Signatory

Every quarterly case is prepared and signed by Klaas Kostro, a reservoir engineer for 24 years: simulation at Schlumberger, then seven years inside operating companies on North Sea fields, and since 2010 an independent consultant on fields in the North Sea, Russia, Africa and North America.

His work is the work behind a reserves report: matching models to history, probabilistic forecasting, reserves reporting, and technical due diligence for around a dozen acquisitions and financings.

He signs because a price opinion is worth exactly what its author is willing to put on the record.

What a signature means

Every quarterly case is computed by the published model, then read, questioned and signed by the named engineer before publication. The signature states who did the work. Every quarterly case is issued by Reservoir GmbH, and the engineer signs for the company. The cryptographic signature on the public archive is a proof of integrity and authorship: it shows a case has not been altered since signing. It is not a legal signature. Nothing on this site may be relied on by anyone. Neither Reservoir GmbH nor the signatory has any financial interest linked to the Brent price.

Corrections

Published quarterly cases are never edited. An error is corrected by issuing the next quarterly case, which states what was wrong with the earlier one. Both stay online.

Basis of opinion

Each case reflects the professional judgement of Reservoir GmbH, based on accepted standards of professional practice, the public data named in the case and the method published with it. It is not a promise of any outcome, and actual prices may fall outside the stated range. Reservoir GmbH has not independently verified the public data it uses and has relied on them as published. The opinions are subject to, and fully qualified by, the uncertainties that come with interpreting data, and do not reflect every circumstance that could affect decisions made by readers or actual outcomes. They are given in good faith and in the belief that they reflect the physical and economic circumstances prevailing on the date of issue.