WELLTEC® PUNCHER CREATES 16 HOLES IN ONE RUN

Background

In late 2017, a well in the North Sea needed a work over, and the client needed to replace the Christmas tree (XMT) because of a leak. The client decided to pull the upper completion and run a new one with a new XMT. Therefore, the client needed to punch and cut 7”, 32 ppf tubing just above the production packer.

The client requested the Well Cutter® as a primary cutting tool since they needed a clean cut in order to re-enter the well and pull the deep-set plug. The client also needed to punch holes in the tubing to establish circulation.  Welltec® mobilized the Welltec® Puncher since the original plan was to run both the Puncher and Well Cutter® in combination. However, these runs were split after evaluating the time required to reverse-circulate gas from the well with a downhole temperature close to 130°C.

Further, the client initially used a third-party ballistic puncher since the punch required 16 holes, 10 more than the Welltec® Puncher had previously performed in a single run. The third-party ballistic puncher resulted in a misrun, and the client replaced the ballistic puncher with the Welltec® Puncher.

OPERATION

Welltec’s tools were used successfully for two runs during this operation: the first run with the Welltec® Puncher, and the second run with the Well Cutter®

The misrun with the ballistic puncher was thought to have failed because it could only fire in a downward position. This positioning was an issue because of the well’s 54° deviation. The Welltec® Puncher can be oriented in either a three o’clock or nine o’clock position, thereby improving the odds that the punch will result in fluid circulation. The Welltec® Puncher is a non-explosive tool that equalizes the pressures between tubular strings and drills a large 12 mm hole hole in the tubing at target depth.

To achieve the correct positioning, Welltec® used a modified centralizer mounted on a three-foot spacer above the Welltec® Puncher and Welltec Hardware Scanner (WHS). The WHS monitored and confirmed the orientation of the drill bit during the run. It took just 50 seconds for the first hole to be drilled. All 16 holes were drilled in under three hours. The average drilling time by hole was approximately 40 seconds.

The Well Cutter® was then rigged up with a casing collar locator and run in hole. The position was correlated and the Well Cutter® engaged while the tubing was under compression. The cut took only 42 minutes.

ACHIEVEMENTS

Welltec’s tools achieved the client’s objectives by punching 16 holes in the tubing during one run, a new record for the Welltec® Puncher. Then, the Well Cutter® made an efficient, clean cut that left a good entry guide for future runs in the lower completion.

Welltec® Puncher succeeded generating flow path with controlled position of equal size and penetration depth holes. This capability introduced new technology for well intervention, maximizing the likelihood of achieving good circulation.

Ultimately, using Welltec’s tools, especially the non-explosive Welltec® Puncher, resulted in a safer hole-punching and cutting option for the client.

TUBING PUNCHED AND CUT: 7” 32 ppf, L80, 13Cr
PRESSURE: 422 bar
PUNCH DEPTH: 3828.7–3824.2 m, hole 1–hole 16
CUT DEPTH: 3837m
MAXIMUM DEPTH: 21,850 ft MD
TEMPERATURE: 127°C

 

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