Changes

===Unconformities and subcrops===

===Unconformities and subcrops===

[[Mapping unconformities|Surfaces of unconformity]] can be especially useful [[Marker|marker horizons]] for structure contour mapping ([[:file:subsurface-maps_fig2.png|Figure 2]]). In many fields, unconformities are the location of sealing shales and/or source rocks above reservoir pay. [[Subcrop maps]], traces of productive zones, barriers, or marker horizons mapped on the unconformity surface are invaluable for planning well placement and for [[Field development|reservoir development]].

[[Mapping unconformities|Surfaces of unconformity]] can be especially useful [[Marker|marker horizons]] for structure contour mapping ([[:file:subsurface-maps_fig2.png|Figure 2]]). In many fields, unconformities are the location of sealing shales and/or source rocks above reservoir pay. [[Subcrop map]]s, traces of productive zones, barriers, or marker horizons mapped on the unconformity surface are invaluable for planning well placement and for [[Field development|reservoir development]].

===Pressure===

===Pressure===