Page 285 - Applied Petroleum Geomechanics

274 Applied Petroleum Geomechanics

Figure 7.29 Pore pressure profile in ND and MT, USA based on analyzing 92 bot-
tomhole pressure and DFIT data points, a number of hydrostatic points at eastern
margin, six Sanish-Parshall points in the Middle Bakken and additional data of the
Three Forks (Theloy, 2014).

generation in both Upper and Lower Bakken shales correlates to formation
overpressures.

7.5.8.3 Haynesville and Bossier shale plays
The Bossier and Haynesville shales are tight shale gas reservoirs with very
low matrix permeability (0.00007e0.0007 mD). The lithology comprises
the Tertiary-, Cretaceous-, and Jurassic-aged stratigraphic units character-
ized primarily by claystones (shales) and sandstones. There are also lime-
stone formations, such as the Knowles limestone in the Cotton Valley
Group and the Smackover limestone at bottom of the Haynesville shale
(Fig. 7.30). Regional correlation sections across northern Louisiana reveal a
prominent mid-Cretaceous unconformity, suggesting a later uplift event
affecting the area. It appears that the present-day Sabine High represents a
Tertiary uplift event. The maximum missing section due to the Tertiary
uplift is estimated in orders of several thousand feet. Timing of the uplift
and erosion appears to be the Oligocene Epoch (Zhang and Wieseneck,
2011).