An operator in the Middle East had several corrosive high-pressure wells which were shut in due to stuck coiled tubing. The well design and status eliminated options for conventional work-overs, so the fish had to be recovered to surface utilizing a Hydraulic Workover Unit and specialist Thru-Tubing fishing equipment. This required highly experienced fishing & milling personnel who could ensure the correct equipment was used for each run-in hole, thereby enabling a safe and efficient operation.
Successful execution was based on detailed up-front planning and application of thru-tubing well intervention services for high pressure/high temperature (HP/HT) conditions. The ideal operation would include selection of the right personnel, technology and bottom-hole assembly (BHA) configuration that would offer:
Built-in contingencies for pressure control.
Meet the material selection guidelines for operations in the corrosive environment.
Allow for adequate consideration for all possible contingencies that may arise during the operation.
Following this careful up-front planning, more than 1,082 runs were carried out in 15 wells. More than 68,000-ft of coiled tubing, with sizes ranging from 1.250in. -1.750in, was recovered to surface. In total, more than 42,664 man-hours were completed with Zero LTIs and Zero NPT.
This paper serves to highlight the value that competent up-front planning, equipment selection and choice of personnel adds to an extremely high profile and complex fishing campaign. This allowed complex fish to be recovered, restoring production without the need for a costly work-over operation and ultimately saved the operator from major expense.