· Abstract

· Acknowledgments

· Introduction—Video of Exploration and Production Through Time

· Units of Measure

· Undiscovered Oil and Gas Resources in the Southwestern Wyoming Province

· Undiscovered Gas in the Mesaverde Total Petroleum System

· The Almond Continuous Gas Assessment Unit

· The Rock Springs–Ericson Gas Assessment Unit

· Undiscovered Gas in the Mesaverde–Lance–Fort Union Composite Total Petroleum System

· The Mesaverde–Lance–Fort Union Continuous Gas Assessment Unit

· Undiscovered Gas in the Lewis Total Petroleum System

· The Lewis Continuous Gas Assessment Unit

· Undiscovered Gas in the Hilliard-Baxter-Mancos Total Petroleum System

· The Hilliard-Baxter-Mancos Continuous Gas Assessment Unit

· Undiscovered Gas in the Mowry Composite Total Petroleum System

· The Mowry Continuous Gas Assessment Unit

· Undiscovered Gas in the Lance–Fort Union Composite Total Petroleum System

· The Lance–Fort Union Continuous Gas Assessment Unit

· Reservoirs That Contain the Majority of Undiscovered Gas Resources

· Live Data and Maps

· In Summary

· References Cited

The Hilliard-Baxter-Mancos Continuous Gas Assessment Unit (11.8 TCFG)

Reservoir rocks are sandstones and interbedded sandstone, siltstone, and shale deposited mainly in nearshore marine, marine shelf, marine slope, and deep basin-floor settings (Roehler, 1990). In most cases, these reservoirs are encased in marine shale. These rocks, which are included in this TPS because they are largely encased offshore marine rocks, include reservoir sandstones deposited in shoreface, tidally dominated delta front, and estuarine depositional settings (Mellere and Steel, 1995). For a detailed geologic discussion of the Hilliard-Baxter-Mancos Continuous Gas AU, see Finn and Johnson (2005a). Figure 17 shows the Hilliard-Baxter-Mancos Continuous Gas AU, the mean estimate of undiscovered gas and gas liquids in that AU, and wells from the WOGCC that have a reservoir name of Baxter, Blair, Hilliard or Steele and a completion date of 2001 or earlier.

Figure 17. Hilliard, Baxter, Steele and Mancos Shale wells at the time of the assessment (through 2001).

Figure 18 includes the same data as figure 17, with post-2001 wells added to show how drilling of the Hilliard, Baxter, and Steele Shales and the Blair Formation has progressed to the spring of 2008 (WOGCC).

Figure 18. Hilliard, Baxter, Steele and Mancos Shale wells as of spring, 2008.

Since the 2002 assessment, 199 additional wells have been completed in the Hilliard, Baxter, and Steele Shales and the Blair Formation (WOGCC).