Abstract: Fluid Migration, Hydrochemistry and Entrapment in the Red River Formation, Williston Basin, Canada - USA

MARGITAI, ZSOLT, University of Alberta, Department of Earth and Atmospheric Sciences, Edmonton, Alberta

Recent prolific oil and gas discoveries in Saskatchewan, Canada from Lower Paleozoic strata in the Williston Basin have renewed interest in those formations as exploration targets. Hydrocarbon migration and entrapment in deep formations (Red River Formation, in particular) remains relatively unstudied and poorly understood. Thus, the overall goal of the project is to quantify migration and entrapment in those strata, thereby improving exploration efficiency.

In the first phase of the study, data will be collected (temperature, pressure, chemistry, source rocks, maturity, fluid and rock properties) in order to calibrate published models and to determine oil families and the distribution of oil sources and hydrocarbon generation. Phase two will be the construction of potentiometric surfaces and oil flow patterns to investigate the effects of gravity-induced flow on hydrodynamic regime and on accumulation of hydrocarbons. Finally the influence of distribution of evaporites and dolomitization on migration and accumulation of hydrocarbons will be considered.

Producing wells will be sampled for brine and oil. The study of brines is important because of the rather unknown effects of variable salinity fluids that might alter the pathways of oils. Samples will be analyzed for chemical and isotopic concentrations. Physical properties determined from the samples (e.g. density) will be used as inputs for future hydrogeological phases of the study. By means of using these techniques the importance of understanding the movement (or stagnation) of groundwater in the exploration of hydrocarbon occurrences and the role of moving water will be emphasized.

AAPG Search and Discovery Article #90931©1998 AAPG Foundation Grants-in-Aid