Abstract
The scope of this abstract is to highlight the complexities that arise when attempting to plug and abandon (P&A) smart well completions. Just about every well that has a smart completion design includes flat pack equipment. Flat packs are commonly used when several different lines are terminated at approximately the same depth in the well. Common applications include intelligent well systems, deep-set chemical injection lines with downhole gauge cable and safety valve lines with shallow set chemical injection lines.
As part of the complex P&A operation the upper completion of the well must be retrieved. To retrieve the upper completion, the production tubing and the flat pack must be cut or severed completely. If the cut is partial there is a high probability of losing complete sections of control line and associated debris in the well bore. This debris can potentially negate the possibility of providing a clean and secure well abandonment, not to mention the high cost of non-productive time (NPT) due to fishing operations to remove the debris.
Two System Integration Tests (SIT) were completed to prove the concept of cutting through pipe and a flat pack within a single operation, one with a 5 ½″ 23ppf S13Cr 95ksi pipe inside of a 10 ¾″ casing and the second was with a 6 5/8″ 28ppf S13Cr 95ksi inside 10 ¾″ casing. Prior to inserting the 5 ½″ pipe into the casing, a flat pack was strapped to the external wall of the pipe. A section of the casing wall was cut out to install an acrylic window to visualize the cutting operation and evaluate its effectiveness. The cutting tool was inserted into the tubing and placed in position to make the cut of the pipe and the flat pack with control lines. The cutting process took approximately 2 hours for both tubing sizes. The tool was able to successfully cut the tubing and the flat pack in two tests. Based on these results, the solution was deployed on an actual operation in 2021 with excellent results described in this paper.
This cutter technology can be used for other size tubing and casing combinations. The time it takes to make the cut is considerably less than having to clean up the well bore after attempting to retrieve the upper completion using other less effective cutting methods. This cutter technology can make multiple cuts in a single run, and it can also be used to cut multiple casings. No explosive or chemicals are used to make the cut.
