While the talks still face significant obstacles, not least whether the U.S. will participate, the bigger question is whether any deal will be enough given the extent to which the virus is destroying demand. In another sign of the growing glut, industry data provider Genscape Inc. reported a 5.8 million-barrel rise in crude inventories at Cushing, Oklahoma, last week, which would be the largest in data going back to 2004 if confirmed by official figures due Wednesday.