Optimization of huff-n-puff gas injection in shale oil reservoirs

The numerical simulation results and discussions show that the optimum huff time is so long that the pressure near the wellbore reaches the set maximum injection pressure during the huff period; and the optimum puff time is the time required for the pressure near the wellbore to reach the set minimum production pressure during the puff period. The benefits of soaking may not compensate the loss in injection and production due to the time lost in the soaking period. Therefore, soaking may not be necessary during the huff-n-puff gas injection in shale oil reservoirs. The number of huff-n-puff cycles is determined when an economic rate cut-off is reached.