Effect of rock stress sensitivity on steam flooding in unconsolidated sandstone heavy oil reservoir——by taking BZA oilfield as an example

In order to solve the problem that rock deformation will affect the development effect in the process of steam flooding in heavy oil reservoir, the rock stress sensitivity experiment is proposed for the first time in unconsolidated sandstone heavy oil reservoir, and the physical simulation experiment research on the influence of rock stress sensitivity on steam displacement efficiency was carried out. The results of the study show that: whether it is a high-permeability reservoir or a low-permeability reservoir, the permeability gradually decreases with the increase of effective overburden, the sensitivity of the high-permeability reservoir is weaker than that of the low-permeability reservoir, and the change in permeability is irreversible. The higher the effective overburden pressure, the heavier the core is subjected to compression, the more serious the porestructure changes, and the lower the oil displacement efficiency. The stress sensitivity of rock has a great influence on the development effect of steam flooding. The research results have a certain guiding role for steam flooding development and strategy formulation in later heavy oil reservoirs.