I'm pleased to post this on behalf of a regulator in Europe. Due to the need for Regulators to avoid conflict of interest ("making recommended course or action"), he would rather remain anonymous.
"With reference to the question raised the only immediate discussion point I can see is the gate valve design. Is the gate a ‘split gate’ design or a ‘solid gate’ design?
Pressure testing a ‘solid gate’ gate valve in the wrong direction is not ideal to confirm its integrity. Pressure testing a ‘split gate’ gate valve in the wrong direction is slightly better due to the design of the gate valve but it is not ideal.
It would be useful to develop a working relationship with their local Furmanite International (aka Team Inc) representative for assistance.
It might also be useful to read through the Oil & Gas UK ‘Well Life Cycle Integrity Guidelines (Issue 3 dated Mar-2016)’ for further information on the verification of well barriers in difficult circumstances."
I hope this helps
with Well Examiner comments, of course: no way can disassemble tree
without replacement parts, and to wait for snubbing unit is sensible course,
First off what is the rush,,, have a disaster? I would leave everything as is until all personnel and equipment is available at or near the well site.
As Pete Aird pointed out, hire an accredited expert. If they are planning for snubbing ops, I am sure the snubbing operator could provide such a person and also back up data from similar operations.
I do not understand why at this point all of a sudden they have to take the “the wing valve off the tree to rotate an instrument block”, its already noted that the well has been left alone for a year?
As Bill Abel noted, they can more or less do anything they want once they have the snubbing unit BOPs nippled up on the well
My recommendation would be get all the personnel and equipment available, sort out the programme, get professional help, do the what if’s until then don’t poke the bear."
You are testing gates against the direction of flow and this does indeed not constitute a valid barrier.
Norsok D10 rev 4 states “Tree valves of floating gate design shall be tested in the direction of flow from reservoir. The test of master valves may be omitted if the shut-in pressure is insufficient to give a conclusive test. This is provided the wing valves are tested in the flow direction by pressuring up the X-mas tree cross.”Do not fully understand why there is a need to install an instrument block on the tree. Recommendation would be not to compromise the tree integrity.
If the tree is not leaking now, leave it alone!!
Rig up on the top of the tree with a BOP and install any required instrumentation on the BOP. The BOP can be stump tested and that would only require the upper tree cap connection to be tested once the BOP is installed and that can be done against the swab valve leaving both the LMV and UMV closed. Ensure that the snubbing BOP has a flow line with chokes installed that allows bleeding off of any gas to a separator or MGS.
If there is a space issues rig up using additional risers. Once the BOP is rigged up and tested you can then open the tree valves and get started.