812WAB® isolates shale collapse on exploration well

Well abandonment
WAB - Welltec Annular Barrirer - case story JMA181487
  • Well type Gas / appraisal
  • Reservoir type Sandstone
  • Isolation of shale collapse Provided tangible DST results from producing zone
  • Open hole placement of wab Isolated any potential for shale collapse
  • Wab application versatility enabled Preferred well methodology
  • Operational focus ensured All objectives met in this challenging application
  • Location Malaysia


A vertical carbonate exploration well in the Ginseng field, Petronas offshore Malaysia, was expecting heavy losses and possible shale formation collapse.

This was the client's first exploration well since the downturn. After installing the completion the client planned to do well testing before completing P&A of the well.


Welltec® offered a Welltec Annular Barrier (812WAB7.5:5) solution as a primary plan as part of a contingency liner to isolate total losses and support the formation from shale collapse above. The 812WAB was made up as part of the 7’’ contingency liner and expanded to 8-1/2’’ OH size.

As no losses were encountered. The WAB was installed to support the formation from shale collapse. The lower completion consisted of a 812WAB mounted on 4-1/2’’ base pipe was made up and x-over to the 7 in liner. The WAB & liner hanger was set simultaneously against the 3-1/2’’ pre-installed HPHT bridge plug.


This was the second successful WAB installation for this IOC following on from the installation within a cemented mono-bore campaign. The WAB supported the formation from shale collapse allowing the successful evaluation of hydrocarbon potential via well testing. Zero Non-production time.

Due to well changes during drilling i.e. no losses, the setting of the WAB was constantly changing. This was of substantial benefit to the client, due to the versatility of the WAB and being able to set in open hole or cased hole.


The WAB’s application versatility, allows for adaptive changes in well design during milestone exploration well.

Well abandonment
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