Some crude oils from eastern Venezuela, contain large amounts of high molecular weight components such as asphaltenes and waxes. Due to both the foaming characteristics of the crude oil and sluggish efficiency of the oil/gas separation process at the flow stations, both hydrocarbon contaminants asphaltene and wax are carried over to the gas gathering and transmission lines. These contaminants may deposit onto the inner wall of the pipelines producing some operational problems such as a decrease on the transmission capacity of the system and an increase of the cleaning frequency of gas pipelines. On the other hand, asphaltene and wax deposits may create a non-uniform barrier between the wall metal surface and the corrosive agents, interacting with corrosion inhibitors and reducing the corrosion rates. The scope of this paper is to describe the potential benefits of asphalthene and wax deposition as
corrosion inhibitors in gas pipelines, as well to present the experimental set up and some preliminary results from an ongoing research project,
Test conducted with a rotating cylinder electrode in gas sweetening conditions (temperature: 42 °C, PpCO2: saturated) and flow velocities up to 8 m/s showed a reduction of 50% on the corrosion rate of API- 5LB without inhibition and with a prefilmed wax treatment. For prefilmed asphaltene coupons at the same tests conditions, the reduction on corrosion rates were even higher with more than 70% of reduction in the range of 0 to 8 m/s. Key words: paraffin, asphaltene, RCE, weight loss