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Cementing through Tesco Casing Running Tool
14 August 2006
We routinely drill or ream in our casing and are considering
cementing through the casing running tool (CRT) instead of rigging
up the cementing head as per normal procedure. Has anyone had
experience (good or bad) with cementing through the CRT? If so, are
there any recommendations/guidelines for using the CRT in this

Chris Schmickl
OilSearch (AUS)
13 answer(s)
Drilling Superintendent
Renaissance Offshore
Total Posts: 13
Join Date: 22/01/12
The attachments cover when when I made a plug launcher with TESCO for their top drives on all these H&P Flex rigs I had working for me.
It worked but it was really safer to make a JSA with H&P for cementing through the top drive and we (oil company) assumed all the risk and damage to the top drive. I did over 100 wells and this policy was accepted worldwide by OXY.
I hope it helps

Senior Drilling Engineer
Dubai Petroleum
Total Posts: 25
Join Date: 02/04/08
Was a sceptic at first (even looked into in-line cement heads, of which there appeared some good options), but was convinced by an operator in the US who regularly dropped the plugs without incident and or negative effects from air. No bad experiences, per se. Occasionally did not bump plugs, and or had a rare 1 or 2 leaking shoes (over 600 jobs per year on both 9 5/8" and 7" Casing jobs)....Shallow / land ops, our remedial ops were low cost; no failed FIT's, we did however run a test packer one time to test the casing, and on another occasion spotted a baryte plug and got a casing test...
Total Posts: 89
Join Date: 10/04/08
These are interesting comments, Chris does not mention if they plan to utilise cementing plugs top and bottom or top only or none at all.

There will probably be some casing jobs where no plugs can work and a calculated displacement is sufficient, although the risk of a wet shoe track could be higher, based on displacement inefficiency or if losses are experienced during the job and at the end the losses take the shoe track cement from inside the casing, when a top plug may prevent this, however disconnecting the CRT to install plugs brings with it risks am sure, a cement plug could fall from a height, may get damaged getting pushed in etc, perhaps the floats are not holding and back flow occurs making it difficult to get the plugs in.

I would have thought a CRT system combined with SSR plugs already positioned inside the casing would be favored with a drill pipe ball and dart dropping head incorporated above the CRT below the top drive. I seem to remember that Franks and Halliburton developed a patented system for this, perhaps a Franks reader can comment.

There are a number of advantages to using cement plugs when casing cementing, but I am sure that with the right planning and right set of operational circumstances cementing without plugs can be performed.

I would also consider if the floats don't hold at the end of the cement job you will have to hold the the final displacement pressure on and leave the CRT in and thus a method of closing a TIW above the CRT and flushing the top drive might be merited. One additional thing to consider is the un-wanted u-tube effect if you remove the CRT to manually install plugs, aside from the drop objects risk, is the effect this may have on your displacement accuracy, you may be in a position to close the BOP on the pipe to reduce the u-tube effect during this phase then re-open, or consider running a reduced ID orifice in the shoe track to reduce free-fall, there are also some drillable u-tube control devices available in the market.

I would have thought the relatively short time saved between laying down CRT and picking up a cement head could be out-weighed by other risks in doing so and that cementing through a top drive is perhaps down the list a little given it is at surface and can be flushed easily.

Hope the above is helpful and thought provoking. Be sure to let us know how you end up going and how you get on, lots of questions are asked on this forum but the outcome and results of the advice are not always equally shared!!
Drilling engineering director
Sonatrach Petroleum Corporation
Total Posts: 9
Join Date: 13/02/12
I do not have any experience with Tesco CRT, however I attended in Abu Dhabi an SPE conference where Statoil have presented a very interesting technical paper SPE 161086 entitled "Successful Cementing Through Bottomhole Drilling Assemblies", so I would presume some of the recommandations would apply when cementing with CRT Tool.
Consultant [retired Shell staff]
Total Posts: 244
Join Date: 02/09/05
That question was raised before and there were doubts on what to do.

I would consult with experts such as:

Bob Tessari, the inventor of the TESCo portable top drive

Harald Strand, consultant (Stavanger?) and the introducer of the NEO DRILL CWD concept

and the Drilling Contractors with more exposure to TESCo tools: Parker & Kenting.
Fluids Specialist OMV Petrom S.A.
Osterreichische Mineralolverwaltung
Total Posts: 21
Join Date: 11/12/09
We cement through CRTI regularly without problem. Only point of concern is when you release CRTI to load the second plug, the cement will fall under its own weight sucking air into the casing string. This air then ends up in your shoe track - controversial! 
Managing Director (
Relentless Pursuit Of Perfection Ltd.
Total Posts: 409
Join Date: 10/01/05
Hi folks

I'd like to (re)re-open this thread to poll our members as to who is cementing using the Tesco Casing Running Tool (CRT) and if you are doing so with the blessing of the Drilling Contractor.

