Optimization of gas injection

The first part of the parametric study investigates how the position and size of the injection well can influence the results.

Two positions are tested, on the bottom and lateral  wall of the domain, with an intlet lenght constant equals to 0.025m. Then the size of the inlet is reduced by two as it is shown in the pictures below:

Simulation parameters are listed in the table below:

  Velocity Inlet  Percentage of gaz injection  Percentage of oil recovered
Inlet 1  0,6 m/s 75% 68,5%
Inlet 2 0,6 m/s 75% 77%
inlet 3 1,2 m/s 75% 66%

The graph below represents the percentage of oil in the domain in function of time. We can observe that after injecting 70% of gas in the domain, the quantity of oil remains constant: the oil recovery ratio is maximum. There is a maximum quantity of gas injected after which oil viscosity ratio can not be increased.

After an injection of 75% of nitrogen, the same amount of oil is recovered in the case of Inlet 1 and 3 . Therefore, the size of the injection well does not  influence the oil recovery ratio.

On the contrary, the percentage of oil recovered by Inlet 2 is increase by 12.6% compared to Inlet 1. The position of Inlet 2 is more efficient than the position of Inlet 1 to recover oil. Thereforethe position of the injection well have an impact on the oil recovery ratio.

We recommand to investigate carefuly the position of the injection well before developping the nitrogen injection recovery method in the Tarim Basin, as it impacts the oil viscosity ratio.