JOINT FILERS’ NAMES AND ADDRESSES
| 1. | Name: | R/C ENERGY IV DIRECT PARTNERSHIP, L.P. |
| Address: | c/o Riverstone Holdings LLC | |
| 712 Fifth Avenue, 19th Floor | ||
| New York, NY 10019 | ||
| 2. | Name: | R/C IV LIBERTY HOLDINGS, L.P. |
| Address: | c/o Riverstone Holdings LLC | |
| 712 Fifth Avenue, 19th Floor | ||
| New York, NY 10019 | ||
| 3. | Name: | R/C ENERGY GP IV, LLC |
| Address: | c/o Riverstone Holdings LLC | |
| 712 Fifth Avenue, 19th Floor | ||
| New York, NY 10019 |