Well Integrity Technical Section

Dear WITS Community,

I am reaching out to seek your insights and professional expertise regarding a specific scenario in a cement packer operation. Has anyone witnessed or supervised a cement packer job using coiled tubing in a dual completion setup, where one of the tubing strings incorporates an orifice insert at a shallow depth for poorboy gas lifting?

While I have witnessed few cement packer operations in dual completions, I have not encountered one with an orifice insert in one of the tubing strings. My primary concern is whether such an operation can be executed without the risk of fluids in the casing annulus flowing back into the tubing. 

I am particularly interested in hearing about any similar operations or challenges encountered, as this would greatly aid in planning for this activity.

I would greatly appreciate your professional feedback, suggestions, or any references to similar cases you may have come across.

Thank you in advance for your time and expertise.

Kind regards,
Ayodeji

Greetings Ayodeji,

Early in my career I worked for an operator with a lot of older wells and we did a number of cement packer recompletions.  Most were in single string wells but a few were in duals.  

First of all (and I'm sure you already know this), its hard to get a good seal with a cement packer.  Pressure cycles can lead to micro-annuli between cement and tubulars, and micro-annuli can lead to sustained casing pressure.  There are many in this community who can discuss this with more authority than me.  IMO, a dual string cement packer poses more risk of failure than a single, due to both micro annuli and cement channeling.  You won't get a lot of velocity when pumping thru coil tubing.  

Then again, there are a lot of stringers and marginal zones that cannot commercially support a full workover and can only be produced by methods like this.

Installation was pretty straightforward: abandon the existing completion; perforate the tubing at the base of the proposed cement packer and establish circulation (often w/ WBM); set a cement retainer above the perfs; RIH w/ CT (or sometimes bullhead, as we did on some wells); circulate cement in place; un-sting and flush the coil if needed; and hold pressure till set.  We usually later perforated thru the cement packer into the target zone.  

But going back to your question.  Is the orifice above the proposed top of packer cement?  If "yes", no worries.  If the cement is across the orifice, it could end badly.  Even if the orifice has a check that can hold tubing pressure with zero leakage, you probably have a small window between keeping cement out of the tubing and pumping thru the retainer.  You'll also see warming and thermal expansion, making this all the more challenging.  

I had a lot of wells with po-boy Kinley gas lift orifices but never attempted to cement across one.  

Curious to see how others reply.

Good luck with your well,

R

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Ron Nelson
Subsea Completion Consultant
ron@deep-blue.ca
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