Thousands of Nigerians are asking British judges to give them permission to sue Royal Dutch Shell Plc in London over environmental damage caused by oil spills 3,000 miles away in Africa. Lawyers for residents of the crude-rich Niger Delta believe a landmark UK Supreme Court ruling last year against a London-based miner should set a precedent. Shell, which has blocked the suit twice from entering British courts, says the litigation should be heard in the West African country.