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Avoiding cable damage whilst Pipe-Conveyed Logging
10 October 2013
Hi folks

Our pipe-conveyed logging (earlier discussion) went well and we were able to achieve the data objectives.

However, we noted that there is potential for cable damage at surface when the slips are set.  At that moment the side-entry sub has been installed, with the cable fed through, the packoff secured and this is below the rotary table.. and now there's cable on the outside of the drillstring.

When the slips are set there is not much room for the cable which can get crimped.  We are looking at options which include:

1.  Use of grooved Bushings, with the groove cut to accommodate the cable.  That way it is recessed when the slips are set.

2.  Removing a segment of the slips.

I am familiar with Option 1. But then we get into a discussion about who will supply this; I am used to it being supplied by the electric-line company.  But, in discussions, the point was raised that there may be many different rotary openings and rigs and so it wasn't so practical to expect the logging company to provide; furthermore it involved modifying equipment normally provided by the Drilling contractor.

We'd be interested in the members' views on the above and in particular if you have come across (and overcome) any objections to modifying equipment.

Thanks and kind regards

10 answer(s)
Completions & Workover Manager
Total Posts: 11
Join Date: 11/02/10
We use slotted (105mm x 55mm) No.3 insert bowls on every completion to protect gauge cable, chemical injection line or SSSV control line from slip damage. We rent them from our tubing / casing make up company, be they BJS, Weatherford or Frank's. We do not need to cut the webbing off the hand slips because the slot is of a decent size. 
Dare say they could also be used for this application too.

Sr Subsea Equipment Engineer
Total Posts: 5
Join Date: 24/09/13
On landing strings used for completions there is a roller installed in the rotary to allow the umbilical to pass without contacting the slips. This is still a fairly critical operation as someone  has to always keep an eye on the roraty to make sure the unbilical is in the roller when the slips are set. NOV and others make this type of slip. See images copied from the NOF site.
Drilling Consultant - Frontier Operations
Total Posts: 14
Join Date: 07/03/11

Tesco has (had?) a system in the GoM for running control lines on tubing that looked pretty slick (I haven't used it - found the solution after I needed it).  That might work or be modified for the purpose.

Operations Petrophysicist
Gaia Earth Sciences Ltd
Total Posts: 14
Join Date: 21/12/11
Once further point,  with any sort of "protector tube" or "gooseneck" arrangement,  remember that the cable will be abrasive,  and you need to take into account the likely line-tensions you might be pulling - if your device is subjected to cable loading it MUST be designed with the line tensions in mind.
The line tension will be lower than in a deep wireline-conveyed job, but must be factored in to any design. 
Operations Petrophysicist
Gaia Earth Sciences Ltd
Total Posts: 14
Join Date: 21/12/11

There are commercially available bushings for this. Some simply have a slot for the cable, and some also have a roller of some sort at the top of the groove to provide a gentle profile for the cable to follow at the entry/exit to the bushing (usually the cable is held back at an angle with a snatch block, and this CAN lead to wear at the top of the bushing- I know of a job where the cable snapped at this point and 2-3 weeks fishing followed to retrieve the tools and cable)
I have a attached a couple of pictures to illustrate (these are around 10 years old now - so it is not the only style of bushing/roller available these days I am sure).

Now, with many items "recommended" there is often a bun-fight over who is to pay (I regard that as slightly different than who is to "supply").
I have seen these bushings purchased, or rented.  I have seen them "owned" by the rig or the service company or the operator.
The cost is usually insignificant when compared to NPT incurred via a damaged logging cable - one perspective.

Sometimes the Operator will say  - "we are willing to pay for them, but we want you to procure them - it will be too lengthy to get our procurement team to set up an approved vendor and get approvals etc etc. Just buy/rent them and back-charge us"
If the contracts are long term, it might be more "reasonable" to expect the logging provider or drilling contractor to buy the item - but this is best done as a part of the tendering/contracting stage. I certainly do not feel that there is a right or wrong answer.

