To estimate the FFO / Net debt ratio for Eni S.P.A. at the end of 2022 (using 2023-01-01 balance sheet figures for the period ending 2022-12-31), we apply the standard S&P methodology:

**1. Calculate Funds From Operations (FFO):**
S&P typically defines FFO as Cash Flow from Operating Activities adjusted for certain items (like the change in working capital).
*   Cash Flow from Operating Activities: 17,460,000,000 EUR
*   Adjustment for change in working capital (to reverse its impact): -1,279,000,000 EUR
*   FFO = 17,460,000,000 - 1,279,000,000 = 16,181,000,000 EUR

**2. Calculate Net Debt:**
S&P Net Debt is Total Debt minus Cash and Cash Equivalents (and sometimes other liquid assets).
*   Total Debt = Short-term borrowings + Current portion of long-term borrowings + Long-term borrowings
*   Total Debt = 4,446,000,000 (Short-term) + 3,097,000,000 (Current portion) + 19,374,000,000 (Long-term) = 26,917,000,000 EUR
*   Cash and Cash Equivalents = 10,155,000,000 EUR
*   Net Debt = 26,917,000,000 - 10,155,000,000 = 16,762,000,000 EUR

*(Note: While other adjustments like pension liabilities or lease liabilities are sometimes included in S&P adjusted debt, using the provided financial statement items directly for core debt components is the standard approach for this calculation.)*

**3. Calculate the Ratio:**
*   FFO / Net Debt = 16,181,000,000 / 16,762,000,000 ≈ 0.96533...

Rounding based on typical financial ratio presentation:

<answer>0.9653</answer>