Impacts of Recompaction on Loose Sandstone Reservoirs

Recompaction in loose sandstone reservoir can cause the variation of reservoir. This study aims to measure how recompaction affect the physical properties and displacement efficiency. Three-dimensional physical simulation experiment was applied to investigate the impacts of recompaction on loose sandstone reservoirs with different three-dimensional physical models. The variation character of physical properties and displacement efficiency was determined. The results show that recompaction can deteriorate the physical properties and affect displacement efficiency. In the area of non-mainstream line between edge and corner wells and formation with obvious pressure reduction, recompaction was relatively strong and remaining oil was more distributed. Formation pressure of basic well pattern decreased obviously and recompaction was strong, which was the main effect of production reduction. After transcription and encryption, well group hydrodynamics was enhanced, water flooding effect was better, and sand production was accompanied. Productivity was maintained or even partially recovered, and influence of recompaction on the reservoir was weakened. For loose sandstone reservoir, water injection should be timely to improve water flooding effect of basic well pattern and keep formation pressure above 85% of initial formation pressure to avoid adverse effects of recompaction on productivity. The research is of great significance for the stable production of loose sandstone reservoir.