According to a Bloomberg article titled Break-Even Points for U.S. Shale Oil, Niobrara shale oil is still profitable at $80 bbl the in the Wattenberg Hz. Wattenberg Tier 2 profitability is marginal at an oil price of $80 bbl with an average break even price at $84.98 bbl. Wattenberg wells in Tier 1 areas are on average, profitable at $55.38 bbl.
A detailed description of the gradational nature of shale plays and how plays are classified into tiers is available from Kimmeridge Energy.
“Shale plays are gradational in nature (see exhibit 5) (to the right), with a variety of thicknesses, depths, TOC, mineralogy, maturity, etc, across the play fairway,
which can be many thousands of square miles.
The core of the play occurs where the confluence of these different parameters is optimal. So for example, a confluence of good thickness, high TOC, requisite maturity, high porosity, suitable mineralogy, etc, is most likely to offer the best development economics across the play, although this needs to be proven through subsequent drilling and de-risking.” (Kimmeridge Energy)
A full article describing the gradational nature of shale oil plays is available from Kimmeridge Energy in an article titled Defining the Core of Shale Plays – Lessons from Cutting-Edge Research and Practical Experience