New Wells Indicate Promising Deeper Play
Last month we published an evaluation of the stacked play potential in the Uinta Basin, showing the well performance from each of the main unconventional targets. This week, we will analyze an emerging deep target in the Uinta, the Mancos Shale, and the performance of recent wells. Using TGS Well Data Analytics, we will show how to analyze production profiles from the Mancos and how initial results up to 38 BOE/ft from modern completions have the capacity to be as much or more productive than other primary targets in the basin.
Historically, Mancos Shale horizontal development has largely been overlooked in the Uinta Basin, with only 17 wells brought on production since 2005. Compare this to the nearby San Juan Basin where nearly 400 producing horizontal wells in the Mancos have come online in the last 25 years. Since 2000 in the Uinta Basin, the Mancos has been tested on the eastern side of the basin a handful of times primarily between 2010-2017 with mixed results, and again starting in late 2023 (Figure 1). Mancos wells drilled in the 2010’s were typically completed with 1-mile laterals, while the more recent Mancos wells have been completed with 2-mile laterals. During the first 11 months of production, the 2010-2017 wells produced 27 BOE/ft of lateral length, compared to 32 BOE/ft for the new wells. The higher BOE/ft can primarily be attributed to a higher oil cut at 34% compared to 20% for the older wells. This difference is likely driven by a different completion design where the 2023-2024 wells used double the amount of proppant and frac fluid per ft.Not only do the new Mancos wells perform at a higher clip compared to the older ones, but their performance eclipses wells targeting the key benches in the center of the Uinta Basin. On a cumulative basis per foot of lateral length in the first 11 months of production, the 2023-2024 Mancos wells produced 25-38 BOE/ft (Figure 2A), slighter lower than the Mesaverde at 47 BOE/ft but higher than the other key benches (Castle Peak, Uteland Butte, Douglas Creek, and Wasatch Formation) at 15-22 BOE/ft. Cumulative oil per foot is middle of the pack at 6-11 BBL/ft for the new Mancos wells (Figure 2B) while cumulative gas per foot is second to only the Mesaverde ranging from 116-162 MCF/ft (Figure 2C). On the completions side, the Mancos averages 29% more proppant per foot than the key benches at 2,700 lbs/ft, and 16% less frac fluid per foot at 41 gal/ft (Figure 2D). Although the Mancos lies ~1000 ft deeper on average driving higher proppant loads and D&C cost, 30 additional Mancos permits have been approved in the area which will paint a clearer picture on the profitability at various price decks.
Using TGS Well Data Analytics, we were able to quickly evaluate and compare formation level well performance. For more information about TGS Well Data Analytics or to schedule a demo, contact us at WDPSales@tgs.com.
Figure 1. Mancos Shale horizontal permits (open circles) and producing wells (solid circles) in the eastern portion of the Uinta Basin.
Figure 2. Comparison of Mancos (light green and red) to other key targets in the Uinta (Uteland Butte, Castle Peak, Douglas Creek, Wasatch, and Mesaverde). (Top Left): Normalized production comparison of BOE/ft of lateral length; (Top Right): Normalized production comparison of BBL/ft of lateral length; (Bottom Left): Normalized production comparison of MCF/ft of lateral length; (Bottom Right): Proppant amount (lbs/ft) of lateral length vs. frac fluid (gal/ft) of lateral length.
