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MS700 stuck wearbushing
27 June 2014

Hi All, we are conducting a subsea well suspension and are having some difficulty recovering the 10¾" wearbushing. We have been up to some significant overpulls with the GE wearbushing recovery tool (up to 400 k lbf...!). We are now looking to mobilise a spear and surface jar set-up but looking to the wider community for any anecdotal situations with trouble recovering MS700 wearbushings that were resolved, and how.

We'll be unlatching the BOP for a visual just to check that there is no obvious damage, but the running tool engages and disengages without issue.

Suspected formation fines jammed above the wearbushing D-ring as there is no junk/trash seal on this design of bushing.

± 600ft drill floor to mudline

Any thoughts appreciated.


11 answer(s)
Drilling Specialist/Well Engineer/Training Consultant
Kingdom Drilling
Total Posts: 462
Join Date: 10/01/05


Surface jarring assembly was what would be commonly used in this situation is my understanding where yes you jar down, where its the rebound that hopefully pops the item free.

Jarring up in 600ft!!! without an accelerator is very unwise as bits would start falling off your top drive pretty quickly as there not enough stretch in pipe to absorb the hits and why surface jar is the correct tool is my understanding.

Loads are normally set low and then increased until hopefully item pops free.

To affirm this, I'll check through my fishing notes and see if I can find any documentation, best practices etc on using a surface jar. Alternatively talk to the fishing companies leading hands.

Consultant [retired Shell staff]
SPREAD Associates
Total Posts: 273
Join Date: 02/09/05

QUOTE from my "Perpetual Diary"

*1976 Semana XXV Jueves: Offshore Mar Cantábrico on board "Medusa" (Pentagone 89) Vetco 18 ¾” SG5 seat protector jammed; 30 degrees seat angle?

Since then Shell Spain "persuaded" Vetco Offshore Inc. that indeed "trash seals" were mandatory...

Shell Spain and SERVCo spotted "pipelax" and retrieved the seat protector with rotation - to minimize friction. It took time!

No wonder that "Pay for performance" is one of the ways to force both Supplier and End User to provide/specify "proven technology" and avoid repeat mishaps, like this 38 year old lesson.

Drill Supt
Total Posts: 3
Join Date: 11/02/10


Just to update on this one, unfortunately as we were mobilising the spear and jar package (ignore my prior reference to surface jars, just a bad description on my part), the weather picked up and the sensible way forward was to get off the well while the weather was favourable, rather than risk a prolonged period waiting to recover anchors.

So, the well is now long term suspended with wearbushing still in place and assumed packed off with fines.  ROV inspection showed nothing untoward.

When we come back to the well the wearbushing recovery will be the first point of action as we'll almost certainly need it to be recovered to allow the HXT to be installed for completion (though we will consider alternative tree interface options in this regard as contingency).

We've got some time to engineer a plan fully, but any further thoughts from the community would be of interest, specifically first hand experience of means to protect the wellhead H4 profile while doing open water fishing around the wellhead.




Total Posts: 112
Join Date: 10/04/08

How about the following for the stuck wear bushing:

1. Perform a jetting operation

2. Spot some acid and allow it to soak, if possible

3. Try to pull

4. No joy, run a wireline or drill pipe deployed camera system, either real-time or memory, this may need to be done on drill-pipe or through drill-pipe so you can circulate to clear fluid

5. Depending on the conditions that prevail I was wondering if circulating to cold fluid could help to strink the wear bushing enough to free it.

fishing tool hand / consultant / advisor / coordinator / tech. rep.
SPREAD Associates
Total Posts: 40
Join Date: 13/03/12
No surface jar at first, that is a down tool, spear, with stop to land out on desired profile or running / pulling tool, bumper sub, jar, drill collars (weight to suit)accelerator (or 2 depending on what weight you plan to start jarring at) (make sure jar and accelerator strokes are compatible) ... you may need the surface jar to beat it back down if it does not come the first time or two, good luck...
Drilling Supt- Benin
SPREAD Associates
Total Posts: 3
Join Date: 15/08/11
Hi Ian
Some thoughts;
  1. How long has WB been in place?  Could it be corroded?
  2. If you hoist BOP, ROV should be configured to look down into WH for confirmation, assume still only SW in place?
  3. Damage to WH seal face behind WB is definitely a concern if you are tie-ing back into that area. Suggest you get hardness spec of WH seal face vs WB as suspect WB harder matl.
  4. If you cannot retrieve WB with light jarring you may want to consider getting some warmer fluid circ around system, spotting some environmentally ok base oil for lubrication.
  5. A long shot could be the NOV (ex-Charlie Anderson) Agitator Tool to induce some vibration into either the RR tool or spear
  6. Assuming you are anchored up and don't really want to leave it for another well, maybe GE can hobble up a seal pack of some sort which would enable the RR tool to be sealed around its OD / ID of WB in order to squeeze lubricating fluid up the backside of the WB and also 'pump it up' assuming you have a cased off well below? Could be that surface pull is not in line with axis of WH so pumping it out would provide axial alignment.

John Penhale
Addax Petroleum
Total Posts: 11
Join Date: 12/11/12
You mention surface jars in your original post. Surface jars hit downward and would be of no benefit.  For upward impact you would need a spear, bumper sub, oil jars, drill collars, and accelerator jar.  A few light taps would likely knock it free.  You would think Vetco or your fishing tool company would have some experience with this.  Good luck.
Norwell Engineering
Total Posts: 24
Join Date: 17/09/07


I encounterd a similar problem in the late 90's, different WH etc but the problem was the same - we had debris 'behind' the WB (In this case I seem to remember we had swarf from a ST).  We tried flushing &  smacking it in various ways but in reality we were just getting more jammed.  We looked at lubricants but could not see a way to deploy and all were rather nasty environmentally.

In desperation we ended up cutting it in half and pulling it in two sections.  I cannot remember all the details but it was ultimately succesful.  Whether you leave it for another day or do it yourself, I suggest you start looking at the radical solution! 



Drill Supt
Total Posts: 3
Join Date: 11/02/10
Robin / Dave,

Thanks for the input.  Some concerns about the MS-1 seal integrity with heavy jarring on a stuck bushing, and it is a well that we need to get back onto in future, so can't get too rough at this stage.  Usual debate about actions now to get it out, or leave it where it is and take the time to engineer a proper recovery plan for the future.  It's never nice to leave a problem for someone later down the line though.

I will update with the outcome in due course, but any further input form experience of a similar issue would be helpful.

Snr Subsea Engineer
Dana Petroleum
Total Posts: 6
Join Date: 11/02/10
Run a bumper sub above the R/T and jar upwards HARD!
Jet like mad around the top of the wear bushing, then repeat the jarring

The 15.12" OD spear area on the running tool is not very long (about 3" from the drawing), so would you get a fishing spear in there to grip?
You could use the 9.70" ID area behind the D-ring, however keep it as high as possible to get the best pulling action on the bushing.

Managing Director (
Relentless Pursuit Of Perfection Ltd.
Total Posts: 460
Join Date: 10/01/05
Hi Ian

Sorry to hear about the problems.  I have pushed this out to the community on an urgent basis.

One guy has already come back.  He was involved in a series of subsea abandonment campigns in the North Sea.

This is what he had to say .. "My suggestion was going to be to run a spear / jar and beat the hell out of it, but I see they already plan to do that. Ian is probably right - it will be a collection of debris between the bushing and housing. I guess this is a well they want to go back to so they can't get too rough, but they can't leave it as is either?"

Kind regards


Posted by

Ian Stapleton

Drill Supt


Total Posts: 3
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