As regards JKX's gas, as I understand it some is already exported and gets close to the international price. Its oil also gets close to the international price (but I'm not sure whether international exports are still banned). But the rest of the gas gets roughly the local market price, so a price increase should have a marked effect on JKX's revenues and profits - and the share price.
The last set of results contain details of the average price they have been getting for the gas - but this also includes that produced in Texas - I don't think they give a detailed breakdown.
In the past IC has been enthusiastic about JKX based upon the possibility of the increased potential gas price.
And Gazprom seems to be pushing the price higher
From Interfax today
11:12 Gazprom to sell gas at $250 outside CIS in early 2006