Production mechanism of diluent injection in heavy oil and bitumen

The invention of horizontal and hydraulic fractured have shaped the oil and gas industry in such a way that engineers could never imagine. Thanks to the new technology, tight formation productions help the United States comes tantalizingly close to energy independent. After four decades, the U.S lifted the ban on crude oil export increased the competition in the energy market. However, tight formations productions require high capital investment, and high water consumption but its production declines fast. Scientist have been actively seeking for alternative resources for future supply. Heavy oil and bitumen is one of interesting alternative, as the resource can be all over the world, but the largest reserves are concentrated in Americas: Venezuela, and in Canada’s Alberta Province. The production of heavy oil and bitumen is an extremely energy-intensive activity with the associated high environmental impact. Most common methods for heavy oil and bitumen production are surface mining or heat injection. The heat lost associated with steam injection is a big concern, sometimes it can be as high as 90%. To reduce heat loss, the use of solvent was employed. However, solvent processes with vertical wells could be much slower than the thermal process such as steam injection. Since the introduction of horizontal well and hydraulic fracture that helps increase the contact area between the solvent and oil, the investigation of solvent injection process has been widely revisited. Solvent or diluent injection without understanding asphaltene behavior can cause permeability and porosity reduction. In this study, I have investigated the mass transfer mechanisms in diluent processes with focus on understanding how these mechanisms govern asphaltene precipitation, flocculation and transportation.