He has been trying since 2007 to change foreign oil contracts from production-sharing agreements, under which the foreign producers can have partial ownership of the fields they operate, to servicing contracts, under which the producers would have to pay a production fee and then get reimbursed for the cost of their investment.
ExxonMobil earlier in the decade had won a key battle against Russian oil companies by obtaining a production-sharing agreement, which gave it more protection against arbitrary tax increases.
Under a production-sharing contract, an oil company would recoup its costs and then be entitled to a proportion of the oil extracted, instead of being paid a fixed fee for each barrel.