Expensive oil and big new projects have boosted the value of international energy firms' stake in the Middle East, but they must still battle for access to the region's reserves, consultancy Wood Mackenzie said. Overall asset values have been increased by around 87 percent as major projects have been approved in Qatar, Abu Dhabi and Oman.
Other projects have stalled over political difficulties and international companies have access to less than 10 percent of the region's oil and gas reserves.
National oil companies all individually hold much larger reserves and far more valuable upstream portfolios than any international company in the region.
"Patience, persistence and pragmatism remain pre-requisites for success," the Edinburgh-based consultancy concluded in its latest report, entitled Positive developments for international oil companies in the Middle East.
"Although several development contracts have been awarded over the past year, other long-awaited projects in Iran, Iraq and Kuwait continue to be delayed," said senior Wood Mackenzie analyst Colin Lothian. "Political uncertainty in Iran and the continued instability in Iraq continue to hinder contract awards, whilst Project Kuwait remains sidelined by differences between government and parliament".
International companies have already been waiting around a decade for the opening up of Kuwait's oil reserves through a scheme labelled Project Kuwait, which has been repeatedly blocked by conservative political elements.
Wood Mackenzie finds ExxonMobil holds the most valuable upstream portfolio and has stretched its lead at the top of the table. Its estimated value of around $18 billion is dominated by giant gas and LNG assets in Qatar and supplemented by its newly-acquired 28 percent share of the super-giant Upper Zakum oilfield in Abu Dhabi.
Royal Dutch Shell and Total, which rank second and third respectively, retain largely the same portfolios as last year, although their buy-back contracts in Iran through which foreign firms are repaid with proceeds from oil output have matured.
Both companies have also benefited from improved expectations of oil price, enhancing the value of their assets in Oman and Syria.