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Through 3-1/2" Tubing Milling
23 November 2015

Dear all,

We plan to Coil Tubing milling 7" cement retainer, this will be through 3-1/2" tubing milling BHA.  The motor will be less than 3 in.  The cement retainer was set but no cement, so the milling will be through the ID of the retainer.

Does anyone has success for the same job?  Any issue related with the small motor stabilization?  And also proper milling type?

Any information would be appreciated.

Thanks.

Sanny


3 answer(s)
KenHorne1
Multilateral Specialist
Multilateral Solutions
Total Posts: 32
Join Date: 30/09/13
Hi there Sanny.

Can you share what you have planned to do going forward?  Its always good to get the follow up on a planned operation.

Regards

Ken
Euan Docherty
Technical & BD Expertise (ML, ESS, Liner, Smart Well)
SPREADAssociates
Total Posts: 1
Join Date: 07/10/15
Hello Sanny,

Ken is right (as always), getting some empirical data will reap dividends for these types of projects. I supervised the PDO Toothpick project in 1998 - all good clean fun with lots of learning tangents...we were milling casing exits, drilling a new lateral and running the liner all with the baker GA3 hybrid coiled tubing unit. using new mud motors always gave significantly better results, watch out for stalled motor and reactive torque, take it easy milling and don't get the CT stuck with debris. You may want to investigate Diamond Speed Mills - low torque and small particles for easy circulation. One other point of interest is the emergency disconnect, watch out for the correct balls being dropped for circa subs etc - get a witness to double/tribble check all balls... plan for success you you will be fine. If you need more info just let me know... also watch out for trapped pressure under the plug...

Euan.......
KenHorne1
Multilateral Specialist
Multilateral Solutions
Total Posts: 32
Join Date: 30/09/13

Sanny.

I don´t have any BHA information to pass on, however I would suggest you sit down with the supplier of the cement retainer (CR) and compile a drawing of how the mill will contact and mill through the CR.  As the plug will be +/-6.00” and you mill will be less than 3.00” it´s very likely that you will not be milling through the centre of the CR as the milling BHA will be laying on the low side of the liner/casing.  This may result in milling through a small portion of the plug and its slips and who knows what the result will be.

I would always start with a simple drawing to replicate the situation and if you have the time and ability, a workshop mock up using some liner and tubing and a BHA or replica BHA to then discuss the way forward before going to the well.

Regards

Ken..................


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