Estudo do processo de injeção de C02 e C1 aplicado a um reservatório de óleo leve

Abstract

The petroleum reservoir hold on its discovery, a self-energy, called primary energy. Therefore, on the beginning of their productive life they are able to produce only with this energy. During the production process, a loss on the reservoir mass occurs, consequently decreasing the ability to produce. In order to reduce the effects caused by this energy loss, it is necessary to use the oil recovery methods. The water and gas injection work to recover the well pressure in order to restore the well productive ability. Nowadays the most wildly use gas is the Carbone dioxin (CO2). This gas can be in high conditions of temperature and pressure miscible with the oil within the reservoir, dislocating it by dissolving itself on it causing the oil to vaporize and inflate. Or immiscible, on low temperature and pressure condition, reducing the oil viscosity and interfacial tension. However, the carbon dioxin can be corrosive when in contact with water. Hence, it is appropriate to study the viability of injecting other kinds of gases. The currently work analysed the injection of CO2 and C1 in a reservoir with characteristics of Brazilian northeast. The C1 was chosen as an injector fluid because it is found on the reservoir needing only to be reinjected. It was analysed for each case, the completion zone, the injection rate e the wells configuration. The chosen configuration was the same for CO2 and C1, and it was the one with peripheral injection, four vertical injector wells, five vertical producers, and two horizontal producer wells. The best injection rate was the 5.000.000 m³/day, injecting completely, until the water zone. The oil recovery factor on the primary recovery was 3,6%. It was possible with the CO2 injection to increase these result to 31,194%. The C1 injection achieved an oil recovery factor of 27.16%, proving its viability.