Anyone any experience of installing a Velocity String in a Subsea well?

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If anyone has ever done a Velocity String in a Subsea well, would be great to hear about the issues and pitfalls you have experienced. What equipment did you use, where did you hang off the string and with what tools? If below the SCSSV, what did you run, if anything, above the SCSSV or did your modelling suggest the velocity was higher above the SCSSV so no Velocity String required there?
asked May 4, 2017 in COIN by Steve Hall (120 points)

3 Answers

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Steve,

Response from Fraser Martin in Chevron Aberdeen:

Have a very bad experience of dropping a 2 7/8” velocity string into a well due to a coil runaway. It was a platform well though so probably not of interest.....

·  What equipment did you use? A:  2 7/8” coil tubing

·  Where did you hang off the string and with what tools? A:  Hung off just below the SCSSV in a nipple profile.

·  If below the SCSSV, what did you run, if anything, above the SCSSV or did your modelling suggest the velocity was higher above the SCSSV so no Velocity String required there?   A:  Nothing run above the SCSSV. There was minimal benefit for the relatively shallow 850ft of 5 ½” tubing.  We looked at running a second short string above the SCSSV but decided against it as it complicated matters too much.

Regards

Fraser Martin, Chevron NOJV Drilling & Completions Engineer

answered May 4, 2017 by Fiona Curley (1,480 points)
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Steve,  

Another response for you, this time from Chip Claiborne of Chevron in the US:

It’s hard to picture a subsea well would be economic with that type of restriction d/h in today’s price environment.

Much work however has been done in land applications but obviously many differences when moving this to SS application..

Chip Claiborne, Completions Design & Project Support Team Leader, Chevron
answered May 4, 2017 by Fiona Curley (1,480 points)
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Steve,

Response from Alex Crabtree of Hess in the US:

Personally I am not aware of any velocity string installations in subsea wells.  There are numerous installations that have been done offshore but they were all dry-tree.  Most that I am familiar with hung the string off below the SSSV with either a packer or from a hanger in an existing profile.  The velocity in the last top part of the completion was still sufficient to carry the water.  These were not deep water so the SSSV’s were set only a few 100’s of feet below the mudline, not 1000’s.  An issue that was always upper most in the offshore installations was how can the velocity string be retrieved at the end of the well’s life

I guess the first question might be what type of tubing string is it likely to be – jointed, coiled tubing, steel or composite?  This might limit installation methodologies and cost mitigation.

 

Alex Crabtree, Senior Advisor, Technology and Excellence Group, Hess Corporation
answered May 4, 2017 by Fiona Curley (1,480 points)
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