Retention of Sand Particles Upstream of Reciprocating Compressor

[EmmanuelTop]

Good day to everybody,

Please see attached the granulometry analysis of sand particles from a gas production system. As you can see, more than 25% of the particles is smaller than 40 micrometer (threshold for visibility with a naked eye).

I have a discussion with the wellhead compressor vendor, regarding the required efficiency of the sand removal system upstream of the field compressors (gas engine driven, piston type), and it seems like we cannot reach an agreement with regards to the practical limits of size of sand particles that should be retained by the existing separator/strainer system upstream.

The issue is that I do not want to use a set of cartridge filters in gas field production environment, which is recommended by the vendor. This thing will get clogged on a daily basis. What we can consider logical is adding a fine mesh strainer (mesh 300) in series with the existing system, to keep the paricles larger than 50 micrometer away from the compressor. Production stream consists of Methane-rich gas, produced water, and sand.

Based on your experience, what is the best way to proceed forward?

http://antwrp.gsfc.nasa.gov/apod/astropix.html

 

[MikeHalloran]

>>> ... I do not want to ... <<<

If you don't install filters, does that affect the compressor warranty?
How about making the cartridges easy to clean and re-use, like K&N filters, and providing a wash/rinse station onsite?

Is it cheaper to replace cartridges every day, or compressors every (N) days?
Can the vendor give you a good estimate of the value of (N)?

Can you use centrifugal separators upstream of the filters, or some other kind of prefilters to extend the cartridge life?








Mike Halloran
Pembroke Pines, FL, USA

 

[gr2vessels]

Emmanuel, you seem to have a real problem, as highlighted by Mike above.
Would the compressor be happy to swallow 1/3 of the sand load? This question should be answered by the manufacturer who provides the warranty, has nothing to do with your preferences. The manufacturer should also specify the maximum load of dust that can be handled by the compressor without extensive damage.
However, you can size the strainer to be cleaned once a week or a month, entirely up to you. A good centrifugal separator will never clog-up and can be closely monitored for optimal operation, particularly if you have liquid load also. Less than 1 micron is the begining of the name filtration, the rest is straining.
I would go with Mike's advice to use an upstream separator to remove 99.5% of liquid, coarse and fines, then use an oversized cartridge filter guaranteed for 7/14/28 days operation, perhaps duplex with a flow switch for maintenance.