Has anybody had any problems doing this ?

Kind regards

Wells Team Leader
Total Posts: 3
Join Date: 08/02/09
We started doing this in East Kalimantan on 9-5/8" jobs. We eliminated rig-up time, and created better cementing conditions by being able to go straight into the cement job after circulating. We have had no issue with cement build-up in the system, but we do displace with water so there is plenty of flushing action. Two things to consider:
1. Select your cement line tie-in point to minimise the risk of cement ending up in a quiet corner of the mud circulating system.
2. Make sure you unset the casing drive slips at the earliest opportunity as they may become difficult to release (a long period WOC, e.g. if your floats failed might be problematic).

David MacDonald
Drilling Specialist
Deepwater Drilling Advisor
Hess Corporation
Total Posts: 6
Join Date: 20/06/10
The big challenge I have always encountered with regards to this is getting the drilling contractor to agree to let us cement through the top drive. Normally they want to be covered if there are any subsequent failures of the IBOP etc.

Myles Barrett
Deepwater Drilling Advisor
Hess, Indonesia
Managing Director (
Relentless Pursuit Of Perfection Ltd.
Total Posts: 409
Join Date: 10/01/05
Hi folks,

It is nearly 4 years since this topic was first raised - there were some interesting replies.

The topic came up again at a recent DWOP that I facilitated in Jakarta.

Please may you review the discussion and update with the latest "thinking".

Thanks and kind regards

Dave Taylor
Website moderator and MD of Relentless Pursuit of Perfection Ltd
Drilling Superintendent
Myspread Users
Total Posts: 19
Join Date: 24/05/06
We have drilled a number (4) of 13 3/8 inch strings in using a
Weatherford Modified Casing Spear. This Spear arrangement is similar
to the TESCO CRT, both consist of a spear assembly and a circulating
arrangement below it.
The casing is drilled to TD. The wellhead and landing string are made
up. The complete casing string is then lowered to setting depth. Once
at depth a displacement cement job (no wiper plugs) is performed. A
good shoe is achieved by under displacing the cement. No problems
when drilling out.
To date this has worked fine for us and we plan on doing it again.
Drilling Superintendent
Total Posts: 14
Join Date: 31/10/07
Casing Running - Cementing, From our Business Unit Manager in
Aberdeen, edited by myself:

1. If the client or operator wants to reciprocate and/or rotate
during the cementing and displacing operations and the Drilling
Contractor has no objections then we cement thru the Top Drive in
combination with our Casing Drive System. We have had no problems
doing this so far. After the displacing fluid and spacer fluid has
passed thru the Top Drive and the plug has bumped just make sure the
contractor is advised to function test his Top Drive safety valve(s)
to ensure they are working OK. Also as added insurance suggest to
the Contractor to flush water thru his Top Drive to be absolutely
sure there is no cement left anywhere inside.
2. The bottom and top cementing plugs are launched by disconnecting
Tesco's Casing Drive System from the top joint of casing and
manually dropping each plug.
3. Tesco is currently developing a plug launching head that can be
used with the Casing Drive System so it doesn't need to disconnected
from the casing to drop the plugs. So far there have been no
problems the way we are currently doing it even though it's slower
than being able to proceed with an uninterrupted continuously smooth
operation. First time customers are a little concerned beforehand
but are OK with it the 2nd time around.
4. Prior to commencement of the pumping of cement always ensure that
the packer cup on the bottom of the tool is in good condition and
always have one on stand-by in case the utilized one fails for one
reason or another.
5. If the customer is not interested in reciprocating and/or
rotating then hoist the Casing Drive System up out of the way after
running casing to bottom, rig up the cementing company's cementing
head and cement the conventional way.

Due to the various changes and developments in progress regarding
Tesco's Casing Running and Casing Drilling® operations we have not
yet written dedicated cementing procedures applicable to these

Andrew Shaw
TESCO, Asia Pacific
Consultant [retired Shell staff]
Total Posts: 244
Join Date: 02/09/05
Unsure if this is ideal as I recommend the use of pipe wiper plugs
to prevent cement sheath. On a couple of occasions, cement sheath
created difficult well re-entries and complicated/cumbersome/time
consuming cement sheath removal.

See also SPE/IADC 16136 Cementing High-angle wells using cement-
expanded formation packers and/or casing rotation; Roto cemntg ER
wells. THUMS Long Beach

- KK LaFleur Casing rotation while running/cementing.

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