Drilling fluids having reduced sag potential and related methods

A method comprising:

• providing a drilling fluid that is free of organophilic clays and comprises:
• an invert emulsion, the invert emulsion comprising an oleaginous fluid continuous phase, an aqueous fluid internal phase, and a surfactant;
• barite particles having a size of at most about 45 microns;
• and
• a plurality of colloidal particles;
• wherein the drilling fluid has a density that changes by less than about 5% over at least about 62 hours of static aging;
• and
• drilling a wellbore in a subterranean formation using the drilling fluid, wherein the plurality of colloidal particles comprises fibrous colloidal particles and at least one other type of colloidal particle.

A method comprising:

• providing a drilling fluid that is free of organophilic clays and comprises:
• an invert emulsion, the invert emulsion comprising an oleaginous fluid continuous phase, an aqueous fluid internal phase, and a surfactant;
• barite particles having a size of at most about 45 microns;
• and
• a plurality of colloidal particles;
• wherein at least a portion of the plurality of the colloidal particles interact with the surfactant to form an associative supporting structure that inhibits sag of the barite particles;
• and
• drilling a wellbore in a subterranean formation using the drilling fluid, wherein the plurality of colloidal particles comprises fibrous colloidal particles and at least one other type of colloidal particle.