Revamped corrosion program cuts costs and downtime in coalbed methane field
An operator in a coalbed methane field began to see very aggressive CO2 corrosion in the tubing string of a well and failure rates as high as 1.7 every year. Each failure was costing anywhere between $25-30K USD. ChampionX was asked to look at the situation and recommend a program that would help alleviate the problem.
CHALLENGE
A pipeline operator in a coalbed methane field in Utah had a well that was producing between 300 to 400 mcfd and 50 barrels of water with a CO2 content around 12%. In the early years of production, even though this well had a high CO2 content, there were no signs of corrosion. Over the years, the operator began to see very aggressive CO2 corrosion in the tubing string and failure rates as high as 1.7 every year costing anywhere between $25-30K USD per failure. ChampionX was asked to look at the situation and recommend a program that would help alleviate the problem.
SOLUTION
ChampionX studied the situation in conjunction with the operator and learned that much of the corrosion was due to high fluid levels in the casing. Because the pumps were producing at such a high rate, CO2 saturated condensate were being pumped out of the production tubing creating corrosion in the tubing string. ChampionX decided to implement an aggressive treating program based on field experience and monitoring results. At the same time, the operator agreed to reduce production.
Batch treating with CORR12479A was based on water production: • >70 bwpd = 30 ppm with 12 gallons max per treatment • 51 – 70 bwpd = Every two months • 31 – 50 bwpd = Every four months • 1 – 30 bwpd = Every six months Continuous injection with CORR10234A for wells with greater than 70 bwpd but producing less than 400 mcfd. These nine wells were treated with 30 ppm based on water production.
RESULT
Results were seen almost instantaneously as the failure rate dropped to 0.27. The cost savings from failure reduction were close to $500K USD.