As regular readers are aware, I encourage the asking of cementing problems so that I can publish them. If one person has a question, the chances are that others do too, and we can share the knowledge.
An inbound question from a reader
Below is a summary of an answer recently given in response to a general request about tie-back casing cementing.
Sometimes I receive questions related to a specific job, and the discussion can’t get published online. The content of this page is about a non-confidential question topic.
I have categorised this post as remedial cementing according to the original request. However, we should note that tie-back cementing can be initially defined as an extension of a casing during well construction, i.e., primary cementing.
Please feel free to provide your comments or more information about tie-back casing cementing.
Tie-back casing and cementing is a remedial technique with the intention to cover a damaged intermediate casing above the top of an existing production liner. The cementing procedure follows the same principles and methods of primary cementing.
Tie-back cementing under such conditions involves important differences and additional risks.
- The use of washes and spacers ahead of cement slurries will prevent cement contamination and mixing with the fluid in the hole. (Important due to the potential incompatibility with the completion fluid or brine).
- The condition of the outer-casing should be appropriately accessed. The application of safety factors for the outer-casing burst pressure. TOC, cement density and rheology shall be selected accordingly to lower the maximum ECD.
- The dimensions and position of the tie-back tool (mule shoe) during cementing (accounting for casing elongation) shall be adequately understood and any restriction to flow shall be appropriately identified and considered in the cement job simulation.
- Plan for an adequate number of short joints of casing to prevent the cement head becoming too high above the rig floor.
- We should consider a cast iron bridge plug (CIBP). The ECD generated during the tie-back cementing operation could leak downwards and/or exceed formation pressure.
- The most important cement slurry properties are Free Water, Fluid Loss, Rheology, Gelling tendency, i.e., Cement Slurry Stability.
Need more information?
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