A worker looks on at the Bashneft-Ufaneftekhim oil refinery outside Ufa, Bashkortostan, Russia January 29, 2015. REUTERS/Sergei Karpukhin/File Photo To match story RUSSIA-BASHNEFT/

An employee walks down stairs at Bashneft - Novoil refinery in the city of Ufa, Russia, April 11, 2013. REUTERS/Sergei Karpukhin/File Photo

An employee walks down stairs at Bashneft - Novoil refinery in the city of Ufa, Russia, April 11, 2013. REUTERS/Sergei Karpukhin/File Photo

An employee talks on a portable radio set at Bashneft - Novoil refinery in the city of Ufa, Bashkortostan, Russia, April 11, 2013. REUTERS/Sergei Karpukhin/File Photo

An employee walks up stairs at Bashneft - Novoil refinery in the city of Ufa, Russia, April 11, 2013. To match Exclusive RUSSIA-BASHNEFT/RUSSNEFT REUTERS/Sergei Karpukhin/File Photo TPX IMAGES OF THE DAY

A general view of the Bashneft-Ufaneftekhim oil refinery is seen outside Ufa, Bashkortostan, January 29, 2015. REUTERS/Sergei Karpukhin/File Photo

Rosneft CEO Igor Sechin attends a briefing dedicated to the signing of a contract between Rosneft and Essar Oil Ltd. companies in Ufa, Russia, July 8, 2015. REUTERS/Sergei Karpukhin/File Photo

Russia's President Vladimir Putin speaks at a news conference after the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin speaks at a news conference after the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin reacts at a news conference after the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin speaks at a news conference after the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin looks on at a news conference after the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin gestures at a news conference after the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin looks on at a news conference after the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin TPX IMAGES OF THE DAY

Alexey Miller, chief executive of Russia's top natural gas producer, Gazprom, looks on as he attends a meeting of Uzbekistan's President Islam Karimov and Russian counterpart Vladimir Putin in Ufa, Russia, July 10, 2015. REUTERS/Ivan Sekretarev/Pool

Russian President Vladimir Putin looks on as he attends a meeting with Uzbekistan's President Islam Karimov in Ufa, Russia, July 10, 2015. REUTERS/Ivan Sekretarev/Pool

Russian Foreign Minister Sergey Lavrov looks on as he attends a meeting of Uzbekistan's President Islam Karimov and Russian counterpart Vladimir Putin in Ufa, Russia, July 10, 2015. REUTERS/Ivan Sekretarev/Pool

Uzbekistan's President Islam Karimov (R) adjusts the suit of Russia's President Vladimir Putin during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin (L) shakes hands with Tajikistan's President Emomali Rahmon during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin (L) shakes hands with Kyrgyzstan's President Almazbek Atambayev during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin (L) shakes hands with Kazakhstan's President Nursultan Nazarbayev during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin (L) shakes hands with Chinese President Xi Jinping during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Uzbekistan's President Islam Karimov gestures during a meeting with his Russian counterpart Vladimir Putin in Ufa, Russia, July 10, 2015. REUTERS/Ivan Sekretarev/Pool

Uzbekistan's President Islam Karimov gestures during a meeting with his Russian counterpart Vladimir Putin in Ufa, Russia, July 10, 2015. REUTERS/Ivan Sekretarev/Pool

Russian President Vladimir Putin (R) shakes hands with his Uzbekistan counterpart Islam Karimov during their meeting in Ufa, Russia, July 10, 2015. REUTERS/Ivan Sekretarev/Pool

Russian President Vladimir Putin (R) gestures during a meeting with his Uzbekistan counterpart Islam Karimov in Ufa, Russia, July 10, 2015. REUTERS/Ivan Sekretarev/Pool

Russia's President Vladimir Putin (L) shakes hands with Chinese President Xi Jinping during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin (L) greets Chinese President Xi Jinping during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

(L-R) Tajikistan's President Emomali Rahmon, Kyrgyzstan's President Almazbek Atambayev, Kazakhstan's President Nursultan Nazarbayev, Russia's President Vladimir Putin, Chinese President Xi Jinping and Uzbekistan's President Islam Karimov walk to their meeting during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

(L-R) Tajikistan's President Emomali Rahmon, Kyrgyzstan's President Almazbek Atambayev, Kazakhstan's President Nursultan Nazarbayev, Russia's President Vladimir Putin, Chinese President Xi Jinping and Uzbekistan's President Islam Karimov pose for a picture before their meeting during the Shanghai Cooperation Organization (SCO) summit in Ufa, Russia, July 10, 2015. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin gestures during the BRICS Summit in Ufa, Russia, July 9, 2015. The BRICS emerging nations are worried about the volatility of financial markets and oil prices, Russian President Vladimir Putin said on Thursday. REUTERS/Ivan Sekretarev/Pool

Russian President Vladimir Putin (R) greets Pakistan's Prime Minister Nawaz Sharif during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Karpukhin

