Stratigraphy, structure, sedimentology, and natural gas potential of the lower Cretaceous Mannville Group in the Leismer area, northeastern Alberta.

摘要

Some 1300 square miles and 450 well cores and geophysical logs have been studied, outlining current reserves of natural gas and possible further accumulations of same from the Lower Cretaceous Clearwater Formation and McMurray Formation of the Mannville Group. The McMurray Formation consists of an interpreted progression of fluvial to marginal marine deposits representing transgression of the Bullhead sea within a well defined paleovalley. The most significant natural gas reserves are found in Upper McMurray deposits where distributary channels feeding northwestern prograding shorelines have completely eroded the muds of the Middle McMurray, leaving continuous reservoir throughout the McMurray Formation. The Clearwater Formation is interpreted as northward prograding nearshore bars trapping natural gas stratigraphically to the north, and structurally to the east, primarily by the North-South trending salt collapse structure originating within the Elk Point Group. 18 maps and 9 cross-sections detail the stratigraphy, structure, and natural gas potential in the study area.