San Juan Basin, NM
September 15, 2021
This new paper describes and analyzes the petroleum system of the Mancos Shale in the San Juan Basin with a focus on the recent offshore Mancos play. The reservoirs in the offshore Mancos play are fine-grained, low-permeability sandstones interbedded with shales. These sandstones are carrier beds that link the shale source rocks that generated the oil in the deep, northern part of the basin with the conventional, coarser-grained and higher permeability conventional sandstone reservoirs in the shallow southern part of the basin. The conventional sandstone reservoirs were mostly developed in the 1950’s and have produced most of the oil in the basin. Unlike the conventional sandstone reservoirs which were developed with vertically drilled wells, development of the carrier bed reservoirs is enhanced by the new technique of drilling wells vertically to the target zone and thence horizontally through the target zone for distances of one mile or more. The paper appears in a special issue of the AAPG Bulletin that focuses on carrier bed oil reservoirs. This is the first-ever volume published on the subject of carrier bed reservoirs. Broadhead, R.F., 2021, The offshore Mancos play in the San Juan Basin as a component of the Mancos total petroleum system: AAPG Bulletin September 01, 2021, Vol.105, https://doi.org/10.1306/01152120038.