Recycling Systems

Amine Reclamation
Heat Transfer Fluid
Glycol Purification

Results & Reports

Cost Analysis Overview
Fluid Dehydration
Glycol System Clean-up
Heat Transfer Review

PACER GLYCOL SYSTEM CLEAN-UP REPORT

Introduction

The plant mentioned in this report is located in southeastern New Mexico. This plant treats oil and natural gas that is gathered from the field. Some of the components in the treatment system include a membrane separator, cryogenic system, sour gas extraction system, Triethylene Glycol (TEG) gas dehydration system, compressors, etc. The TEG gas dehydration system cleanup consisted of four gas-liquid contactors, three-phase separator, glycol heat exchangers, regenerator, piping and any other component that comes into contact with TEG that circulates through the system. The gas dehydration system was no longer capable of producing pipeline specification natural gas (water content of 7 lb of H2O/MMcf). The 3500 gallons of TEG contained in the system was considered spent. The contaminated TEG caused many problems within the system including excessive TEG losses, the reboiler was unable to achieve sufficient temperature to regenerate TEG, excessive fuel gas consumption, inefficient particulate filtration, high dew points, downstream plant operations were malfunctioning, and continual plant shut downs were caused by shut down alarms being activated. As a result, this plant was experiencing excessive labor problems.

Conventional cleaning of the dehydration system was unattractive to this plant due to the shut down of the system, disposal of waste product, excessive cost, and questionable effectiveness. Therefore, cleanup was performed by Cimarron Gas Processing using the PACER.

Job Summary

1. Analysis shows that the TEG contained in the system was extremely contaminated. The TEG weight percentage was at 72.40%, water weight percentage of 2.5%, pH of 10.8, chlorides showed 620 ppm, suspended solids or particulate contamination 1165 ppm, and hydrocarbons at 0.18wt%. This analysis was determined from samples taken before cleaning the system. TEG samples were taken after cleaning for 30 days. This analysis showed that the TEG weight percentage is at 99%, water weight percentage 1.38%, pH of 10, chlorides showed 12.8 ppm, suspended solids or particulate contamination 270 ppm and hydrocarbons at <0.05wt%.
2. Reboiler fuel gas consumption upon arrival is shown on an attached chart. The fuel gas consumption was calculated from a pressure gauge on the burner fuel gas line. The burner ran constantly for 24 hours a day at a gauge reading of 24 psig. The gas flow was calculated using the Weymouth formula and chart located in GPSA, Vol. II, page 17-8. From the data given the gas flow rate to the burner was 22 mcf/day. Using a gas cost of $2.25/mcf this shows a $1485/month fuel cost to the burner. With the burner running constantly the reboiler temperature obtained was only 300°F. After the system was clean, the burner was able to cycle on and off periodically giving a run time of 12 hours a day at a gauge reading of 12 psig. From the data given, the gas flow rate to the burner was 8mcf/day. Using the same gas cost this shows a $540/month fuel cost to the burner. This gives the plant a monthly operational cost savings of $945. The reboiler now maintains 360°F with reduced fuel consumption.
3. Particulate filtration of the TEG was accomplished with a 20µ bag filter and 10µ cartridge filters. The cartridge filters and bag filter were being saturated daily. After cleaning for 25 days, filter changing frequency was reduced from daily to weekly.
4. The dehydration system was drying the gas to a water content of 40 lb of H2O/MMcf at the outlet of the contaminated contactor before cleaning. The water content continued to drop during the cleaning process. The dehydration system is now able to achieve a gas with a water content of 6 lb of H2O/MMcf.
5. During the cleaning process the plant experienced two upsets with the Amine system upstream of the dehydration system. These upsets recontaminated the TEG and as a result, altered the end statistics for this job.

CUSTOMER ANALYSIS OF COST SAVINGS