v3.26.1
Business Segment Information - Summary of Business Segment Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of operating segments [line items]      
Revenues $ 18,448 $ 19,293 $ 17,311
Revenues from intersegment sales     0
Revenues 18,448 19,293 17,311
Operating profit or loss 1,740 1,480 (1,248)
Income from equity interests in associates and joint ventures 122 396 94
Net financial results (952) (856) (504)
Net profit / (loss) before income tax 910 1,020 [1] (1,658) [1]
Income tax (1,709) 1,373 381
Net (loss) / profit (799) 2,393 (1,277)
Acquisitions of property, plant and equipment 4,909 5,600 6,191
Acquisitions of right-of-use assets 216 444 404
Increases from business combinations  [2] 1,015    
Assets 29,439 29,391 25,035
Depreciation of property, plant and equipment [3] 2,857 2,446 3,016
Amortization of intangible assets 61 43 37
Depreciation of right-of-use assets 286 270 220
Impairment of property, plant and equipment and inventories write-down [4]   87 2,288
Net reversal of impairment losses of property, plant and equipment and inventories write-down (4) 87 2,288
Operating segments [member] | Upstream [member]      
Disclosure of operating segments [line items]      
Revenues 89 50 32
Revenues from intersegment sales 7,486 8,225 7,211
Revenues 7,575 8,275 7,243
Operating profit or loss [5] 410 515 (1,915)
Acquisitions of property, plant and equipment 3,697 4,177 4,717
Acquisitions of right-of-use assets 83 211 363
Increases from business combinations  [2] 822    
Assets 13,167 12,795 10,869
Depreciation of property, plant and equipment [3] 2,199 1,809 2,437
Amortization of intangible assets     0
Depreciation of right-of-use assets 150 154 131
Impairment of property, plant and equipment and inventories write-down [4]   79 2,288
Operating segments [member] | Midstream and Downstream [member]      
Disclosure of operating segments [line items]      
Revenues 15,157 15,901 14,977
Revenues from intersegment sales 181 122 136
Revenues 15,338 16,023 15,113
Operating profit or loss 1,167 1,356 939
Income from equity interests in associates and joint ventures 38 46 9
Acquisitions of property, plant and equipment 1,024 1,233 1,285
Acquisitions of right-of-use assets 125 205 41
Increases from business combinations  [2] 193    
Assets 11,093 10,758 9,734
Depreciation of property, plant and equipment [3] 539 516 486
Amortization of intangible assets 38 29 30
Depreciation of right-of-use assets 131 115 89
Impairment of property, plant and equipment and inventories write-down [4]   3  
Operating segments [member] | LNG and Integrated Gas [Member]      
Disclosure of operating segments [line items]      
Revenues 1,643 1,633 1,523
Revenues from intersegment sales 322 294 291
Revenues 1,965 1,927 1,814
Operating profit or loss (8) (49) (1)
Income from equity interests in associates and joint ventures 42 68 7
Acquisitions of property, plant and equipment 42 26 14
Acquisitions of right-of-use assets 0 0 0
Assets 735 720 651
Depreciation of property, plant and equipment [3] 2 2 10
Amortization of intangible assets 0 0 0
Depreciation of right-of-use assets 0   0
Operating segments [member] | New Energies [Member]      
Disclosure of operating segments [line items]      
Revenues 835 895 407
Revenues from intersegment sales 8 9 21
Revenues 843 904 428
Operating profit or loss 432 106 (64)
Income from equity interests in associates and joint ventures 42 282 78
Acquisitions of property, plant and equipment 38 37 24
Acquisitions of right-of-use assets 0    
Assets 2,502 2,524 1,877
Depreciation of property, plant and equipment [3] 34 32 15
Amortization of intangible assets 12 13 7
Depreciation of right-of-use assets 0    
Impairment of property, plant and equipment and inventories write-down [4]   5  
Net reversal of impairment losses of property, plant and equipment and inventories write-down (4)    
Operating segments [member] | Central Administration and Others [member]      
Disclosure of operating segments [line items]      
Revenues 724 814 372
Revenues from intersegment sales 1,122 1,038 765
Revenues 1,846 1,852 1,137
Operating profit or loss (336) (332) (262)
Acquisitions of property, plant and equipment 108 127 151
Acquisitions of right-of-use assets 8 28  
Assets 2,094 2,822 2,022
Depreciation of property, plant and equipment [3] 83 87 68
Amortization of intangible assets 11 1  
Depreciation of right-of-use assets 5 1 0
Consolidation Adjustments [member]      
Disclosure of operating segments [line items]      
Revenues from intersegment sales [6] (9,119) (9,688) (8,424)
Revenues [6] (9,119) (9,688) (8,424)
Operating profit or loss [6] 75 (116) 55
Income from equity interests in associates and joint ventures [6] 0 0 0
Acquisitions of property, plant and equipment [6] 0 0  
Acquisitions of right-of-use assets [6] 0 0  
Assets [6] (152) (228) (118)
Amortization of intangible assets [6] 0 0 0
Depreciation of right-of-use assets [6] $ 0 0 0
Impairment of property, plant and equipment and inventories write-down [4],[6]   $ 0 $ 0
[1] See Note 2.d).
[2] Corresponds to increases in property, plant, and equipment and intangible assets due to business combinations, see Notes 7 and 8.
[3] Includes depreciation of charges for impairment of property, plant and equipment.
[4] See Notes 8 and 26.
[5] Includes (32), (133) and (21) of unproductive exploratory drillings as of December 31, 2025, 2024 and 2023, respectively
[6] Corresponds to the eliminations among the business segments of the Group.