By Marianna Parraga and Deisy Buitrago HOUSTON/CARACAS, March 10 (Reuters) - International oil majors Chevron and Shell are closing in on the first big oil production deals with Venezuela since the U.S. capture of President Nicolas Maduro in January, five sources close to the negotiations told Reuters. The deals would allow both companies to boost production in coveted oil regions in the South American country, the biggest steps to date toward what U.S. President Donald ‌Trump has said would be a $100 ...