WorldOil Oil and Gas in the Capitals Hope for improved Russian-U.S. relations has evaporated, following a U.S. congressional vote and retaliation taken by the Russian government. Venezuela offers $5 million to aid Harvey victims via Citgo Venezuela, still reeling from a fresh round of U.S. sanctions that make it harder to raise financing in capital markets, offered $5 million to help victims of Hurricane Harvey in parts of Texas through its subsidiary Citgo Petroleum Corp. Venezuela oil minister, PDVSA head to switch roles, Maduro says Venezuelan oil minister Nelson Martinez and state oil company president Eulogio Del Pino will switch roles as the South American country’s production wanes and money dries up. Schlumberger, Halliburton IOUs preserve Venezuela link, for now For Schlumberger Ltd. and Halliburton Co. the road to payment for services in Venezuela is increasingly long and winding. Venezuela scorns threat of sanctions: "We kneel for no one" President Nicolas Maduro said Venezuela’s authoritarian regime is prepared for additional retaliation from the U.S., one of the crisis-torn nation’s principal trade partners, including wide-reaching sanctions on its beleaguered economy and oil industry. Venezuela's Citgo turns to Canada for oil as crisis deepens Venezuela’s oil-supply woes are so dire that its U.S. refineries are turning to Canada for help. Threat of Venezuelan oil ban pits oil boss Hamm against refiners The prospect of a U.S. blockade of crude oil imports from Venezuela has ignited fierce lobbying in Washington pitting domestic energy producers such as oil tycoon Harold Hamm, who favor a get-tough approach, against refiners that depend on those supplies. Niche U.S. oil driller gets a shot at world's biggest reserves Venezuelan President Nicolas Maduro praised foreign companies wise enough to make deals with what he called “our beloved PDVSA.” Chevron, Total withdraw foreign staff in Venezuela amid political turmoil Repsol SA pulled all foreign workers from its oil fields in Venezuela amid a deepening political crisis, while Chevron Corp. and Total SA have removed a small number of employees, said people with knowledge of the companies. Norway’s Statoil ASA has withdrawn its expatriate staff. Oil and Gas in the Capitals Notwithstanding Latin America’s limited economic growth, exploration investments are the common denominator in the region’s major oil and gas plays.