Rosangela B. Z. L. Moreno

Simulation of Polymer Flooding considering Size Model Increase and Economical Evaluation

The water flooding is widely used because it is relatively simple and inexpensive. However, this method presents some disadvantages. Since water is usually less viscous than the heavy oil, the water tends to arrive soon and in large quantities at the producer well, resulting in a low oil production due to the low swept efficiency. These conditions motivate the use of advanced recovery methods, and among them, polymer injection stands out. In this paper, the oil recovery by water injection alternated with polymer slug (WAP) is compared with continuous water flooding (WF). Variations on slug size, injection starting time of the polymer slug, relative permeability curves, polymer viscosity and mobile oil saturation were evaluated. Subsequently, the model was submitted to a size increase, and these results were used in economic analysis based on the net present value (NPV). The information obtained helps to understand how the oil recovery factor is influenced by changes in flooding conditions. The upsizing process doesn’t present distortions when comparing different scale models. The differences in oil recovery factor and water-oil ratio were lower than 0.2%. The integration of EOR results and oil prices encourage the project viability analysis.

Water Injection, Polymer Injection and Polymer Alternating Water Injection for Enhanced Oil Recovery: A Laboratory Study

Developing an efficient methodology for oil recovery is extremely important in this commodity industry, which may indeed lead to wide spread profitability. In the conventional water injection method, oil displacement occurs by mechanical behavior between fluids. Nevertheless, depending on mobility ratio, a huge quantity of injected water is necessary. Polymer injection aims to increase water viscosity and improve the water/oil mobility ratio, thus improving sweep efficiency. The alternating banks of polymer and water injection appear as an option for the suitable fields. By doing so, the bank serves as an economic alternative, as injecting polymer solution is an expensive process.The main objective of this study is to analyze and comparison of the efficiency of water injection, polymer injection and polymer alternate water injection. For this purpose, tests were carried out offset in core samples of sandstones using paraffin oil, saline solution and polymer and were obtained the recovery factor and water-oil ratio for each method. The obtained results for the continuous polymer injection and alternating polymer and water injection were promising in relation to the conventional water injection, aiming to anticipate the oil production and to improve the water management with the reduction of injected and produced water volumes.© 2013 ASME

Dynamic Evaluation of Invasion and Backflow in Carbonate and Sandstone Reservoirs

This work aims to compare the drilling fluid invasion and oil backflow in sandstone and carbonate samples in order to evaluate the influence of kind of rock in the formation damage and its interaction with the drilling tested fluid.The tests were performed in sandstone and carbonate samples with similar gas absolute permeabilities and under a protocol test in steps that included preparation, characterization, multiphase flow, drilling fluid invasion and oil backflow.During the work it was observed that carbonate samples were less water wet than sandstone samples. From the obtained results for longer samples was possible to follow the advancing front of the invading fluid with pressure observations along the core. The dynamic flow permitted to conclude that invasion in carbonate samples was faster than in sandstone. It was also observed that in carbonate samples the backflow presented a higher and faster productivity return when compared with sandstone results.Copyright