CLE.OFF.NO.10.08.V1 MILLING SCALE AND SETTING BRIDGE PLUG ON E LINE

Milling scale and setting bridge plug on e-line

  • CROSSFLOW LIQUID RATE
    300-400 Sm3/d
  • WATER CUT
    Approx. 70%
  • WATER CUT FROM ZONE 2
    Approx. 45%
  • MAX. DEVIATION
    83° (@ nipple milling depth)
  • MIN. RESTRICTION IN WELL
    2.81" @ 10,207 ft MD
  • MAX. EXPECTED SIWHP
    110 BAR

Background

An oil producing well completed in 2002 with eight Sliding Side Doors (SSDs), four remote and four manually operated. In March 2008, scale build-ups were observed in the well when running a PLT log. The PLT tool stopped in a remote operated sleeve for zone 3 due to scale deposits confirmed by high gamma ray readings. On a shut in pass, the PLT showed a crossflow from the lower zones (3, 4 or 5) into zone 2. During the production logging, a hole in the tubing in zone 2 was detected at 10,555 ft MD RKB (below the mechanical sleeve in zone 2) .

After this leak occurred, the pressure decreased in an adjacent well producing from the same zone and that well was considered dead due to insufficient reservoir pressure. Zone 3 was in communication with that well but there was not enough pressure support in the area to produce both wells.

Operation

The main objectives were to mill out the scale and install a retrievable plug with a flapper valve below zone 2 to avoid production from zones 3, 4 and 5. The purpose of the flapper valve was to be able to inject into these zones in case it would not be possible to remove the plug.

The second objective was to open the remote operated sleeves in zones 3 + 4 because of future plans of injecting into these zones. Due to higher time efficiency and cost effectiveness, the Well Tractor® and Well Miller® were selected to remove the scale build-up inside the wellbore. A Well Miller 212 and a Well Tractor 218 XR (Xtra Reach) were chosen to run in and open up the scale obstruction and thus provide the required final ID.

The scale was successfully removed from the well in two days. For the plug setting operation, Welltec® rigged up with the Well Tractor® 218 XR, a 2.71” OD hydrostatic setting tool and a 2.65” packer with a dual flapper valve installed at the bottom. The plug was successfully installed at 11,824 ft MD. Total time for the plug setting was 4.5 hours.

Achievements

The client obtained all the objectives for the operation that was executed quickly and safely. Access to the reservoir was re-established for further operations and the operation eliminated heavy lift requirements.

Tools Applied

  • Well Miller® for Hardware Milling

    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.

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  • Well Tractor®

    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.

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