Centrifugal Compressor life expectancy? 1

[bkarim55]

Dear All ;

Gas and Steam turbines designed to Oil & Gas Applications are commonly used to drive CCs (Centrifugal Compressors). My question is about life expectancy of these CCs. I would like to know your experience and how much time do you take to overhaul your CCs ? and what is the real MTBM (Mean Time Between Maintenance) of your compressors?

Thanks in advance & Regards
Karim

 

[JJPellin]

Your questions are much too general to get meaningful answers. It is like asking “How should I maintain my centrifugal compressor?”. But, I will try anyway. A well designed and maintained compressor should last for 100 years. We are currently overhauling our oldest machine which has been in continuous operation since 1955. I am sure it will still be running in another 20 years.

Our compressors are expected to run without failure from turnaround to turnaround (typically 4 to 6 years). And they almost always meet that expectation. When we perform a full overhaul, it could take from 2 weeks to 4 weeks. The machine should be designed so that an overhaul is possible within the expected unit turnaround duration.


Johnny Pellin

 

[bkarim55]

Dear Johnny;
Thank you so much for sharing your knowledge and your experience…

The centrifugal compressors I’m talking about are used to compress Natural Gas. Some of them are installed on reinjection station to pressurize the field and enhance oil recovery and some others are used on pipelines.
Gas turbines are used to drive those CCs. And every 48.000 hours (about 5 years) we perform both Major Inspection of the turbine and we also overhaul the compressors.

Our Compressors are good maintained and I’m suspecting troubles are upstream and probably liquid (probably water) arrives (with natural gas) to the compressor components and damages them… What do you think?

About your oldest compressor how many turnarounds do you make before to perform major overhaul?

Regards
Karim

 

[JJPellin]

The runs between overhaul depend on the service. From worst to best, our expectations would be as follows:

• Coker Wet Gas – Every TA, not to exceed 5 years.
• FCC Off Gas – Every second TA, not to exceed 10 years.
• Hydrotreater Hydrogen Recycle – Every second TA, not to exceed 12 years.
• Alky Refrigeration and Air – Every forth TA, not to exceed 20 years.

If your service is wet, you will probably be limited to running 5 years to the gas turbine major overhaul.


Johnny Pellin

 

[awhicker84]

What problem are you having?

If liquid is entering the CC, blade erosion will occur and shorten the life of the impeller.