Removing carbonate scale to ensure wellbore access
Max. deviation89.72° @ 10,696 ft (3,260m) MD/RT
Max. temperature221°F (105°C)
Tubing diameter4.5" OD
On a neighboring injector well, carbonate scale deposits caused six months of down time waiting on a workover rig. Thus Total E&P Yemen, did not want to take any risks when planning a PLT operation on this well.
Communication with one neighboring well had been confirmed by interference in pressure and water-cut evolution and the aim of the upcoming PLT operation was to get the complete injection profile.
To ensure proper access to the open hole, Total E&P Yemen first did an acid pickle on the tubing one week prior to the logging job. However, the acid did not dissolve the accumulated scale; thus, an e-line scale clean out was initiated.
The Well Miller for scale removal was combined with a Well Tractor® 218 to apply weight-on-bit and counter the reactive torque from the milling bit rotation. The milling operation was performed during water injection to push deposits away from the milling bit while milling to avoiding getting stuck.
The well head initial pressure of 90 bar decreased to 1 bar atmospheric pressure because the surface pressure disappeared. The results of the subsequent PLT operation can be read in the case story: “New world record: 46,801 ft tractored in one run in open hole well”.
The Well Tractor was regarded as a revolution in the industry when it was introduced in the 1990’s. It enables operators to extend the reach of traditional e-line deployment into highly deviated and horizontal wells.
Deployed on e-line, our modular milling tools have proven to be robust and highly effective in removing well components that are malfunctioning or no longer required with robotic precision.