Effect of Improvement of Temperature and Gas Amount on Nitrogen Flooding

Abstract

Oil and natural gas are energy resources with high demand, so it is very important to implement enhanced oil recovery technology in old fields to obtain optimum oil production. The enhanced oil recovery technology that will be discussed on this occasion is more specifically related to the gas flooding method, namely nitrogen flooding. Nitrogen flooding is currently used more often as an alternative to CO2 flooding. However, the limitation of this method is that it is only effective when used in a field with a high depth, because it requires a constant high pressure and temperature so that this gas can dissolve into the reservoir fluid. Therefore, it is necessary to conduct a more in-depth study of the nitrogen flooding method, so that its application can get optimal, efficient, and economical results. The results of laboratory research were carried out to study the displacement of crude oil using the high pressure nitrogen injection method. It aims to study the effect of temperature and GOR on crude oil recovery and the solubility process in high pressure nitrogen injection. In addition, the effectiveness of nitrogen injection after water flooding, and the effect of propane slug driven by nitrogen injection were also analyzed. There are nine types of experiments carried out using crude oil 42.3° API which is recombined with natural gas. This experiment used two temperatures, 70° F and 120° F, and three GORs, namely 575 scf/stb, 400 scf/stb, and 200 scf/stb. The reservoir model used was a stainless steel tube 125 feet long and 0.435 inches in diameter, packed with consolidated sand to provide an average permeability of 910 mD. The recovery factor in nitrogen injection is influenced by the gas content in the system. If the gas content is high, then nitrogen injection will result in a higher oil recovery compared to conditions where the gas content is low.