Publications

Miscible gas injection in a watezflooded feservoir allows additional oil recovery. Dispersed trapped oil displacement by miscible gas injection is a complex process, as an attempt to understand the basic phenomena and to select the main parameter affecting this Tertiary recovery method, the laboratory studies under reservoir conditions and by using actual rocks and or synthetic fluids are necessary. This' paper presents the laboratory study of the above problem where the displacement mechanism is described and discussed. The influence of different parameters on the oil bank formation and on displacement efficiency is established.The important role of the mass transfer is pointed out. However, its quantitative value could only be estimated from an everage trapped oil swelling factor. It was thus necessary to measure the molecular diffusivity between the oil and miscible gas in static conditions and under reservoir pressure temperature.As a first step, the measurement and the interpretation method has been established by using C1 - C10 as fluids under constant mass conditions. Our experiment results are compared to all published data in the literature.As a second step, thls method was extended to multicomponent liquid system by using a Ternary synthetic oil C1 C4 CIO mixture and pure methane as the injected gas. Finally, the effect of the porous media on the molecular diffusivity was systematically studied by using C 1 C 10 system.The mass transfer phenomena between trapped oil and the injected gas in the presence of water are even more complex. That is why, each reservoir beingh specific case, an individual experimental study is required.