Devonian Shale Gas
Devonian shales were formed in a shallow sea that covered the eastern half of what now constitutes the continental United States. Devonian shale gas is defined as natural gas produced from the fractures, pore spaces, and physical matrix of shales deposited during the Devonian period of geologic time.
Gas shales are classified as continuous type natural gas plays, and represent accumulations that are pervasive throughout large geographic areas and offer long-lived reservoirs. In contrast to a conventional gas reservoir, shale is a self-sourced reservoir where source rock and reservoir rock are combined into a single geologic unit. In general, shale reservoirs in the Company’s properties have the following characteristics:
- Low production rates (30 mcf/d to 100 mcf/d)
- Cover very large geographic area
- Long production lives (up to 60 years)
- Low decline rates – less than 5% per year
- Ability to be thick (140 feet to 175 feet)
- Typically organically rich
- Contain large gas reserves (.180 bcf to .3 bcf per section);
- Rely on natural fracture systems for porosity and permeability;
- Usually requires some type of stimulation to be economical.