Hydrogeochemistry of pre-Mississippian brines, Williston basin, Canada-USA

Spatial variations of solute chemistry in basinal brines have been used to determine the origin of formation waters and to infer regional patterns of fluid flow and dominant diagenetic processes active in the Williston Basin, Canada-U.S.A. Preliminary results of a regional, 200 well sampling program in pre-Mississippian formations, show that these brines involve three chemically distinct waters. A CaSO sub(4) brine (TDS300,000 mg/l) is located in the deepest part of the basin, while a Na-Cl brine is found in the remaining volume.