Sensitivity Study of CO2 Huff & Puff Jatibarang Using Compositional Simulator

Abstract

The CO2 injection has been applied in the petroleum industry, miscible and immiscible CO2 flooding are the processes for many EOR methods projects. Huff & Puff simulation approach has been developed to evaluate oil recovery mechanism for CO2 injection process and to find an incremental production using this process for oil reservoir. These recovery mechanisms include CO2 impurity effect, swelling effects, relative permeability effects, viscosity reduction, miscibility effects, and gas solubility.
Huff & Puff CO2 consist of three steps: injected CO2 into production well, soaking the well and the well is opened for production. A soaking time period has a different time in every projects, depends on characterization of reservoir, sensitivity of soaking time and total CO2injected will be simulated to carry out the optimum days for soaking time period and to get optimum incremental oil from reservoir.
Jatibarang Field is chosen to apply Huff-n-Puff CO2 injection due to its oil characteristic and having CO2 source nearby. Jatibarang field is located about 30 KM southwest of Cirebon city within the Pertamina EP concession area, discovered in November 1969. Jatibarang Layer F began to be produced in March 1975. The F layer consists of carbonate rock and shale which deposited in continental shelf platform or reefal environment, and the thickness of the reservoir is 4-5 m. Jatibarang reservoir has API 36, 0.5-0.9 cP of viscosities, 10.87-21.38% of porosities, 3727-3937 feet of reservoir depth and permeabilities ranging from 40 to 60 mD. With these reservoir properties, the EOR screening shows that CO2 EOR was suited to be applied in Jatibarang.
This reservoir simulation study is very useful for evaluating the effect of CO2 injection and parametric analysis of reservoir data and injection operation.