UK Stocks-Factors to watch on Nov 20

Britain's FTSE 100 index is seen opening 14 points lower at 7,074 on Tuesday, according to financial bookmakers. * ROYAL DUTCH SHELL: The heavy-oil hydrocracker at Royal Dutch Shell Plc's 209,787 barrel-per-day (bpd) Convent, Louisiana, refinery may be shut for two months of repairs, said two sources familiar with plant operations. * OCADO, KROGER: Kroger Co has chosen its hometown of Cincinnati for the first of 20 high-tech warehouses it plans to build with UK