Machinery installation, maintenance and repair; oil drilling; gas drilling; construction of structures for the production of crude oil; construction of structures for the storage of crude oil; installation of oil production apparatus; construction of structures for the production of natural gas; construction of structures for the storage of natural gas; construction of structures for the transportation of natural gas; drilling of wells; drilling of deep oil or gas-wells; electric appliance in...

Machinery installation, maintenance and repair; oil drilling; gas drilling; construction of structures for the production of crude oil; construction of structures for the storage of crude oil; installation of oil production apparatus; construction of structures for the production of natural gas; construction of structures for the storage of natural gas; construction of structures for the transportation of natural gas; drilling of wells; drilling of deep oil or gas-wells; electric appliance in...