Critical isolation in deep water

Well completion
WAB - Welltec Annular Barrirer - case story JCO151381
  • Well type Heavy oil producer
  • Reservoir type Sand
  • Product / placement 612WAB / open hole
  • Successful water injection Reaches planned production plateau earlier
  • Enhanced well construction reduces Risk of water production
  • Capex & opex effective Zonal isolation increases reserve recovery
  • Welltec and client collaboration Upgraded qualification enables flexible deployment
  • Location Congo


An IOC in Congo had cement placement concerns due to a combination of 6 ½” open hole across a short, deviated reservoir section and 4 ½” liner, therefore resulting in low volumes of cement across this deviated section.

Conventional solutions considered would result in increasing cement volume:
Under reaming to 7 1/8” = extra rig time.
Shoe track extended = breakthrough into the oil / water contact.

Within this challenging application, zonal isolation was critical to optimizing acid stimulation pre-flush.


Welltec Annular Barrier® (WAB) forms a combined barrier with cement for acid stim and water isolation.

WAB installed and expanded on a single trip with liner hanger.


Caliper log run indicating good hole at WABs setting depths. Qty three WABs made up as part of the liner BHA, spaced out for zonal isolation and water isolation. Plug bumped and all WABs expanded, quickly under surface control, in wet cement.


WAB for slim hole cement assurance prevents water production.

Well completion
1036X518 Jco151381 612Wab Enables Critical Isolation In Deep Water Application Webformat Min