Corrosion inhibitors continue to play a vital role in controlling internal corrosion associated with sour oil and gas production. From the environmental point of view, research efforts are necessary to develop corrosion inhibitor products which on one hand are effective in corrosion
preventing and on the other hand are more acceptable to the environment than conventional types of inhibitor compounds. Performance screening of derivatives of polysuccinimide and lactobionic acid for carbon steel inhibition has been carried out under severe sour gas conditions in brine and brine /hydrocarbon mixtures at 90 to 130 °C with the rotated cage method. The resuks are compared with the performance of a well established conventional sour gas inhibitor. Keywords: Corrosion, inhibitors, polyaspartic, polysuccinimide, environmentally friendly, hydrogen sulphide, sour service, evaluation.