Abstract: The present application pertains to an imaging fluid and a method for subsurface imaging, such as that of electromagnetic imaging, comprising introducing said imaging fluid into a borehole. The imaging fluid comprises a plant-based oil, a drilling fluid weighting agent and a saturated fatty acid, and has the properties of a dielectric permittivity of from 2 to 5 and a density greater than water. In one example, the imaging fluid is comprised of: canola oil or castor oil 40-75%, stearic acid 1-10%, and barium sulfate 15-45%, all percentages are weight by total weight of the imaging fluid.