Based on the unique problem description, Welltec engineered a custom solution consisting of a Well Tractor®, Well Stroker®, Well Miller® and a variety of bits. The plan, as designed, was to mill through the safety valve in stages to remove the inner mandrel sleeves. This in turn would release the springs that were holding the dogs and subsequently dislodge the valve. A System Integration Test (SIT) was conducted beforehand to confirm the solution for this project’s objective.
Using the Well Tractor and Well Miller plus custom nipple milling bit in combination with the Well Stroker the team succeeded in milling out the safety valve as planned during the SIT. The safety valve fell to the bottom of the well as desired, restoring access and production.
This successful milling operation enabled the operator to avoid having to pull the entire completion string and saved more than USD 2 million compared to the alternatives. The operator was very pleased to be able to regain the well in a shorter time frame and estimated that the milling solution was twice as efficient as the other options.
MAX. DEV.: 54.4° @ 9,567 FT (2,916 M)
WELL FLUID: GAS
MIN. RESTRICTION: 4.437” @ 28 FT (8.5 M)
MAX. TEMPERATURE: 304°F (151°C)
MAX. PRESSURE: 3812 PSI