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Shearing expandable liner and inner running stirng.
08 October 2014
Has anyone any knowledge of tests conducted or data to support that a subsea bop shear ram will and can shear an expandable liner and the inner running string.

We know it should but is there any verificaiton to this effect.


2 answer(s)
Consultant [retired Shell staff]
Total Posts: 249
Join Date: 02/09/05
The challenge is both geometric and physical.
1. The flattened dimension of the expandable liner MUST BE smaller than the width of the shear blade. As an example, a 13 5/8" Cameron BOP shear ram (blade width 11") can only cut up to 7" expanded liner; similarly, the 18 3/4" BOP (14" blade) is limited to items below 8.9".
2. Assuming that the expanded liner flattened dimension is under the shear blade width, then is a matter of enough operating pressure, often under 3,000 psi.
3. My guess is that you may need a "Super shear ram" i.e. a non-sealing ram to have a blade width as large as the BOP bore (no need for the room for the side seal pack).
Completions Engineer
Total Posts: 7
Join Date: 09/11/06
Peter, sorry, cannot answer your query however we (at Nexen UK)are looking to run expandable liners off the back of a Snubbing unit and are curious as to your application. It looks like you're on a semi and running open hole? We have a small team working on our application and would be happy to enter into dialogue for mutual learnings?  If you want to tap into our knowledge base, you or your engineers can contact, he may be able to assist you.  Regards
Posted by

Peter Aird

Drilling Specialist/Well Engineer/Training Consultant

Kingdom Drilling

Total Posts: 362
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