ENHANCED OIL RECOVERY IN HEAVY OIL RESERVOIRS

The study conducted steam flooding experiments utilizing cylindrical cores of diverse sizes and containers, focusing on the recuperation of crude oils labeled A to E. Various core attributes, dimensions, and seals were utilized, as summarized in Table 4.1. The test oils, including distilled oil blends, underwent characterization based on API gravity, viscosity, specific gravity, boiling points, refractive index, and distilled percentages under steam conditions, outlined in Table 4.2. The obtained results were divided into three categories. The initial set, presented in Tables 4.3 and 4.4, showcased enhanced oil recovery through steam injection, demonstrating independence from initial water and oil saturations. Recovery factors (RF) were computed using the formula RF = (initial oil - oil recovered) / initial oil × 100. The second set of tests, delineated in Tables 4.5 and 4.6, sought to comprehend the mechanisms contributing to higher recoveries with steam injection, considering factors such as viscosity reduction and thermal expansion of oil. The third set (Table 4.7) encompassed experiments involving high-pressure steam injection. The recovery prediction employed the Buckley-Leverett equation for a radial system, incorporating considerations of steam zone expansion and variations in water density. The study explored the recovery mechanism, emphasizing the impact of viscosity reduction and thermal expansion in achieving enhanced recoveries during hot water and steam drives. Major findings highlighted the efficacy of steam injection in achieving substantial recovery rates, ranging from 75 to 90% of the initial oil in place. Temperature emerged as a critical factor influencing oil viscosity and, consequently, recovery. The experimental data underscored the superiority of steam over water floods in attaining heightened ultimate recoveries from core samples. The outcomes indicate that steam flooding presents a promising avenue for enhanced oil recovery. The study offers valuable insights into the underlying mechanisms and influential factors associated with this method.