End Polluter Welfare Act of 2021 This bill limits or eliminates certain fossil fuel oil and gas subsidies for oil companies, including by (1) eliminating the limit on liability for offshore facilities and pipeline operators; (2) eliminating the authority of the Department of Energy to carry out the Fossil Energy Research and Development Program and prohibiting funds made available to the Advanced Research Project Agency from being used to carry out any project that supports fossil fuels; (3) terminating certain provisions relating to enhanced oil recovery, producing oil and natural gas from marginal wells, and limitations on percentage depletion for oil and natural gas wells; (4) terminating other deductions and accounting methods supporting oil, natural gas, and coal companies; (5) increasing the Oil Spill Liability Trust Fund financing rate; (6) denying a tax deduction for removal costs and damages relating to oil spills; (7) imposing an excise tax on the removal price of any taxable crude oil or natural gas; (8) increasing amortization periods for tertiary injectant expenses, development expenditures of a mine or other natural deposit, mining exploration expenditures, and intangible drilling and development costs for oil and gas wells and geothermal wells; (9) repealing the tax credits for the production of electricity from refined coal and for carbon oxide sequestration; and (10) requiring a study and elimination of certain other fossil fuel subsidies.