Rheology modifiers comprising dicarboxylic acid, additives and oil-based drilling fluids comprising said rheology modifiers, as well as methods and uses thereof are provided. The rheology modifier dicarboxylic acid may comprise, for example, dodecanedioic acid. Rheology modifiers as described herein may be used, for example, to increase low shear end viscosity of an oil-based drilling fluid.

Rheology modifiers comprising dicarboxylic acid, additives and oil-based drilling fluids comprising said rheology modifiers, as well as methods and uses thereof are provided. The rheology modifier dicarboxylic acid may comprise, for example, dodecanedioic acid. Rheology modifiers as described herein may be used, for example, to increase low shear end viscosity of an oil-based drilling fluid.

Disclosed is a method for producing a drilling fluid, comprising: a) preparing mixed fatty acids from a biomass-derived oil, b) subjecting the mixed fatty acids of step a) to an estolide reaction with a light acid to give an estolide, and c) esterifying the estolide of step b) with an alcohol to obtain the drilling fluid.

Disclosed is a method for producing a drilling fluid, comprising: a) preparing mixed fatty acids from a biomass-derived oil, b) subjecting the mixed fatty acids of step a) to an estolide reaction with a light acid to give an estolide, and c) esterifying the estolide of step b) with an alcohol to obtain the drilling fluid.

The present invention relates to a drilling composition comprising an organic phase having at least one linear or branched, cyclic or non-cyclic, saturated hydrocarbon, at least one ester, water or aqueous phase, and at least one additive.

The present invention additionally relates to the use and preparation of the drilling composition, to a drilling system, to a process for making a borehole, to a process for conveying cuttings, to a process for treating a drill head, and to a process for production of oil and/or gas.

A waste vegetable-oil based emulsifier for use as drilling mud primary emulsifier is described. A first emulsifier is prepared from an alkyl ester of waste vegetable oil. The waste vegetable oil is vegetable oil which has been used for a process prior to preparing the first emulsifier. A quantity of the first emulsifier is added to an oil-based drilling fluid. A quantity of an activating agent is added to the oil-based drilling fluid. The activating agent is configured to activate the emulsifier to stabilize an emulsion. A quantity of viscosifier is added to the oil-based drilling fluid. A quantity of a second emulsifier is added to the oil-based drilling fluid. A quantity of weigh-up material is added to the oil-based drilling fluid. The resulting oil-based drilling fluid is used in a wellbore drilling operation to drill a wellbore in a subterranean zone.

A waste vegetable-oil based emulsifier for use as drilling mud primary emulsifier is described. A first emulsifier is prepared from an alkyl ester of waste vegetable oil. The waste vegetable oil is vegetable oil which has been used for a process prior to preparing the first emulsifier. A quantity of the first emulsifier is added to an oil-based drilling fluid. A quantity of an activating agent is added to the oil-based drilling fluid. The activating agent is configured to activate the emulsifier to stabilize an emulsion. A quantity of viscosifier is added to the oil-based drilling fluid. A quantity of a second emulsifier is added to the oil-based drilling fluid. A quantity of weigh-up material is added to the oil-based drilling fluid. The resulting oil-based drilling fluid is used in a wellbore drilling operation to drill a wellbore in a subterranean zone.

Alkyl ester spotting fluid compositions and processes for freeing differentially stuck pipe are provided. An alkyl ester spotting fluid composition includes an invert emulsion having an alkyl ester as the external phase and water as the internal phase. In some embodiments, the alkyl ester spotting fluid composition may include the alkyl ester invert emulsion and an emulsifier. The alkyl ester spotting fluid composition may be introduced downhole in the vicinity of a portion of a differentially stuck pipe such that the spotting fluid composition contacts the mudcake and frees the differentially stuck pipe.

A process for producing a base oil composition particularly adapted for use in oil-base drilling mud compositions. The process includes contacting drilling waste containing an oil-base mud phase with a solvent to produce a mixture of liquids and solids, separating the two phases, partially evaporating the liquids phase to produce an oil base composition substantially lacking low molecular weight carbon chain compounds and also lacking significant concentrations of benzene, toluene, xylene, and/or ethyl benzene, and having increased closed-cup flashpoint when compared to the oil-base mud phase in the drilling waste. The resulting base oil has enhanced health and safety characteristics for workers interacting with and otherwise exposed to the oil base composition during transporting, conditioning or using such compositions. The base oil produced and drilling methods using the recovered and recycled mud are also described.

A process for producing a base oil composition particularly adapted for use in oil-base drilling mud compositions. The process includes contacting drilling waste containing an oil-base mud phase with a solvent to produce a mixture of liquids and solids, separating the two phases, partially evaporating the liquids phase to produce an oil base composition substantially lacking low molecular weight carbon chain compounds and also lacking significant concentrations of benzene, toluene, xylene, and/or ethyl benzene, and having increased closed-cup flashpoint when compared to the oil-base mud phase in the drilling waste. The resulting base oil has enhanced health and safety characteristics for workers interacting with and otherwise exposed to the oil base composition during transporting, conditioning or using such compositions. The base oil produced and drilling methods using the recovered and recycled mud are also described.