Russia's President Vladimir Putin (R) and China's President Xi Jinping arrive for a family photo session with leaders of the invited states during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) greets his Belarus counterpart Alexander Lukashenko during their meeting at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) greets Afghanistan's President Ashraf Ghani during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) greets Iran's President Hassan Rouhani in Ufa, Russia, July 9, 2015. Rouhani said on Thursday he was grateful to Russia for its efforts to secure an agreement at talks between six major powers and Iran on Tehran's nuclear program. REUTERS/Sergei Karpukhin TPX IMAGES OF THE DAY

(L-R) Russian President Vladimir Putin, Mongolian President Tsakhia Elbegdorj and Chinese President Xi Jinping arrive for a meeting during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Karpukhin

(L-R) Russian President Vladimir Putin, Mongolian President Tsakhia Elbegdorj and Chinese President Xi Jinping arrive for a meeting during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) meets with Iran's President Hassan Rouhani in Ufa, Russia, July 9, 2015. Rouhani said on Thursday he was grateful to Russia for its efforts to secure an agreement at talks between six major powers and Iran on Tehran's nuclear program. REUTERS/Alexander Nemenov/Pool

Russian President Vladimir Putin (R) shakes hands with Iran's President Hassan Rouhani during their meeting in Ufa, Russia, July 9, 2015. Rouhani said on Thursday he was grateful to Russia for its efforts to secure an agreement at talks between six major powers and Iran on Tehran's nuclear program. REUTERS/Alexander Nemenov/Pool

Russian President Vladimir Putin (R) meets with Iran's President Hassan Rouhani in Ufa, Russia, July 9, 2015. Rouhani said on Thursday he was grateful to Russia for its efforts to secure an agreement at talks between six major powers and Iran on Tehran's nuclear program. REUTERS/Alexander Nemenov/Pool

Russian President Vladimir Putin gestures during the BRICS Summit in Ufa, Russia, July 9, 2015. The BRICS emerging nations are worried about the volatility of financial markets and oil prices, Russian President Vladimir Putin said on Thursday. REUTERS/Ivan Sekretarev/Pool

Russian President Vladimir Putin gestures during the BRICS Summit in Ufa, Russia, July 9, 2015. The BRICS emerging nations are worried about the volatility of financial markets and oil prices, Russian President Vladimir Putin said on Thursday. REUTERS/Ivan Sekretarev/Pool

BRICS countries leaders and delegates attend the BRICS Summit in Ufa, Russia, July 9, 2015. The BRICS emerging nations are worried about the volatility of financial markets and oil prices, Russian President Vladimir Putin said on Thursday. REUTERS/Ivan Sekretarev/Pool

Russian President Vladimir Putin (C) attends the BRICS Summit in Ufa, Russia, July 9, 2015. The BRICS emerging nations are worried about the volatility of financial markets and oil prices, Russian President Vladimir Putin said on Thursday. REUTERS/Ivan Sekretarev/Pool

Russian President Vladimir Putin (R) talks with his Belarusian counterpart Alexander Lukashenko during their meeting at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Ilnitsky/Pool

Russian President Vladimir Putin (R) gestures during a meeting with his Belarusian counterpart Alexander Lukashenko at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Ilnitsky/Pool

Russian President Vladimir Putin waits for the arrival of his Belarus counterpart Alexander Lukashenko during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Ilnitsky/Pool

Russian President Vladimir Putin (R) shakes hands with his Belarus counterpart Alexander Lukashenko during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Ilnitsky/Pool

Russian President Vladimir Putin waits for the arrival of his Belarus counterpart Alexander Lukashenko during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa hosts the BRICS and the Shanghai Cooperation Organization (SCO) summits on July 9-10. REUTERS/Sergei Ilnitsky/Pool

(L-R) Brazil's President Dilma Rousseff, Indian Prime Minister Narendra Modi, Russian President Vladimir Putin, Chinese President Xi Jinping and South African President Jacob Zuma pose during a family photo session at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (L) and Chinese President Xi Jinping leave after a family photo session at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (L) talks with Indian Prime Minister Narendra Modi (C) as they walk for a meeting followed by (R-L) Brazil's President Dilma Rousseff, Chinese President Xi Jinping and South African President Jacob Zuma during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin?

Russian President Vladimir Putin (L), Indian Prime Minister Narendra Modi (3rd L), Brazil's President Dilma Rousseff (C), Chinese President Xi Jinping (4th R) and South African President Jacob Zuma (2nd R) walk after the welcoming ceremony during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) greets Brazil's President Dilma Rousseff during the welcoming ceremony at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) shakes hands with Brazil's President Dilma Rousseff during the welcoming ceremony at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) greets Indian Prime Minister Narendra Modi during the welcoming ceremony at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin arrives for the welcoming ceremony during the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) greets South African President Jacob Zuma during the welcoming ceremony at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin

Russian President Vladimir Putin (R) greets Indian Prime Minister Narendra Modi during the welcoming ceremony at the BRICS Summit in Ufa, Russia, July 9, 2015. Ufa is hosting the BRICS and the Shanghai Cooperation Organization (SCO) summits from July 9-10. REUTERS/Sergei Karpukhin