Crude oil vaporization using carbon dioxide (CO2) is known to have application in oil recovery for highly fractured formations and heterogeneous reservoirs where the major oil content is contained in the non-fractured porosity or isolated oil patches with little associated permeability. Oil vaporization is also the triggering element for formation of miscible front which displaces the oil in CO2 enhanced oil recovery process.
The objective of this experiment was to establish a saturation profile and examine the Pressure-Volume relationship of crude oil in the presence of different CO2 concentrations. The saturation pressure with its Carbon Dioxide concentration is believed to be the required condition necessary for initiating the oil vaporization.
To achieve the above objective a series of experiments were performed to show the oil swelling behavior and obtain the saturation pressure profile and pressure at which vaporization takes place.
The pressure-volume profile of the swelling tests showed that an increase in CO2 concentrations will increase the saturation pressure and cause a dampening on the pressure-volume curve. It also showed that the saturation pressure of the mixture increases according to exponential increase in CO2 concentration.
This study in swelling of crude oil by CO2 will provide an insight into the oil property and behavior as the vaporization takes place, and will provide the explanation on how the misibility is triggered. It will also provide the minimum CO2 requirement to achieve vaporization.