1. 1. Baker Hughes, 2022, Rig Count: https://rigcount.bakerhughes.com/ (accessed May 2022).
2. 2. Brown, B.W., 1972, Origin of petroleum geology: AAPG Bulletin, v. 56, no. 3, p. 566-568, https://doi.org/10.1306/819A3E8A-16C5-11D7-8645000102C1865D.
3. 3. Cook, T.A., 2013, Reserve growth of oil and gas fields-Investigations and applications: U.S. Geological Survey Scientific Investigations Report 2013-5063, 29 p., http://pubs.usgs.gov/sir/2013/5063/.
4. 4. Cumella, S. P., and D. B. Ostby, 2003, Geology of the basin-centered gas accumulation, Piceance Basin, Colorado, in K.M. Peterson, T. M. Olson, and D. S. Anderson, eds., Piceance Basin Guidebook: Rocky Mountain Association of Geologists, p. 171-193.
5. 5. Cumella, S.P., 2006, Overview of a giant basin-centered gas accumulation, Mesaverde Group, Piceance Basin, Colorado: The Mountain Geologist, v. 43, no. 3, p. 219-224.