Abstract
The presence of elemental sulfur and polysulfide severely aggravates the corrosion in sour gas systems. Application of sulfur solvent and corrosion inhibitor aims to mitigate corrosion. However, in some cases, very sticky solid deposits in pipeline are found, which is believed to be the mixture of elemental sulfur and extracted corrosion inhibitor bases. How to keep the high efficiency of chemicals in field condition and avoid the sludge formation is quite challenging.
Combined products of sulfur solvent and corrosion inhibitor are developed in this work, which can be mainly used in pipeline batch program or applied by continuous injection in some situations (dry gas with turbulent flow). The evaluation of products shows that the products are tolerant to hydrocarbon dilution and has a good sulfur uptake even at low temperatures. The stability of the product upon the hydrocarbon dilution reduces the chances of active ingredient drop-out and helps the elimination of sludge formation.
Autoclave tests has been conducted done for batch application using brine and the polysulfide solution under sour conditions, showing that the products provide more than 90% corrosion protection in polysulfide solution. After dissolving elemental sulfur, the products also give excellent corrosion mitigation.
