Once the drilling is complete, specialized equipment manages the extraction of hydrocarbons. A wellhead at the surface of the well can withstand upward pressure of escaping gases and fluids. Natural gas, the least dense material, will often naturally rise to the surface. A “christmas tree,” a series of pipes and tubes about 6 feet high, can be installed to regulate the flow of hydrocarbons. Some crude oil and natural gas must be lifted by a special pump, called a pump jack. The crude oil, natural gas and sometimes brine (or saltwater) is then separated for further processing. A conventional separator is where the force of gravity serves to separate the heavier liquids like oil, from the lighter gases, like natural gas, which is shipped out through an elaborate series of pipelines to processing plants or storage facilities.
The natural gas enters a compressor station before entering a pipeline, where it travels at pressures anywhere from 200-1,500 pounds per square inch (psi). Compressor stations are placed at 40-100 mile intervals along a pipeline in order to increase the volume of natural gas being transported (up to 600 times) and maintain appropriate pressurization. Interstate pipelines are typically 24–36 inches in diameter and all pipelines are made of steel or plastic with corrosive protection and maintenance records are kept on all repairs.
Pigging describes various processes that allow for inspection and maintenance of a pipeline from within the pipeline itself. If maintenance is needed, specialized pigs can be used to remove debris, paraffin build-up or give a video inspection within the pipe. “Smart pigs” have become increasingly sophisticated, targeting specific types of pipeline issues that may restrict the flow of materials through the line.
Constructing pipelines takes a great deal of planning and preparation including feasibility studies to ensure that a route provides the least impact to the environment and public infrastructure already in place. In addition, safety precautions may include aerial patrols, leak detection devices, pipeline markers, and earthquake-proof braces that allow for minor shifts in the earth.