Changes

'''By Bruce Hart, Western University, London, Ontario, Canada'''

'''By Bruce Hart, Western University, London, Ontario, Canada'''

[[file:Figure1MancosCommRept.jpg|300px|thumb|{{figure number|1}}Type logs through the Cretaceous section of the San Juan Basin, showing the principle stratigraphic units. Note the interval commonly drilled in the Offshore Mancos Shale play. Modified from Hart<ref name=Hart>Hart, B. S., 2021, Stratigraphy and Hydrocarbon Resources of the San Juan Basin: Lessons for Other Basins, Lessons from Other Basins: The Mountain Geologist, in press.</ref>.]]

[[file:Figure1MancosCommRept.jpg|300px|thumb|{{figure number|1}}Type logs through the Cretaceous section of the San Juan Basin, showing the principle stratigraphic units. Note the interval commonly drilled in the Offshore Mancos Shale play. Modified from Hart<ref name=Hart>Hart, B. S., 2021, Stratigraphy and Hydrocarbon Resources of the San Juan Basin: Lessons for Other Basins, Lessons from Other Basins: The Mountain Geologist, v. 58, p. 43-103.</ref>.]]

Sharp reductions in demand for oil and gas dramatically affected drilling in the San Juan Basin of New Mexico and Colorado. This summary focuses on the Mancos Shale play in the period 2017-2020 although other unconventional targets (e.g., tight-gas plays of the Dakota and Mesaverde, CBM from the Fruitland Coal) have been drilled and produced for more than 70 years. [[:file:Figure1MancosCommRept.jpg|Figure 1]] shows a type log through the Cretaceous section of the San Juan Basin.

Sharp reductions in demand for oil and gas dramatically affected drilling in the San Juan Basin of New Mexico and Colorado. This summary focuses on the Mancos Shale play in the period 2017-2020 although other unconventional targets (e.g., tight-gas plays of the Dakota and Mesaverde, CBM from the Fruitland Coal) have been drilled and produced for more than 70 years. [[:file:Figure1MancosCommRept.jpg|Figure 1]] shows a type log through the Cretaceous section of the San Juan Basin.