Abstract
Crude oil and natural gas with condensate production can contain varying ratios of acid gases which are extremely corrosive to metal surfaces. Because of its corrosiveness, sour production may require specialized production equipment such as Inconel metallurgy to mitigate the severe environment; hence the control of sour corrosion is a major concern in the oil and gas industry today. Currently, most sour corrosion inhibitors are based on alkyl pyridine (AP) chemistries and typical treatment rates for critical sour environments range from 200-1000 ppm based on brine production.
The objective of this work is to develop an alternative sour corrosion inhibitor to replace alkyl pyridine formulations. This paper investigates the effect of different operating parameters such as temperature (300C, 500C, 800C and 1200C), salinity (low, medium and high), H2S composition (10%, 20%, 35%), CO2 composition (4% and 10%) and brine to oil ratio (90:10, 70:30, and 50:50) on the performance of the new inhibitor chemistry.
In this paper a non-alkyl pyridine corrosion inhibitor (NAP CI) formulation was developed to prevent corrosion in critical sour systems. In the lab testing conditions used the unmitigated corrosion rates ranged from 30-50 mpy with varying degrees of pitting. The non-alkyl pyridine chemistry treatment ranges of 200-300 ppm demonstrate an excellent reduction in both the synthetic brine and gas phase corrosion rates. This was supported by corrosion rates of less than 3 mpy and no observed pits.
