| Many reservoirs in Saskatchewan and Alberta have bottom-water zones underlying the oil zone. Waterflooding such reservoirs can be ineffective if the oil has a high viscosity. The injected water bypasses the oil and causes earlier breakthrough at the producing well and as a result does not displace much oil. Efficiently the presence of bottom-water zone results in poor areal and vertical sweep efficiencies. However, waterflooding still remains the most widely used oil recovery technique for bottom-water reservoirs. This thesis study addresses some key technical problems of waterflooding in such reservoirs.; With the use of polymer solutions, in this study, the need has developed to understand this mobility control mechanism.; An experimental study was conducted by using a physical model, which consists of a three-dimensional flow system packed with Ottawa sand in two layers, one saturated with oil and water and the other with water only.; A three-dimensional three-phase black oil commercial simulator (CMG/IMEX) was used in this study to simulate water/polymer flood experimental data.; The results of the two models showed good agreement and confirmed that oil recovery during a waterflood in a bottom-water reservoir is sensitive to injection rate, oil viscosity, crossflow, polymer solution concentrations, and water-to-oil formation thickness ratio. By using a combination of horizontal production and vertical injection the wells showed better oil recovery than vertical production injection or horizontal production/injection wells in the presence of a bottom-water zone. (Abstract shortened by UMI.)... |
