×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

perforation

perforation

perforation

(OP)
my question is that if oil industry has to perforate a well (bullet perforating or jet perforating) so does the perforating gun passes form the tubing? the size of the tubing industry has maximum 4 inches so does it mean that perforating gun has the smaller diameter ? and after the perforation is done so doesnt the production starts as soon as we perforate ? and if production starts so how do we retrieve a gun?  

RE: perforation

Yep- you get a perforation gun that fits inside the production tubing.  There are lots of gun sizes- look at teh service company website to see them all.

If you have the tubing in place, you will also have the christmas tree in place, and the perforating will be done with pressure control equipment such as a lubricator, to allow you to remove the guns from the well without opening up the well.  You could, if you want, perforate overbalance, so that the well won't flow, but that upsets the production people.

Other methods of perforating include doing the perforations before you have run the tubing, so you can use big guns, but you have to kill the well to run the tubing, which might be bad for the reservoir; or on the end of the tubing string, called Tubing Conveyed Perforating.  This gives you big guns, no worries about killing the well afterwards and you can perforate underbalaance.  But the guns either stay there (which means you can't do any productiuon logging) or the guns are dropped (which means you have to drill a long sump for them to fall into).

A good textbook or trawl through the service company websites will give you a better discussion of the perforating options avaialble and the pros and cons of each one.

RE: perforation

I have a horizontal well with multi-stage perfs and multi-stage fracs.  Four stages have time-delayed perf guns.  Three guns were used in each of these stages.  The first gun perforated overbalanced.  And it is not evident on the 2nd and 3rd (time-delayed) if these were over or underbalanced.  We have pressure for the 2nd and 3rd guns on the first two stages, but not the last two stages.  Is there anyway of determining overbalance/underbalanced or can you direct me to info on time-delayed perf guns?

The pressure at which the guns were fired, is this pressure at surface or pressure at the guns (bottomhole pressure)?  

RE: perforation

I've never used time delayed guns, I'm afraid.  the service company that did the perforating job would be the best place to start of information about them and so on.

The issue of underbalance or overbalance assumes you know what the reservoir pressure is- if you know that accurately,and you have downhole pressure reading, knowing if you were over or underblance is easy.  Knowing the original reservoir pressure is usually the hard bit!  If you have surface pressure only, you can make a good estiamte on teh bottom hole pressure if you have a fluid composition and a tubing performance simulator like Prosper

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources