Pipeline Pig Tracking

[jonjose123]

Hello Members,

Currently, there was a observation/clarification from operations stating that 20" buried Gas pipeline crosses many other pipelines and hence it will be difficult for pig tracking.
Project is under finalisation stage in terms of routing and operations and stating this comment. We have pigging procedure in place for pig tracking and pig stuck scenarios.

How pig tracking will affect with buried pipeline having large number of crossings. Is there any relation between the two?

 

[LittleInch]

How are you tracking the pig?

Most times you can only really do this by applying sensors to the pipeline at certain intervals with the pipe exposed / above ground although some do work for buried lines.

But normally this is only a spot connection every few kms.

Crossing lines will be deeper than normal plus the other pipe might interfere with the magnetic signal or the radio sender.

Your operations department doesn't sound like they really know what they are talking about. No one I know tracks pigs continuously from one end to the other. Do you know why anyone is that concerned about stuck pigs?

There's mnore to this than you're saying, but if you don't tell us the full story we can't respond properly.

 

[jonjose123]

How are you tracking the pig?

Most times you can only really do this by applying sensors to the pipeline at certain intervals with the pipe exposed / above ground although some do work for buried lines.

But normally this is only a spot connection every few kms.

Crossing lines will be deeper than normal plus the other pipe might interfere with the magnetic signal or the radio sender.

Your operations department doesn't sound like they really know what they are talking about. No one I know tracks pigs continuously from one end to the other. Do you know why anyone is that concerned about stuck pigs?

There's mnore to this than you're saying, but if you don't tell us the full story we can't respond properly.

Hi LittleInch,

Thanks for the response.

For intelligent pigs its being tracked with MFL technique.

Yes, As you pointed out, our pipeline crosses existing pipeline corridor at a depth of not less than 2 m from grade level and 600 mm min beneath existing pipes. Also you rightly pointed out, Operations are more concerned about tracking rather than stuck pig scenario.


Story is, Engineering have designed pipeline and route finalised and under detailed engineering stage finalisation., now operation came up with an issue about this where during FEED stage did not had any problem.

Now we are struggling to convince them as they want to change the route with minimum crossing. Which is not a realstic thing as all corridor has been fixed and got authorities approval.

 

[LittleInch]

I said, Operations are just creating issues from nothing.

The vast majority of people I know only track pigs at interval of several km or where it is possible. The number of crossings are irrelevant IMHO.

My guess is that one person in operations had a problem a long time ago, or heard of a friend of his previous boss had a problem 35 years ago..... whatever, there is zero need to do a re-route or re-design. In think you just need to go back up the tree and note that there were no objections in FEED, route is approved, etc etc. If Operations insist on a re-route and they can object to the approval if not, then the impact will be $$$ and months on the schedule and leave it to the respective managers to argue it out with the people paying the money and wanting the pipeline build sooner rather than 6 months later.

 

[jonjose123]

I said, Operations are just creating issues from nothing.

The vast majority of people I know only track pigs at interval of several km or where it is possible. The number of crossings are irrelevant IMHO.

My guess is that one person in operations had a problem a long time ago, or heard of a friend of his previous boss had a problem 35 years ago..... whatever, there is zero need to do a re-route or re-design. In think you just need to go back up the tree and note that there were no objections in FEED, route is approved, etc etc. If Operations insist on a re-route and they can object to the approval if not, then the impact will be $$$ and months on the schedule and leave it to the respective managers to argue it out with the people paying the money and wanting the pipeline build sooner rather than 6 months later.

Thanks a Lot LittleInch.. You are absolutely correct. The operations team are apparently well known for creating hurdles where there is no issues at all..

 

[Krausen]

Not an issue. Having pig sensors/"pig sigs" installed at strategic locations in your pipeline system (typically aboveground at all pig launchers/receivers) will help too. I've always used the pig sigs from TD Williamson.

 

[georgeverghese]

Low points in pipelines(caused by ducking down beneath other pipelines) may be a problem for Operations for liquids handling at downstream destination for gas that is operating at or below dewpoint conditions. They will have to pig more often to keep liquid inventory in this pipeline low so as not to overwhelm downstream liquids handling facilities.

 

[LittleInch]

General slope or terrain has a much bigger impact than the few metres of pipe which is below the other pipes.

The operations dept are talking rubbish.