abstract: The invention relates to a composition comprising an HPHT fluid loss control aid, stable at elevated temperatures and which also acts as an excellent shale stabilizer, bore hold lubricant, sealant for depleted sand, and wall cake conditioner. The HPHT fluid loss control aid broadly comprises a uintaite sold under the trade name Gilsonite®, which also contains a surfactant such as a nonionic surfactant. The HPHT fluid loss control aid also contains a solubilized lignite such as causticized lignite and carbon black. The fluid loss control aid reduces HPHT filtrate loss, has good stability at elevated temperatures such as at 300° F., stabilizes troublesome shales and decreases bore hole erosion, helps seal depleted sands, reduces torque and drag, causes no adverse effects on the flow properties of the properly conditioned drilling fluid, and lowers total well costs.

Abstract: The invention provides clay-free, preferably biopolymer free, well drilling and servicing fluids comprising an aqueous divalent cation-containig water soluble salt, a bridging agent, and a pre-gelatinized crosslinked amylopectin starch suspending agent and fluid loss control additive. The concentration of the starch derivative is sufficient to provide the fluid with the following charactristics: (a) a low shear rate viscosity less than about 10,000 centipoise; (b) a high shear rate viscosity at 511 sec−1 in the range from about 15 to about 70 centipoise measured at 120° F.; (c) a fluid loss less than about 10 milliliters as measured at 185° F. and 250 psi differential pressure across a 5 micron disk for 30 minutes; and (d) anti-settling characteristics as exhibited upon static aging the fluid for 16 hours at 185° F.

Abstract: Suspension, having a high storage stability, comprising an aqueous silicate solution and a filler material, wherein the silicate solution has a silicate content of at least 20% by weight, the filler material has an average particle size of 0.8 to 15 &mgr;m and a specific weight of below 2.75 Kg/l.