Pressure Pulsing Potential During Waterflooding and CO2 Flooding of Heavy Oil Reservoirs

Abstract

The world is facing a challenge of limited sources with respect to hydrocarbons. Society has become so dependent on oil and natural gas that no one can imagine life without the resources. Oil and gas deposits are limited and the main portion of conventional reservoirs is at a late stage of development, hence, the market price for oil and gas is continuously increasing. The need for development of new technology for oil recovery from unconventional reservoirs has become a priority. Canada owns more than 40% of the world’s heavy oil. This means traditional methods of oil displacement, namely waterflooding or immiscible gas injection, could lead to a very low recovery factor. Thermal and chemical impacts on a reservoir are the main methods of increasing sweep efficiency and recovery factor. Nevertheless, the first method is pricy and the second is environmentally unfriendly and expensive. Pressure Pulsing Technology (PPT) does not change the properties of the hydrocarbons or reservoir, it changes the flow behavior and displacement mechanism. PPT has traditionally been used during waterflooding, but due to positive results of heavy oil displacement with CO2 and new GHGs emissions regulations, which provide GHG credits for CO2 usage in EOR and CO2 underground storage, a decision was made to implement PPT during carbon dioxide injection. PPT was also implemented in a group of experiments that covered different WAG processes. In the first group of experiments, Pressure Pulsing Technology was studied during waterflooding with different types of oil with a range of PPT parameters. Also, the impact of PPT on CO2 injections was investigated. In this case, not only PTT properties were the object of study but the impact of gas injection flow rate was researched. Logically following water injection and gas injection with PPT was Water Alternative Gas (WAG) injection with PPT. Several different experiments of the WAG process with PPT were conducted. The goal of the second group of experiments, where the micromodel was used, was to visualize the displacement process in porous media, and to compare fluid flow behavior in the model, with and without implementing PPT.