At the risk of being accused of not being able to read - don't they only own 25% of the main game? so maybe 500m barrels of they are there. Either way it would be very hard to see a market cap greater than say 600m IMO so anything over $1 would be pretty tough.
I haven't done a full look yet so happy to be corrected to $5 but that is a $3b company and that just doesn't seem realistic.