Pipe Slugging - Audit

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Pipe slugging, release 1, issued 29 Jan 2009. AUDIT version.

The current release of this worksheet exists in different versions. They are identical apart from the way they are formatted. The Work version hides intermediate calculations and allows the user to see the results just below the inputs. The Audit version displays all intermediate calculations and results to allow auditing.

User input

 

10

 

psi/ftSG or kg/lppgkPa/mlb/ft3lb/bbl

Active mudweight. Jmudsg =

 

15

 

psi/ftSG or kg/lppgkPa/mlb/ft3lb/bbl

Slug mudweight. Jslugsg =

 

10

 

lm3bblft3

Slug volume. Vslug =

 

4.276

 

inmm

Drillpipe ID. L_ddp =

 

1000

 

lm3bblft3

Volume of active system (optional). Vmudact =

  

Click here when any values are modified to update the result.

Calculations

Figure out the length of the slug when displaced into the drillpipe.

What length of active mud gives the same hydrostatic as the slug?

The difference between these two lengths is the length of dry pipe at the top of the string.

U tubing volume equals the volume of air at the top of the pipe.

The total flow back into the trip tank = slug volume + volume of dry pipe.

The mudweight will increase once the slug is fully mixed in to the mud system.

Results

Length of dry pipe after full u-tubing

Volume increase u-tubing only

Total volume increase (slug vol + utubing)

Active system density after slug mixed

Worksheet references

Version 1 of this worksheet released on 29 January 2009 by Steve Devereux CEng after a request by Mr Randy Davis of NRG Ltd.

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