Abstract: Minimizing circulating pressure loss and/or reducing friction in drilling fluid operations to minimize equivalent circulating density (ECD) and maximize flow for borehole cleaning, tool optimization and efficient drilling may be achieved by the addition of friction improvers or drag reducers while circulating drilling fluids. Suitable drag reducers may include, but not necessarily be limited to, poly(alpha-olefins); polyisobutylene; condensation polymers of dicarboxylic acids or anhydrides, or polyols and monocarboxylic acids, addition polymers of unsaturated esters; copolymers of alpha-olefins with unsaturated esters; polystyrene acylated with long chain fatty acids; polyalkylene oxides; copolymers of alkyl acrylates with N-containing olefins; and combinations thereof.

Abstract: Pumpable multiple phase vesicle compositions carry agents and components downhole or through a conduit, and controllably releasing them at a different place and time by breaking the compositions. In one non-limiting embodiment the pumpable multiple phase vesicles have a third phase containing a first phase which bears the agent to be controllably released. The first and third phases of the vesicles are separated by a surface active material bilayer that forms the second phase. The pumpable multiple phase vesicles may have internal and external phases that are both oil miscible, both aqueous miscible, or both alcohol miscible. The surface active material bilayer may be composed of compounds such as phospholipids, alkyl polyglycosides, gemini surfactants, sorbitan monooleate, sorbitan trioleate, and many others. The agent may be released by one or more of a variety of mechanisms.

Abstract: To improve drilling performance, a drilling fluid is selected based on one or more criteria and to have at least one target characteristic. Drilling equipment is used to drill a wellbore, and the selected drilling fluid is provided into the wellbore during drilling with the drilling equipment. The at least one target characteristic of the drilling fluid includes an ability of the drilling fluid to penetrate into formation cuttings during drilling to weaken the formation cuttings.

Abstract: To improve drilling performance, a drilling fluid is selected based on one or more criteria and to have at least one target characteristic. Drilling equipment is used to drill a wellbore, and the selected drilling fluid is provided into the wellbore during drilling with the drilling equipment. The at least one target characteristic of the drilling fluid includes an ability of the drilling fluid to penetrate into formation cuttings during drilling to weaken the formation cuttings.

Abstract: Pumpable multiple phase vesicle compositions carry agents and components downhole or through a conduit, and controllably releasing them at a different place and time by breaking the compositions. In one non-limiting embodiment the pumpable multiple phase vesicles have a third phase containing a first phase which bears the agent to be controllably released. The first and third phases of the vesicles are separated by a surface active material bilayer that forms the second phase. The pumpable multiple phase vesicles may have internal and external phases that are both oil miscible, both aqueous miscible, or both alcohol miscible. The surface active material bilayer may be composed of compounds such as phospholipids, alkyl polyglycosides, gemini surfactants, sorbitan monooleate, sorbitan trioleate, and many others. The agent may be released by one or more of a variety of mechanisms.

Abstract: Pumpable multiple phase vesicle compositions carry agents and components downhole or through a conduit, and controllably releasing them at a different place and time by breaking the compositions. In one non-limiting embodiment the pumpable multiple phase vesicles have a third phase containing a first phase which bears the agent to be controllably released. The first and third phases of the vesicles are separated by a surface active material bilayer that forms the second phase. The pumpable multiple phase vesicles may have internal and external phases that are both oil miscible, both aqueous miscible, or both alcohol miscible. The surface active material bilayer may be composed of compounds such as phospholipids, alkyl polyglycosides, gemini surfactants, sorbitan monooleate, sorbitan trioleate, and many others. The agent may be released by one or more of a variety of mechanisms.

Abstract: The invention concerns a method for determining the particle size distribution (PSD) of bridging agents in fluids, particularly aqueous fluids used in hydrocarbon recovery such as drilling fluids, drill-in fluids, completion fluids, and the like. It was discovered that the PSD could be selectively determined for calcium carbonate as a bridging agent because it auto-fluoresces. The method is reproducible and is not bothered by the presence of other particles such as drill solids which interferes with conventional methods, for instance, light-scattering techniques. The light used to fluoresce the bridging agent may be filtered to a particular frequency if there are other components present that fluoresce. Flow cytometry is another technique that could be used to implement the invention.

Abstract: A water-based drilling fluid having a polymer latex capable of providing a deformable latex film on at least a portion of a subterranean formation has been discovered to provide reduced drilling fluid pressure invasion when used to drill in shale formations for hydrocarbon recovery operations. A precipitating agent such as a silicate or an aluminum complex (e.g. sodium aluminate) is preferably used in conjunction with the polymer. Typically, the water present contains a salt to form a brine, often to saturation, although the invention may be practiced with fresh water. If a salt is employed, it is often helpful to additionally employ a surfactant, such as a betaine, for example.

Abstract: The invention concerns a method for determining the particle size distribution (PSD) of bridging agents in fluids, particularly aqueous fluids used in hydrocarbon recovery such as drilling fluids, drill-in fluids, completion fluids, and the like. It was discovered that the PSD could be selectively determined for calcium carbonate as a bridging agent because it auto-fluoresces. The method is reproducible and is not bothered by the presence of other particles such as drill solids which interferes with conventional methods, for instance, light-scattering techniques. The light used to fluoresce the bridging agent may be filtered to a particular frequency if there are other components present that fluoresce. Flow cytometry is another technique that could be used to implement the invention.

Abstract: Pumpable multiple phase compositions for carrying agents and components downhole and controllably releasing them by breaking the suspensions are described. The multiple phase composition may have an external or third phase, which in turn has a first pumpable emulsion internally. The first pumpable emulsion has a second phase containing a first phase which bears the agent to be controllably released. The entire pumpable multiple phase composition may thus be an oil phase-in-aqueous phase-in-oil phase emulsion, or an aqueous phase-in-oil phase-in-aqueous phase emulsion. The agent may be released by one or more of a variety of mechanisms. For example, a water-soluble shale stabilizer could be delivered downhole in an aqueous phase-in-oil phase-in-aqueous phase multiple phase emulsion by injecting the multiple phase composition into a water-based drilling fluid, and then the suspension broken by rotary bit nozzles under high shear stress to release the shale stabilizer at the drilling zone.

Abstract: A water-based drilling fluid having a polymer latex capable of providing a deformable latex film on at least a portion of a subterranean formation has been discovered to provide reduced drilling fluid pressure invasion when used to drill in shale formations for hydrocarbon recovery operations. A precipitating agent such as a silicate or an aluminum complex (e.g. sodium aluminate) is preferably used in conjunction with the polymer. Typically, the water present contains a salt to form a brine, often to saturation, although the invention may be practiced with fresh water. If a salt is employed, it is often helpful to additionally employ a surfactant, such as a betaine, for example.

Abstract: Pumpable multiple phase compositions for carrying agents and components downhole and controllably releasing them by breaking the suspensions are described. The multiple phase composition may have an external or third phase, which in turn has a first pumpable emulsion internally. The first pumpable emulsion has a second phase containing a first phase which bears the agent to be controllably released. The entire pumpable multiple phase composition may thus be an oil phase-in-aqueous phase-in-oil phase emulsion, or an aqueous phase-in-oil phase-in-aqueous phase emulsion. The agent may be released by one or more of a variety of mechanisms. For example, a water-soluble shale stabilizer could be delivered downhole in an aqueous phase-in-oil phase-in-aqueous phase multiple phase emulsion by injecting the multiple phase composition into a water-based drilling fluid, and then the suspension broken by rotary bit nozzles under high shear stress to release the shale stabilizer at the drilling zone.

Abstract: Pumpable multiple phase compositions for carrying agents and components downhole and controllably releasing them by breaking the suspensions are described. The multiple phase composition may have an external or third phase, which in turn has a first pumpable emulsion internally. The first pumpable emulsion has a second phase containing a first phase which bears the agent to be controllably released. The entire pumpable multiple phase composition may thus be an oil phase-in-aqueous phase-in-oil phase emulsion, or an aqueous phase-in-oil phase-in-aqueous phase emulsion. The agent may be released by one or more of a variety of mechanisms. For example, a water-soluble shale stabilizer could be delivered downhole in an aqueous phase-in-oil phase-in-aqueous phase multiple phase emulsion by injecting the multiple phase composition into a water-based drilling fluid, and then the suspension broken by rotary bit nozzles under high shear stress to release the shale stabilizer at the drilling zone.

