Venezuela's deteriorating oil quality riles major refiners

By Alexandra Ulmer and Marianna ParragaCARACAS/HOUSTON (Reuters) - Venezuela's state-run oil firm, PDVSA, is increasingly delivering poor quality crude oil to major refiners in the United States, India and China, causing repeated complaints, canceled orders and demands for discounts, according to internal PDVSA documents and interviews with a dozen oil executives, workers, traders and inspectors.The disputes involve cargoes soiled with high levels of water, salt or metals that can cause problems