But at last week's closing of $114, the price of each of those barrels of Ural crude, the country's main export blend, has risen 24 percent since the beginning of the year.
The price for Urals crude, the country's main export blend of oil, was 46percentt higher in January through November from the same period a year ago, while prices for natural gas increased 26.7percentthethe ministry said.
It produces about $127 million worth of oil a day, based on average prices last year for Russia's export blend oil, Ural Crude, and sells some of it to a similarly opaque commodities firm called Gunvor based in the Netherlands and co-owned by Gennady Timchenko, another longtime acquaintance of Mr. Putin.
The paper considers the following operations in the oil depot: delivery, export, blending, fractionation and maintenance.
The MILP model, considering the constraints of delivery, export, blending, fractionation, maintenance, switching, oil and contaminated oil tank, contaminated oil batch and time node, is solved by MATLAB 2014.
Objective: Minimize the total costs of delivery, export, blending, fractionation and tank switching operations of all the oil tanks during the study horizon to schedule the oil tanks' detailed operation under various operational and technical constraints.
Aiming at making a scheduling plan with the lowest operating costs, the paper establishes a mixed-integer linear programming model, considering a sequence of operations, such as delivery, export, blending, fractionating and exchanging operations, and batch property differences of the same oil as well as influence of batch migration on contaminated volume.
Urals, Russia's main export crude blend, traded at $30.96 a barrel on Thursday.
No oil tank is allowed to do delivery, export, switch, blending and fractionation operations simultaneously at the same time.
According to formula (8a, 8b), the blending capacity's percentage for export oil blended with different kinds of contaminated oil is a constant value.
The blending capacity of an oil tank is the sum of its blending capacity of last moment, delivery, recycle and switching oil's blending capacity during this period minus export oil's blending capacity.
