The following table summarizes the changes in the Company’s asset retirement obligations for the periods presented: | | | | | | | | | | | | | | | Successor | | | Predecessor | | October 11, 2016
through
December 31, 2016 | | | January 1, 2016
through
October 10, 2016 | | Year Ended December 31, 2015 | (in thousands) | | | | Asset retirement obligations, beginning of period | $ | 4,989 |
| | | $ | 2,288 |
| | $ | 1,824 |
| Liabilities incurred | 187 |
| | | 174 |
| | 133 |
| Liabilities acquired | 2,002 |
| | | 66 |
| | 178 |
| Liabilities settled | (1 | ) | | | (42 | ) | | — |
| Accretion expense | 49 |
| | | 134 |
| | 139 |
| Revision of estimated liabilities | — |
| | | 32 |
| | 14 |
| Asset retirement obligations, end of period | $ | 7,226 |
| | | $ | 2,652 |
| | $ | 2,288 |
|
|