A well fluid has a particle stabilized emulsion that has a first phase containing hydrocarbon fluid, a second phase containing brine, such as an aqueous alkali metal brine, and solid particles, wherein at least a portion of the solid particles are arranged at an interface between the first phase and the second phase to stabilize the emulsion. The well fluids can be used for drilling, completion, and/or workover fluids. A method of preparing the well fluid, which can be done in the absence of a surfactant, is also described.