⦁ Short answers (3 pts each)
⦁ Please define instantaneous gas oil ratio
⦁ Please define the production gas oil ratio
⦁ Please briefly specify the procedure to adjust oil saturations for water drive reservoirs.
⦁ (10 pts) Please plot the solution gas oil ratio and instantaneous gas oil ratio with pressure relations, and explain the changes alone the instantaneous GOR plot.
⦁ (15 pts) A saturated oil reservoir has a bubble point pressure of 2100 psi at 175F. The initial reservoir pressure is 2400 psi, original oil in place is 10 MMSTB, connate water saturation is 15%, porosity is 20%, cw=3.2*10-6 1/psi, cf=3.1*10-6 1/psi. The PVT data is listed in table 1 and relative permeability information is listed in table 2. Please calculate the following:
⦁ The oil compressibility at different pressure using oil formation volume factors
⦁ Cumulative oil and gas production when pressure decreases to 2100 psi, 1800 psi, and 1500 psi.
Table 1. Reservoir PVT Data
Table 2. Relative permeability with liquid (oil and water) saturation