Publications

Sumatra Operations produce more than 35 MMSCFD gas which is purified at each field Gas Plant (GP) and sent to power generation systems. We previously encountered operational and maintenance problems related to high heavy hydrocarbon (HHC) and gas impurities such as H2O, CO2, and H2S which reduce pipeline integrity, reduce equipment reliability, and increase gas imbalance. After troubleshooting, the project team selected alternatives for gas quality improvement by improving Triethyleneglycol (TEG) dehydration performance, utilizing the existing chemical service contract, and improving existing gas processing. H2O content has been reduced from 50 to 15 lbs/MMscf, meeting specifications. This was achieved by adjusting operational parameters to optimize the separation process and perfecting the glycol reconcentration system to maintain TEG quality. Lab results were used as main reference of a glycol care program. This program improved dehydration unit (DU) performance by thorough glycol property interpretation to decide the required actions on DU equipment such as: installed auto-drain on the glycol flash tank, replacement of solid and carbon filter cartridges based on performance, and repaired heat exchanger. H2S content has been reduced from 300 ppm to 10 ppm, meeting specifications, by isolating sulfate reducing bacteria (SRB) source as one of H2S producers and injecting triazine based scavenger reacting with H2S and forming nonhazardous, low toxicity water soluble liquid which is also excellent as a corrosion inhibitor. HHC has been reduced from 35% to less than 15%, meeting specifications, by perfecting gas – liquid separation process using additional separator, increased separator performance, and lowering gas temperature using a mechanical refrigeration system. All problems of pipeline integrity, equipment reliability, and gas imbalance related to gas quality have successfully been reduced. This project potentially saved $9 Million of operational expense within one year with the total project costing less than $0.5 Million.