Channel-and-Bar Reservoirs ( CB Type)
thin coastal-plain alluvial sheet sandstone bodies.
Figure 15.26 shows an old isopach map of the producing zones, which suggests a lobate, deltaic form
to the deposits. However, modern, more detailed
facies analysis has yielded the map shown in Fig.
15.27, in which a complex range of interfingering
depositional systems has been identified. Traps are
521
present where the shale-out takes place updip within
Laramide structures (Chatfield 1972; Pitman et al.
1982; Fouch 1983; Fig. 15.28). Reservoir quality in
most of the fields has been enhanced by the development of fr actures and secondary porosity, and the
traps therefore also have a diagenetic component to
them (Keighin and Fouch 1981).
thin coastal-plain alluvial sheet sandstone bodies.
Figure 15.26 shows an old isopach map of the producing zones, which suggests a lobate, deltaic form
to the deposits. However, modern, more detailed
facies analysis has yielded the map shown in Fig.
15.27, in which a complex range of interfingering
depositional systems has been identified. Traps are
521
present where the shale-out takes place updip within
Laramide structures (Chatfield 1972; Pitman et al.
1982; Fouch 1983; Fig. 15.28). Reservoir quality in
most of the fields has been enhanced by the development of fr actures and secondary porosity, and the
traps therefore also have a diagenetic component to
them (Keighin and Fouch 1981).