Deductions 17F1 Excess Intangible Drilling Costs 20T1 Oil & Gas - Total Sustained Assumed Allowable Depletion 20T2 Oil & Gas - Cost Depletion (Working Interest) 2073 Oil & Gas - Cost Depletion (Royalty) 20T4 Oil & Gas - Percentage Depletion in Excess of Cost Depletion to the Extent of Basis (Working Inte