Sub Standard Graphics 3D JPH173716 00000

Well repair via high-temperature WAB® to revive geothermal producer

  • Well type
    Geothermal producer
  • Rnewables
    Welltec pilot success in renewables market segment
  • Engineered workover
    Cost savings of USD 8 mm vs drilling of new well
  • High temperature application
    To sustain up to 550°F at full production
  • Capex-effective
    Well-rejuvenation methods
  • Location
    Philippines

Background

A prolific geothermal producer (23 MW) had to be shut in, due to significant failures within the 13-3/8” casing. After consultation with our Asia Pacific Team, Welltec® offered a 1214 Welltec Annular Barrier (WAB®) solution that would facilitate the pressure-tight base for hydro-static support to the column of cement slurry placed above it. This would negate any contamination during the curing process, resulting in a good cement operation.

The 1214WAB would also offer anchoring support to the casing string in the event of thermal contraction or expansion during production or shut-down operations.

Operations

A standard 1214WAB was adapted to incorporate non-elastomeric isolation valves and burst discs to facilitate bleed-off in the event of high-pressure steam build-up behind the casing. WAB placement was directly above the 9 5/8” casing tailpipe and set within the existing 13 3/8” casing. Second stage cementing was performed above the installed 1214WAB.

During deployment, water flooded the well to keep temperatures ≤ 212°F – full production temperatures would be 600°F. The 1214WAB supported the cement column during curing and prevented free-water/acid from contaminating the cement or reaching the surface.

Achievements

This operation represents the first time that a WAB was used to revive a geothermal well. This job also marked the first time Welltec provided services for a geothermal well (Philippines), and deployed the WAB with second stage cementing equipment in Asia.
To drill a new well would have cost the client between USD 9 million and USD 12 million.

Welltec’s solution enabled the client to execute life-of-well, CAPEX-effective well-rejuvenation measures, proving the value of engineered well remediation techniques.

WAB assembly was adapted to incorporate a high-temp sealing system, non-elastomeric isolation valves and incorporated burst discs to bleed off high-pressure steam within an application that will reach 600°F at full production.
Client

Incorporating the high temperature WAB simplified the installation process when compared to alternative products with far more complex setting procedures.

1036X518 High Temperature 812Wab Enables Shut In Well Re Lining 00000 Min

Product applied