I guess the key elements of correct procurement are the specifications - bushings correct for the rig,  and any wheel/pulley suitable for the logging provider's cable size and metallurgy (hardness)

Sometimes of course, (and not just for items like this) both the operator and drilling contractor tell the service company - "this is to help your service quality, you ought to pay".

For me, the 3 key considerations  should be:
1.  is this piece of kit a good idea and we want to have it available (whether it be for technical improvement, efficiency or safety)
2. Who is best placed to procure and order it so that we get the correct/suitable thing in the time frame we require?
3. Who will pay for it ultimately?

I would ALWAYS recommend obtaining a purpose-built, and/or designed and tested piece of kit, rather than modifying something else.   Without the slotted bushing, the key is to ensure that the slips are aligned carefully so that the natural "gap" in the slip is where the cable is. I saw my first slotted bushing in the early 90s when I was a logging engineer - the logging cable had worn a groove in the rig's bushing over a series of jobs,  and basically the drilling contractor said "you have damaged our bushing, you can keep it".  So we took it to town, machined the groove to be uniform and the size we wanted,  and then shipped the bushing out on all future pipe-conveyed jobs.

Documents uploaded by user:
Slotted Bushing for Pipe-conveyed logging.pdf
Multilateral Specialist
Multilateral Solutions
Total Posts: 36
Join Date: 30/09/13

There are several companies such as Franks, Weatherford and BJ who already have specially designed spiders to protect control lines when running intelligent or ESP completions.

They consist of automated protection systems that surround the control lines and protect them before the slips move in to bite the pipe.


They also typically have a goose neck feed system on the side to guide the control lines into the rotary and through the spiders with Teflon rollers to guide and protect the control lines.

I´m sure if required this type of equipment could be used but with modified rollers to resist the abrasion of the wire.

GBDM Renaissance
Total Posts: 3
Join Date: 02/06/09
I would speak with the TRS provider, they should have an off the shelf solution for control line or ambilical protection.
Consultant ( sort of retired but keeping in touch )
Total Posts: 33
Join Date: 27/03/11
Dave, in the '80's I used to rent grooved bushings to the likes of Expro so they could run big cables alongside pipe. We also cut the webs of the DP or Tubing slips so they could give clearance. Do not remove a slip segment.
Lowest cost is to buy the insert bowl, modify yourself ( Operator) and keep specific for such jobs. I think I still have drawings of what we did if you need them.

regards Howard.
Hess Corporation
Total Posts: 1
Join Date: 07/04/08
I have experienced this in Alaska a great deal. We ended up rubbing a groove into the rotary bushing thus having to buy a new one. The best way we found to go is to get a grooved bushing that is made for this application. If you start removing segments from slips (not sure what kind or style you are using) it greatly depreciates the weight limit the slips are made to operate with. As far as line failure we didn't have any and we did a lot of work through a side entry sub. We made sure to inspect the line on every use but never had a problem. It does however cut through the rotary bushings like butter. We had to keep turning the table on every run so it would wear in a different spot until we received our grooved bushing. Hope this helps! Good luck!
Total Posts: 87
Join Date: 10/04/08
I think it will be tricky to get anyone to modify equipment to suit your request. In a post Macondo World modifying OEM equipment is frowned upon. I suggest you have an accessory built, a cable protector that sits on the rotary table, with around a 2 foot long tube with a section cut out to allow it to be pulled over the cable with a rest plate on the top to allow it to rest on the rotary table, the rest plate being big enough, yet still light enough to lift, that prevents if falling down the hole. It would look a little like a snorkle with a flat plate attached. The plate could even have a down-wards resting pin on it that fits into one of the holes that a kelly pin would fit into. Then when the pipe has stopped moving, and before you lower the slips in, you put the Surface Cable Protector on, this shrouds the cable and ensures it is resting against the bushings and protects the cable, now when you put the slips in the opening between the slips is either side of the shroud. This way you protect the cable whilst at the same time ensure the slips are placed in correctly. I would try to leave a little clearance either side of the shroud, say 1/4", to allow for the gap in the slips being different depending on the pipe OD variance etc. If the description is not clear email me on [email protected] and I'll send you a sketch.
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