Abstract: The present application, at least in part, is directed to a method of providing a substantially constant rheological profile of an oil-based drilling fluid over a temperature range of about 120° F. to about 40° F. In some embodiments, the method comprises adding a drilling fluid additive to the drilling fluid, wherein the drilling fluid additive consists essentially of a polyamide and a set of at least one or more mono-carboxyl units. The polyamide has (a) repeat units of (i) a poly-carboxyl unit with at least two carboxylic moieties; and (ii) a polyamine unit having an amine functionality of two or more and the one or more mono-carboxyl units being positioned on the polyamide at a position selected from the group consisting of: an end position, a pendant position and combinations thereof.