Hydrodynamics and Petroleum Migration in the Red River Formation, Williston Basin, Canada and U.S.A.

Benjamin J. Rostron¹, Daniel K. Khan¹, and Zsolt Margitai^2
1 University of Alberta, Edmonton, AB
² Safety Codes Council, Edmonton, AB

The Red River Formation has been, and still is, an important hydrocarbon exploration target in the Williston Basin. This unit and its equivalents form a widespread flow unit across the basin. Given the active regional groundwater flow system in the basin, hydrodynamics plays a role in the migration and entrapment of petroleum in this unit. To better understand the migration of petroleum in the Red River Formation, a regional study of the hydrodynamics and oil migration in this formation was completed.

Present-day water chemistry and regional groundwater flow-directions were mapped across the basin. Results showed the presence of saline brines and also significant density-dependent groundwater flow-effects. Present-day oil migration directions were examined using: i) hydrostatic, ii) un-corrected hydraulic heads, and iii) density corrected driving forces, in conjunction with variable oil densities. Results showed that near the recharge area in the west/southwestern portions of the basin that hydrodynamics plays an important role altering the up-dip rate and direction of migration of oil. Analysis of the paleo-migration of oil was conducted by attempting to reconstruct the structure of the basin at key time (generation) events. Results showed different oil migration patterns in the past compared to the present day.

A better understanding of petroleum migration in the Red River Formation is obtained by incorporating hydrodynamics and paleo-structures into migration analysis.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005