At December 31, 2017 and 2016, intangible assets are wells unassigned to a reserve, which amounted Ps. 9,088,563 and Ps. 8,639,242, respectively as follows:
| 2017 | 2016 | |||||||
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Wells unassigned to a reserve: |
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Balance at the beginning of period |
Ps. | 8,639,242 | Ps. | 14,304,961 | ||||
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Additions to construction in progress |
20,553,952 | 20,526,300 | ||||||
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Transfers against expenses |
(3,663,986 | ) | (9,798,246 | ) | ||||
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Transfers against fixed assets |
(16,440,645 | ) | (16,393,773 | ) | ||||
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Balance at the end of period |
Ps. | 9,088,563 | Ps. | 8,639,242 | ||||
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