A pressure vs. Volume analysis was done to determine the bubble points for Oil A, Oil B and water, with CO2
Oil A
Represented in Fig. 7 below, the Pressure vs. Volume behavior of Oil A is displayed, the graph is separated into two different sections as Oil A transitions from a single phase fluid to a two phase fluid, the transition occurs at 800 psi which represents the bubble point for Oil A. Fig XX. Pressure vs. Volume Oil A
Analysis was done on the relationship between compressibility of oil vs. pressure. As shown in the figure below, compressibility increases linearly as pressure decreases from 2500psi to the bubble point. At the bubble point, as pressure decreases now the compressibility increases exponentially. The change in gradient occurs as there is gas present in the fluid. Fig XX. …show more content…
) and one below the bubble point was used. As shown in the figure, above the bubble point as pressure increases Bo decreases. Below the bubble point, as pressure increases toward the bubble point, so does formation volume factor although with a higher gradient than compared to the one below the bubble point. Fig XX. Pressure vs. Rs and Bo Oil A
Oil B
In the figure below, the Pressure vs. Volume for Oil B is presented. Along with Oil A, volume increases linearly as pressure decreases. The two relationships appear to be similar, although with different gradients. The bubble point as displayed in the figure below occurs at 200psi. Fig XX. Pressure vs. Volume Oil B
Using Eq. 3, the compressibility of Oil B was calculated against pressure as shown in the figure below. Compressibility above the bubble point increases with decreasing pressure, although difficult to interpret as the gradient is very small. At 200psi, compressibility jumps suddenly, indicating the change in gradient. Reason being the bubble point was not reached until the pressure was reduced from 2500psi to