Among the several mechanisms of producing an oil reservoir, the gas expansion
mechanism is an important primary recovery process. During the depletion of the reservoir,
the pore pressure may reach values below the bubble pressure of the oil, allowing the gas
release. From the geomechanical point of view, the change in pore volume, due to production,
changes the dynamics of gas generation, since it is dependent upon the change in pore
pressure. Studies considering the fluid-mechanical coupling show the relationship between
variations of fluid pressure and porous structure of the reservoir. This work aims to study the
influence of the fluid-mechanical partial coupling (one and two-way) in the process of gas
release during recovery of hydrocarbon. It was used the partial coupling methodology
developed by ATHENA/GTEP – PUC-Rio. The model called “A” has only one producing
well, while the model called “B” has four injection wells, besides the producer. Initially, the
oil present in the reservoir is in undersaturated condition. In model “A” was observed that the
pressure drop of fluid is more accentuated, until it reaches the bubble pressure, when
considering the two-way coupling. Consequently, the gas release initiation occurs earlier than
one-way coupling scheme. After starting gas generation, the rates of pressure change in both
partial coupling scenarios tend to equalize. In terms of compaction and subsidence, it was
observed most significant displacements values in two-way coupling, highlighting the
rigorous consideration of the geomechanical effects in the applied methodology. In model
“B”, it was observed that the consideration of the two-way coupling resulted in a recovery
scenario without generation of gas, unlike the results shown by the one-way coupling in
which gas was generated during 40% of total simulation time. In geomechanical terms it was
observed, as presented previously, that the values of vertical displacement were greater in the
two-way coupling. The methodology used in this paper proved to be capable of simulating
coupled process in a blackoil reservoir, as could be observed by the results. Furthermore, the
use of one-way partial coupling scheme, which is widely used in the oil industry, showed
results quite different in terms of gas liberation, when are compared with the two-way partial
coupling scheme, which was developed in a more rigorous way
