| hydraulic fracturing for natural gas | 1.53 | 1 | 6280 | 36 | 95 |
| hydraulic fracturing to obtain natural gas | 1.02 | 0.7 | 9566 | 42 | 21 |
| hydraulic fracturing and natural gases | 0.88 | 0.4 | 1780 | 38 | 64 |
| hydraulic fracturing natural gas burner | 0.7 | 0.1 | 4740 | 39 | 74 |
| hydraulic fracturing natural gas energy | 1.29 | 0.2 | 8765 | 39 | 68 |
| hydraulic fracturing oil and gas | 1.37 | 0.6 | 8408 | 32 | 89 |
| hydraulic fracturing fracking and shale gas | 0.51 | 0.2 | 660 | 43 | 14 |
| hydraulic fracturing shale gas | 0.68 | 0.6 | 2524 | 30 | 82 |
| what is hydraulic fracturing | 0.96 | 0.1 | 3744 | 28 | 48 |
| what is hydraulic fracturing fracking | 1.19 | 0.1 | 7637 | 37 | 32 |
| facts about hydraulic fracturing | 1.15 | 0.8 | 1686 | 32 | 93 |
| water and nitrogen hydraulic fracturing | 0.05 | 0.3 | 9652 | 39 | 39 |
| fracking for natural gas | 1.46 | 1 | 6165 | 24 | 7 |
| hydraulic fracturing fracking services | 1.24 | 0.3 | 4131 | 38 | 95 |
| high energy gas fracturing | 1.42 | 0.2 | 3813 | 26 | 81 |
| fracking for oil and natural gas | 1.4 | 0.8 | 6840 | 32 | 9 |
| fracturing oil and gas | 1.75 | 1 | 5155 | 22 | 52 |
| hydraulic fracturing and horizontal drilling | 1.15 | 0.3 | 7187 | 44 | 85 |
| hydraulic fracturing & health | 1.51 | 0.2 | 7207 | 29 | 23 |
| natural gas and fracking | 0.79 | 0.1 | 4208 | 24 | 87 |
| solutions to hydraulic fracturing | 0.6 | 0.4 | 5270 | 33 | 11 |
| fracking natural gas extraction | 1.29 | 0.5 | 1685 | 31 | 58 |
| hydraulic fracturing in soils and rocks | 1.72 | 0.1 | 4935 | 39 | 48 |
| what is hydraulic fracking | 1.93 | 0.1 | 9154 | 26 | 15 |
