NUI Workover

NUI WORKOVER

Background

The platform was a gas producer and was located in the Southern UKCS. It is a Normally Unmanned Installation and as such had significant restrictions in terms of available beds, deck space, and crane limitations.

Objective

The objective was to workover a gas producer which had proven communication between the tubing and annulus. ISS were involved from the get go on this project with a desk engineer working full time in the clients office assisting in writing the program and providing technical advice.

Execution

  • Upfront an E-line cutter was used to cut tubing just above the packer.
  • Pumping package was rigged up and Well kill performed.
  • Unit was rigged up directly under the crane on a skidding Package due to crane not having sufficient height over Well Center.
  • Unit skidded over to Well and attempt to pull tubing was made, tubing would not come.
  • Decision made to run in with Chemical cutter on slickline.
  • Tubing began moving on second attempt.
  • Significant corrosion was seen on the connections of the retrieved tubing.
  • All tubing was pulled out of hole and new completion successfully run.
  • Limited deck space meant equipment package had to be optimized.
  • Operation had to be carefully planned due to only 22 beds in total and no dedicated boat during operations.

Results

Operation was planned from the drawing board to completion inside 4 months.
Well was successfully re-completed and brought back on line.
Unit was rigged up directly under the crane on a skidding Package due to crane not having sufficient height over Well Centre.
Operation was completed on time with minimal weather delays. No support vessel was required during the entire operation.
Great team work displayed by all parties on board.