1.   But when hydrogen is extracted from gas, the residual carbon must somehow be disposed of, possibly by pumping it back into depleted oil and gas wells.

2.   Gas wells typically poses less environmental threat than oil wells, considering the consequences of a catastrophic oil spill.

3.   Houston-based Pride provides rigs and other equipment and services used to drill oil and gas wells on land and in water.

4.   In Seminole, Halliburton and other major companies that treat oil and gas wells to enhance production packed up and moved.