The Belarusian oil refinery Naftan has started working on claims against Russian oil suppliers, who failed to honor their contractual commitments in April. Due to problems arising from deliveries of poor quality oil in late April Naftan had to reduce its oil processing volume to 50%. The company is operating reduced workload mode now, processing the raw materials supplied via the Surgut-Polotsk oil pipeline. The losses associated with performance decrease are now calculated. In addition, because of this situation, Naftan has problems in the implementation of contractual obligations to customers.