Natural gas rigs are a unique picture of shale drilling. Further, it has components that are required for getting natural gas from the consumer to the well.
Natural gas is transported via pipelines from individual wells to larger interstate pipelines and then to consumers across the United States. As shale development continues in Pennsylvania, West Virginia and Ohio, additional pipeline and compressor infrastructure is needed to deliver the product from well to consumer.
Gathering pipelines deliver the natural gas from the wells to the larger interstate and transmission pipelines. Gathering lines run from two to 30 inches in diameter, depending on the volume of gas running through them.
These pipelines are generally made of steel and are buried in a permanent right of way. Pressure is required to move the gas from the wells to the larger pipelines.
Although natural gas comes out of the ground under pressure, additional pressure may be needed to move the gas to the larger lines, and this pressure is commonly provided by compressor stations. The number, spacing, and size of compressor stations depend on the number of wells, production and distance between stations. There may be one or more compressor engines per station in which the natural gas moves through.
These engines can run on natural gas, diesel or electricity, and are normally found in buildings for noise abatement and ease of maintenance in inclement weather. Tanks may be on the site to store water and gas condensate that is removed from the natural gas, as it moves through the compressors.
In some regions, there may also be a glycol dehydrator that removes excess water from the gas to make it ‘dry’ enough to travel through the main pipelines. A compressor station may not be manned around the clock, but they are often fenced and lit and have security measures in place.
Meter stations are needed for accurate measurement and accounting of all natural gas delivered to the interstate pipelines. Meter stations can also regulate gas pressure. These stations are normally a small building enclosed by a fence that is visited by an industry representative several times a week.
Valves along the pipeline work like gateways. They are normally open to allow the gas to flow, but may be closed to stop gas flow in a section of pipeline that needs maintenance. Launchers can also be found along pipeline right-of-ways.
A launcher is a pipeline access that can be used for inserting a device, tool or vehicle to move through the pipeline interior for inspecting, dimensioning, or cleaning. These tools are commonly referred to as ‘pigs’ because of the occasional squealing noises made as they pass through the pipeline.