Downhole water management

Challenge
Water shut-off
Water management case - Well Intervention - Welltec
  • Max. depth 12,300 – 12,400 ft
  • Max. deviation 68°
  • Max. temperature 194°F

Background

Welltec’s downhole mechanical services enable enhanced production from mature fields to prolong the life of wells and increase productivity. A wide range of services are available including removal of obstructions such as scale and fill, reducing gas to oil ratio and isolating water-producing zones as illustrated in the case below.

A well in the North Sea producing since 1995 was isolated with tubing that included two Sliding Side Doors (SSD) to control production. Attempts had been made to close both SSDs in 2003, but only the upper SSD had closed. A two-piece straddle assembly was set above the lower SSD, which, however, did not change production. A PLT test showed there was an internal leakage in the tubing. In 2006, the straddle was retrieved and the well temporarily plugged.

Operation

The operator decided to apply Welltec’s downhole mechanical services.

The Well Tractor® and Well Stroker® were used to isolate the lower sliding side door with a 72 ft long straddle assembly and to isolate the hole in the tubing above the lower straddle with a 26 ft straddle.

Achievements

The four-run operation was successful.

The 85% water rate was reduced to 5% and the oil production went from 1,258 BOPD to 5,660 BOPD.