Abstract: Emulsions usable within a wellbore as drilling fluids can be prepared by adding an internal phase to an external phase to form an emulsion base, and adding solid organophilizated mineral structures, a matrix stabilizing agent, a weighting agent, and a secondary stabilizer to the emulsion base. The solid organophilizated mineral structures stabilize the emulsion base and affect the rheology thereof, and the matrix stabilizing agent and the secondary stabilizer can retain the stability and viscosity of the emulsion base in the presence of hydrophilic solids. In addition to use as a wellbore fluid independently, usable emulsions can be compatible with and combined with traditional emulsions to form a mixture usable within a wellbore a drilling fluid.

Abstract: Emulsions usable within a wellbore as drilling fluids can be prepared by providing an emulsion base that includes a crude biodiesel product, and adding an emulsifying subsystem to the emulsion base. Solid particles in the emulsifying subsystem migrate to interfaces between continuous and discontinuous components in the emulsion base to define phases of the emulsion. A weighting agent can be added, as needed, to provide the emulsion with a suitable mud weight for use in a particular wellbore. Usable crude biodiesel products can include the unmodified product of a transesterification reaction, that include a continuous ester phase and a discontinuous alcohol phase without requiring separation or modification. Usable emulsifying subsystems can be prepared in situ. Use of esters, clays, and/or alcohols can enable reduction or elimination of water, brine, and petrochemicals in the emulsions.