A hydraulic cementing composition and a method of making the same is disclosed. The composition is useful to form a sheath of hardened cement in the annular space between a well pipe disposed in a well bore and the walls of the well bore. The cementing composition is a mixture of dry ingredients comprising hydraulic cement and an additive to control the loss of fluid from an aqueous slurry containing the cementing composition. The fluid loss additive and a method of making the same is disclosed. The fluid loss additive is the reaction product of three chemical compounds each having an ethylene backbone and functional groups selected from carboxylates, hydrogen, anhydrides and combinations thereof.