| 13 |
Oil and Gas Extraction |
|
131 |
Crude Petroleum and Natural Gas |
|
|
1311 |
Crude petroleum and natural gas |
|
132 |
Natural Gas Liquids |
|
|
1321 |
Natural gas liquids |
|
138 |
Oil and Gas Field Services |
|
|
1381 |
Drilling oil and gas wells |
|
|
1382 |
Oil and gas exploration services |
|
|
1389 |
Oil and gas field services, nec |
