The new estimate was produced by Gaffney, Cline & Associates (GCA). It covers the Jade, Topaz and Pearl prospects, and, it represents a 9% upgrade from a prior estimate of 814mln barrels.
GCA also estimated a Geological Chance of Success of Jade and Topaz prospects, at 32% and 30% respectively.
"The independent review of three prospects, recently undertaken by GCA, is very encouraging and supports the work undertaken internally by Empyrean,” said Tom Kelly, Empyrean chief executive.
“It is particularly pleasing to see that the Jade and Topaz prospects are expected to have close to a 1-in-3 chance of geological success and over a billion barrels of potential oil-in-place, combined, on a P10 basis un-risked.”
Kelly added: “By industry standards, these numbers are excellent.
“The work done by GCA certainly supports Empyrean's view on the potential size and attractiveness of these prospects.
“We are excited by the increased potential of Block 29/11 and of the attractive GCoS of our two main prospects, in particular.
“We made a determined effort to secure Block 29/11 in 2016 and have made a significant investment and commitment. It is pleasing to see independent expert validation of a major component of our work so far as we work towards unlocking value for our shareholders.”