Case Study

Reducing reservoir uncertainties during field appraisal

In Brief

Reducing uncertainty in reservoir connectivity during Clair Field Appraisal 

Customer Challenges

  • The Clair Field is located 75km west of Shetland in water depths of up to 140 meters. It comprises a naturally fractured sandstone reservoir, which over the scale of the Clair Field made reservoir connectivity and compartmentalization risk key uncertainties for field development planning
  • The 206/8-13Y Clair Ridge appraisal well was located 8km from the existing Clair production platform and designed to confirm the next stage of development of the field
  • An opportunity was identified to instrument the well with a CaTS gauge at the time of final abandonment, thus converting it to a long-term monitoring asset. Observing for interference effects resulting from production or injection events on adjacent assets would demonstrate wide-scale reservoir connectivity

Expro Excellence

  • A Drill Stem Test (DST) was performed on the well using a permanent packer and tailpipe
  • On completion of the final pressure build up, a CaTS gauge was conveyed into the well throughtubing and hung off below a bridge plug set at the bottom of the tail pipe
  • The DST string was then recovered to surface and the well permanently abandoned in accordance with the applicable UK regulations
  • After installing a CaTS subsea receiver on the seabed, the rig departed the abandoned well location allowing the reservoir pressure and temperature data being transmitted from downhole to be collected at the receiver
  • Provides a unique wireless reservoir monitoring solution in a permanently abandoned subsea appraisal well

Value to Client

  • 18 months of high-quality reservoir data was recovered from the permanently abandoned subsea appraisal well at low incremental well cost
  • The correlation of the reservoir pressure responses and trends between the Clair phase 1 platform and the Clair Ridge appraisal well provided clear evidence of reservoir connectivity
  • Cost effective Advanced Reservoir Testing in an abandoned subsea appraisal well provided high value data to steer the future development planning on Clair

Contact

For further information, please contact wireless@expro.com.