Low density oil-based wellbore fluids and methods thereof

A method, comprising:

• circulating a wellbore fluid in a wellbore, wherein
• the wellbore fluid comprises:
• an oleaginous continuous phase;
• a non-oleaginous discontinuous phase;
• an emulsifier stabilizing the non-oleaginous phase within the oleaginous phase;
• a low density material in an amount to result in a specific gravity of the wellbore fluid that is less than 0.83;
• wherein the low density material comprises glass microspheres, and
• at least one rheology modifier to suspend the low density material within the wellbore fluid, wherein the rheology modifier comprises a dimer poly-carboxylic C12 to C22 fatty acid, a trimer poly-carboxylic C12 to C22 fatty acid, a tetramer poly-carboxylic C12 to C22 fatty acid, or mixtures of these acids.