BAINES, DAVE, University of Calgary, Dept. of Geography, Calgary, AB, Canada

ABSTRACT: Stratigraphic Profiling to Detect Reservoir Connectivity of Channel-Fills and Crevasse-Splays

The purpose of this project is to examine the fluid connection (aquifer continuity) between channel sands and crevasse-splay sands. Current depositional models suggest that these deposits are connected. However, no field work has been done in modern systems to assess the extent and location of these connections. This project will survey modern buried channel-fills and crevasse-splays using a state-of-the-art, high resolution, shallow geophysical method to improve depositional and stratigraphic models of low energy fluvial systems.

This project's regional setting will consist of: (1) the upper Rhine-Meuse River Delta in the Netherlands and (2) the anastomosing channel reach of the upper Columbia River Valley in British Columbia, Canada. In the Rhine-Meuse Delta, the project will examine Holocene channel belts (sandy meandering and anastomosed channel bodies in clay and peat) incised into the Pleistocene substrate (generally sand and gravel braidplain). In the Columbia Valley, the project will examine an actively anastomosing system with sand channel-fills and crevasse-splays buried in silty clays. Both sites provide an excellent analog for reservoirs in the ancient rock record.

Surveys utilizing electrical resistivity ground imaging (an advanced form of multielectrode DC resistivity) to generate high resolution cross sectional imagery, confirmed with borehole data, will be used to produce stratigraphic profiles. Multiple surveys will allow three dimensional modeling and the creation of a visualization tool to examine the sand body geometry, orientation, and interconnection. This will provide a modern analog and tool for locating reservoir `sweet-spots' and assessing reservoir connectivity.

AAPG Search and Discovery Article #90909©2000 AAPG Foundation Grants-in-Aid