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The Energy Council

is a nonprofit trade organization that promotes safe and responsible oil and natural gas development in La Plata County. Individual and company members work to build community relations, increase public understanding, and address public issues relative to the industry.

Gas Facts : Conventional vs. Coalbed Gas Wells

There are two types of natural gas wells in La Plata County, conventional and coalbed. Conventional gas wells are typically deeper (3,500 - 10,000 feet) and extract gas and oil from sandstone formations such as the Mesa Verde, Mancos Shale and Dakota. Coalbed gas wells generally range from 1,000 to 4,000 feet deep and extract gas from coal-bearing formations. The Fruitland formation is La Plata County's methane-rich coalbed formation.

Conventional wells initially produce large volumes of gas and very little water. Over time gas production declines and water increases. Coalbed wells are just the opposite, producing large quantities of water and low gas quantities at the beginning and, later, the water production declines and gas production increases.

Pump jacks at well sites are used to pump water and sometimes oil -- not gas. On a conventional gas well a pump jack is not necessary at the beginning, but may be added later to remove the increasing amounts of water. On a coalbed well, a pump jack is typically needed during the first few years and can be removed as the amount of water declines.

Conventional and coalbed methane gas wells are significantly deeper than domestic water wells. Natural gas wells are separated from the surrounding surface formations by "casings" discussed below. Geologic studies show that beds of nearly impermeable shale separate deep and shallow aquifers and retard vertical water movement.