Pipeline Slug Mitigation
Pipeline Slug Mitigation
(OP)
I have a subsea gas well with reasonable amount of water content. Tieback distance to the host platform is about 5 miles, and it is an 8" pipeline. Initial calculations show that there'll be slugging. So my flow assurance engineer advises periodical pigging operation.
My question is, is there any other slug mitigation method as effective or even better than pigging? As much as possible I don't want to do subsea pigging, it is costly.
My question is, is there any other slug mitigation method as effective or even better than pigging? As much as possible I don't want to do subsea pigging, it is costly.





RE: Pipeline Slug Mitigation
You can try to keep flow velocities high enough such that liquids are sweept along and the slugging flow regime is avoided. Slugging is more prevelant at low velocities. The flow regeime also depends on ratio of gas to liquid flowrates and slope of the pipeline, so it still may not be possible to avoid, but you might be able to minimize it.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Pipeline Slug Mitigation
Put a HUGE slug catcher on shore.
RE: Pipeline Slug Mitigation
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Pipeline Slug Mitigation
RE: Pipeline Slug Mitigation
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Pipeline Slug Mitigation
I know of one water hose connected to a floating diaphragm inertia pump....Wave action pumps the water out of a collector.
RE: Pipeline Slug Mitigation
Best regards
Morten
RE: Pipeline Slug Mitigation
RE: Pipeline Slug Mitigation
Whether he needs a vessel "slug catcher" or an extended dead-end pipeline segment "drip", increase velocities or implement regular pigging depends on the ratio of the quantity of liquids produced to that of gas and the resultant flow regime. The problem with large vessels located upstream and close to the well, so that pigging the pipelines can be avoided, is that offshore space is very costly for placing large mostly empty vessels that can weigh a lot if they do happen to get full. Additionally, a means to empty the vessel to a boat must also be employed. Again not cheap. If velocities can't be keep high enough to continuously sweep the line, the standard solution is to pig the liquids all the way back to the beach in a 2-phase flow pipeline to where a large vessel can be economically positioned onshore.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Pipeline Slug Mitigation
Im not so sure (as i stated before) that the essence of the problems are "slugs".
The problem in this case _could_ be that on occation a fairly large water slug may come along.
But im not sure and the the original poster has not replied back since the first post.
Best regards
Morten
RE: Pipeline Slug Mitigation
I took the OP statement, "Initial calculations show that there'll be slugging." as the problem for which the solution recommended by the flow assurance engineer was pigging the line. Even high water to gas ratios are not a transport problem, if both water and gas can both be moved at uniform flowrates without liquid hold-up. Its the slugging that requires the extra handling equipment to accomodate it.
In any case, you are right in that we do seem to have much more interest in beating this apparent dead horse than the OP....
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Pipeline Slug Mitigation
This is common in offshore multiphase pipelines where the multiphase distance may be longer than on-shore and the pipeline normally follows the terrain.
Slugging in it self can be controlled to some degree by control of backpressure that is what multiphase simulation can help to investigate.
Since the original poster has not reverted i dont know if my suspicion is correct.
Best regards
Morten
RE: Pipeline Slug Mitigation
The pipeline gas to liquid ratios, velocities and pipeline profile can combine to make about 5 different flow conditions, sometimes in the same pipeline system. But sometimes you don't need a slug catcher, just a separator system, at least until you start making slugs somewhere.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Pipeline Slug Mitigation
RE: Pipeline Slug Mitigation
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com