CARBON DIOXIDE ENHANCED OIL RECOVERY AND SEQUESTRATION IN THE BEAVER LODGE OIL FIELD WILLIAMS COUNTY, NORTH DAKOTA

Geologic carbon sequestration has become a viable method to reduce anthropogenic carbon dioxide (CO₂) emissions and affects to the atmosphere. Permanent storage of CO₂ in mature petroleum reservoirs and saline aquifers allows for continued use of fossil fuel energy while reducing the environmental impacts. Combining CO₂ sequestration and CO₂-enhanced oil recovery (EOR) in mature oil and gas reservoirs allows more hydrocarbon to be retrieved than previously possible, which also offsets part or all the sequestration cost. The purpose of this project is to develop the most effective method of producing hydrocarbon beyond secondary recovery from mature oil fields and store a significant amount of CO₂ in the process. The identification and classification of suitable sites for this method is necessary to ensure the method does not damage producing pools or allow CO₂ to be released to the atmosphere during or after injection. The Beaver Lodge oilfield in Williams County, North Dakota is selected as the initial case study for the identification of sequestration and EOR potentials. The Beaver Lodge is a multiple-pay field located along the N-S trending Nesson anticline in western North Dakota. Production occurs in nine separate horizons, but the Devonian Duperow Formation was selected for initial modeling based on higher porosity, production history, and good well control. The industry software, ECLIPSE, is used to model the field in three dimensions incorporated with well log data. Porosity, permeability, and rock strength measurements were independently verified from core plug analysis to ensure accurate modeling data for both reservoir and cap rocks. Physical modeling of the core samples under in-situ pressure and temperature is used to measure the changes of rock properties as nitrogen and CO₂ gas are injected into the sample. After completion of the Duperow Formation modeling and sample analysis, work on the other eight horizons will be conducted.