A method of sealing a formation that includes drilling a wellbore through the formation while pumping a non-aqueous based wellbore fluid comprising a first sealing component into the wellbore, wherein the non-aqueous based wellbore fluid filters into the formation as a filtrate and substantially thickens is disclosed. The substantially thickening may result from adding a second sealing component to the wellbore fluid, whereby the first sealing component initiates a reaction of the second sealing component.