The report from Colorado-based MHA Petroleum Consultants estimates that four of the upper sand units contain about 51.4 million barrels of oil in place, according to Elk.
This figure was derived from recently completed RST (Random Stratified Testing) well logs, carbon-oxygen modes conducted on zones of interest and the re-analysis of historic well logs.
Elk said its confidence in the report was further enhanced by hydrocarbon shows reported in the upper sand units during the drilling of historic wells and production in these horizons in nearby oil fields.
The company first announced the possible existence of hydrocarbons in the upper sand units in Wyoming in its December quarterly report, following unexpected oil flows from temporarily abandoned wells.
Elk now plans to undertake an appraisal program to define proven recoverable reserves.
Based on a 35% historic recovery from original oil in place estimates in the currently producing Muddy Formation in the Grieve Oil Field, Elk said the upper sand units could result in the recovery of about 18 million barrels of light sweet crude.
In addition to planning the appraisal program, Elk will prepare a reservoir model and development plan for the exploitation of each sand unit.
The company said it had also started assessing the carbon-oxygen mode RST well logs and historic well log data to identify additional upper sand units.
“The identification of new hydrocarbon reservoirs is an exciting development for the company and represents an opportunity to achieve a considerable uplift in production from the Grieve Oil Field,” managing director Robert Cook said.
“Together with the redevelopment of the Muddy Formation, the evaluation of the deeper Cloverly Formation, the redevelopment of the Sand Draw South Oil Field and a successful acquisition strategy, the company is progressing well with its aim of becoming a significant oil producer in the near term.”