A fluid pressure transmission pill (FPTP) having an ultra-high viscosity for use in association with hydrocarbon drilling and exploration operations, particularly, managed pressure drilling (MPD) operations, is described. The ultra-high viscosity pill is a weighted pill composition that includes a hydrocarbon fluid, a thixotropic viscosifying agent, one or more activators, an emulsifier/wetting agent, a fluid loss control additive, and a weighting material. In accordance with selected aspects of the described fluid pressure transmission pill, the ratio of the amount of the thixotropic viscosifying agent to the activator is a ratio of about 7:1, and the weighting material is a barium-containing solid-phase material. Also described are methods of use of such FPTP products in subterranean operations, such as well killing operations during managed pressure drilling.

A fluid pressure transmission pill (FPTP) having an ultra-high viscosity for use in association with hydrocarbon drilling and exploration operations, particularly, managed pressure drilling (MPD) operations, is described. The ultra-high viscosity pill is a weighted pill composition that includes a hydrocarbon fluid, a thixotropic viscosifying agent, one or more activators, an emulsifier/wetting agent, a fluid loss control additive, and a weighting material. In accordance with selected aspects of the described fluid pressure transmission pill, the ratio of the amount of the thixotropic viscosifying agent to the activator is a ratio of about 7:1, and the weighting material is a barium-containing solid-phase material. Also described are methods of use of such FPTP products in subterranean operations, such as well killing operations during managed pressure drilling.

An invert oil-based mud (OBM) includes an oleaginous continuous phase, an aqueous internal phase, and an emulsifier that has two hydrophilic head groups and a hydrophobic tail group. A method of using an invert oil-based mud (OBM) in a wellbore is provided. The method includes introducing the invert OBM, which includes an oleaginous continuous phase, an aqueous internal phase, and an emulsifier with two hydrophilic head groups and a hydrophobic tail group into the wellbore. A method of preparing an invert oil-based mud (OBM) is also provided. The method includes mixing an emulsifier comprising two hydrophilic head groups and a hydrophobic tail group with an oleaginous phase and an aqueous phase.

An invert oil-based mud (OBM) includes an oleaginous continuous phase, an aqueous internal phase, and an emulsifier that has two hydrophilic head groups and a hydrophobic tail group. A method of using an invert oil-based mud (OBM) in a wellbore is provided. The method includes introducing the invert OBM, which includes an oleaginous continuous phase, an aqueous internal phase, and an emulsifier with two hydrophilic head groups and a hydrophobic tail group into the wellbore. A method of preparing an invert oil-based mud (OBM) is also provided. The method includes mixing an emulsifier comprising two hydrophilic head groups and a hydrophobic tail group with an oleaginous phase and an aqueous phase.

A treatment fluid comprises: a liquid fluorinated compound; and at least one additive, wherein the additive: (A) comprises carbon and at least one fluorine functional group; and (B) is soluble or dispersible in the liquid fluorinated compound. A method of treating a portion of a well comprises: forming the treatment fluid; and introducing the treatment fluid into the well.

A treatment fluid comprises: a liquid fluorinated compound; and at least one additive, wherein the additive: (A) comprises carbon and at least one fluorine functional group; and (B) is soluble or dispersible in the liquid fluorinated compound. A method of treating a portion of a well comprises: forming the treatment fluid; and introducing the treatment fluid into the well.

A hydrocarbon-based or ester-based drilling fluid or mud is described wherein the drilling fluid contains cesium phosphate. The hydrocarbon-based or ester-based drilling fluid or mud can have, for example, an external phase that contains hydrocarbon fluid and an internal phase that contains cesium phosphate. The hydrocarbon-based drilling fluid or mud can further contain at least one emulsifier or surfactant, and optionally other ingredients. The present invention can permit hydrocarbon-based drilling fluids to be essentially solids-free and may be used without corrosion and/or formation damage problems, for example, due to the use of the cesium phosphate in an internal phase of the hydrocarbon-based or ester-based drilling fluid. The present invention also relates to hydrocarbon-based or ester-based fluids for completion, workover, suspension and packer operations which contain cesium phosphate.

A hydrocarbon-based or ester-based drilling fluid or mud is described wherein the drilling fluid contains cesium phosphate. The hydrocarbon-based or ester-based drilling fluid or mud can have, for example, an external phase that contains hydrocarbon fluid and an internal phase that contains cesium phosphate. The hydrocarbon-based drilling fluid or mud can further contain at least one emulsifier or surfactant, and optionally other ingredients. The present invention can permit hydrocarbon-based drilling fluids to be essentially solids-free and may be used without corrosion and/or formation damage problems, for example, due to the use of the cesium phosphate in an internal phase of the hydrocarbon-based or ester-based drilling fluid. The present invention also relates to hydrocarbon-based or ester-based fluids for completion, workover, suspension and packer operations which contain cesium phosphate.

According to one or more embodiments of the present disclosure, a drilling fluid may comprise one or more deep eutectic solvents in an amount greater than or equal to 70 wt. % based on the total weight of the drilling fluid. Each deep eutectic solvent may comprise at least one hydrogen bond acceptor compound and at least one hydrogen bond donor compound. A molar ratio of the total moles of the hydrogen bond donor compounds to the total moles of the hydrogen bond acceptor compounds in each deep eutectic solvent may be from 0.1 to 1.0. The drilling fluid may have a density greater than or equal to 200 kg/m.sup.3. The drilling fluid may have a viscosity greater than or equal to 0.5 Pa.Math.s when measured at 25° C. Methods for drilling wells in subterranean formations using the drilling fluid are also disclosed.

According to one or more embodiments of the present disclosure, a drilling fluid may comprise one or more deep eutectic solvents in an amount greater than or equal to 70 wt. % based on the total weight of the drilling fluid. Each deep eutectic solvent may comprise at least one hydrogen bond acceptor compound and at least one hydrogen bond donor compound. A molar ratio of the total moles of the hydrogen bond donor compounds to the total moles of the hydrogen bond acceptor compounds in each deep eutectic solvent may be from 0.1 to 1.0. The drilling fluid may have a density greater than or equal to 200 kg/m.sup.3. The drilling fluid may have a viscosity greater than or equal to 0.5 Pa.Math.s when measured at 25° C. Methods for drilling wells in subterranean formations using the drilling fluid are also disclosed.