Abstract: Pumpable multiple phase compositions for carrying agents and components downhole and controllably releasing them by breaking the suspensions are described. The multiple phase composition may have an external or third phase, which in turn has a first pumpable emulsion internally. The first pumpable emulsion has a second phase containing a first phase which bears the agent to be controllably released. The entire pumpable multiple phase composition may thus be an oil phase-in-aqueous phase-in-oil phase emulsion, or an aqueous phase-in-oil phase-in-aqueous phase emulsion. For example, a water-soluble shale stabilizer could be delivered downhole in an aqueous phase-in-oil phase-in-aqueous phase multiple phase emulsion by injecting the multiple phase composition into a water-based drilling fluid, and then the suspension broken by rotary bit nozzles under high shear stress to release the shale stabilizer at the drilling zone.

Abstract: The present invention provides a drilling system for drilling oilfield boreholes or wellbores utilizing a drill string having a drilling assembly conveyed downhole by a tubing (usually a drill pipe or coiled tubing). The drilling assembly includes a bottom hole assembly (BHA) and a drill bit. The bottom hole assembly preferably contains commonly used measurement-while-drilling sensors. The drill string also contains a variety of sensors for determining downhole various properties of the drilling fluid. Sensors are provided to determine density, viscosity, flow rate, clarity, compressibility, pressure and temperature of the drilling fluid at one or more downhole locations. Chemical detection sensors for detecting the presence of gas (methane) and H2S are disposed in the drilling assembly. Sensors for determining fluid density, viscosity, pH, solid content, fluid clarity, fluid compressibility, and a spectroscopy sensor are also disposed in the BHA.

Abstract: A drilling, drill-in, or completion fluid comprising water as a continuous phase, said continuous phase comprising a gas hydrate inhibiting amount of a blend comprising an ethylene glycol derivative and a propylene glycol derivative. The propylene glycol derivative is present in an amount effective to inhibit hydration of shale by the water base. The density of the fluid may be reduced by substituting the blend for salt, and by increasing the amount of propylene glycol derivative in the blend. The blend preferably should comprise at least about 10 vol % of the fluid, and a preferred ratio in the blend is about 35 vol % tripropylene glycol bottoms to about 65 vol % ethylene glycol.

Abstract: A fluid selected form the group consisting of a drilling, a drill-in, and a completion fluid, said fluid comprising a substantially linear heteropolyglycol in an amount effective to perform a function selected from the group consisting of polymer stabilization, shale stabilization, and a combination thereof. The fluid preferably comprises water as a continuous phase, and the heteropolyglycol preferably consists essentially of monomers selected from the group consisting of ethylene oxide and linear alpha-omega alkylene diols.

Abstract: A non polluting additive or spotting fluid which lubricates, releases and/or prevents differentially stuck drill strings and casings in the wellbore of a subterranean well is presented. This additive composition comprises a glycol or glycol ether derived from a long chain epoxide of greater than 3 carbon atoms (preferably greater than 10 carbon atoms); and preferably comprises the reaction product between 2-ethylhexanol and the epoxide of 1-hexadecene. The present invention enhances the lubricity of a drilling fluid to prevent drill string sticking and when utilized as a spotting agent reduces the time required to release a stuck pipe. This invention also helps reduce or prevent foaming. By eliminating the need for traditional oil-based components, the present invention is nontoxic to marine life, biodegradable, environmentally acceptable, easy to prepare, and capable of being disposed of at the drill site without costly disposal procedures.

Abstract: The present invention provides a method of preparing a fluid for use in drilling and completion operations comprising mixing a fluid comprising a salt of an alkaline earth metal with a nonionic colloid-forming material in an amount and under conditions sufficient to convert a majority of said nonionic colloid-forming material into water insoluble hydrated colloidal complexes comprising hydrated ions of said alkaline earth metal complexed with said nonionic colloid-forming material, said complexes being effective to improve a property of said fluid selected from the group consisting of rheology, fluid loss control, and a combination thereof.

Abstract: Brine-in-glycol emulsions are shown for use as well working fluids. The fluids have a glycol external phase and a brine internal phase. The separate phases are emulsified to create an emulsion and weighted with traditional weighting agents. The external phase is soluble or dispersible in sea water when diluted upon discharge.