Siccar Point Energy has announced that the Blackrock exploration well, 204/5b-2, has encountered oil in a number of thin sandstones, though it has not been declared commercial. The prospect sits on the Corona Ridge between the Cambo and Rosebank fields and was targeting 200mmbbls in the Paleocene Flett reservoir, which rests on the volcanics of the Colsay Member. Gas was also encountered in the overlying Hildasay member. The well was the first to test the additional potential of Siccar’s acreage around its Cambo field, which it estimates could be up to 1.5bnbbls.
The sandstones were interbedded within a 34m gross package of intra-volcanic siliclastic sediments. The presence of thin sands is not surprising given that Rosebank and Cambo also contain thin inter-bedded reservoir units, however Siccar has stated that it will use the Blackrock well data to define and target thicker reservoir packages, suggesting that the sands were thinner than expected. In addition any further appraisal would need to demonstrate the connectivity of the sands as this can be a challenge within thin sand packages. In 2018, Siccar, together with partner Shell, drilled an appraisal well at Cambo and established excellent reservoir quality and test rates of ~5000bbls/d of dry oil. The analysis of the extended well test results also showed that the reservoir was well connected, and the partnership is currently progressing towards development sanction for the field. If commerciality can be demonstrated with further appraisal, Blackrock could be tied back to any future development at Cambo or Rosebank.
Blackrock was highlighted in our ‘Exploration Watch: 2019 exploration wells’ report.
Summary of exploration wells in Exploration Watch report
|Blackrock||Oil and gas|