Perpustakaan Digital ITB

CO2 Huff-n-Puff is a method of increasing oil recovery, which is widely used around the world. It has been proven to be one of the most effective and profitable method to increase oil recovery from mature oil field. CO2 Huff-n-Puff is done in one single well. This method is conducted by shutting a production well, then injecting certain amount of CO2 into the well. After being injected with CO2, the well is shut again for some amount of soaking time, to let CO2 soak the productive area around the well and dissolve into the oil. When the soaking time period is over, this well is being reopened to enter production phase again. CO2 mainly works to reduce oil viscosity and cause oil swelling. Yet the effect of CO2 in reservoir and the oil itself may vary, depends on the reservoir and fluid properties, and the injection technique. Some of the most essential parameters to the effectiveness of CO2 Huff-n-Puff are reservoir permeability, fluid composition, injection rate, injection time, injection volume, and also soaking time. Thus, a sensitivity analysis needs to be done to determine the best injection scenario for a certain reservoir and fluid properties. One of the most important thing that needs to be accounted for CO2 Huff-n-Puff method is the economic aspects. As well as any other project in oil and gas industry, before applying CO2 Huff-n-Puff in real field, an economical analysis should be conducted to determine if the injection scenarios are economical or not. This analysis is very important to forecast revenue after injection is done, especially during this era, when oil price is no longer as high as it used to be (Bondor, 1993). In order to foresee how CO2 will affect the oil production, reservoir simulation needs to be executed. By doing simulation, the most effective and suitable Huff-n-Puff scenario under certain constraints can be determined. In this study, sensitivity and economical analysis are done to determine the best CO2 Huff-n-Puff injection scenario, not only from technical aspect, but also from economical aspect. This study concludes that the technically-best case is also the economically-best case, which includes injection of CO2 at 3.85 MMSFD for 14 days, followed by 7 days of soaking time. But this economically-best case is still not more profitable than the base case (in which the well does not receive CO2 Huff-n-Puff treatment).