The researchers studied how pressure affects the flow of fluids in rocks. They found that as pressure increases, the rocks become less porous and less permeable, meaning it's harder for fluids to move through them. This can lead to errors when predicting how oil or water will flow in a reservoir. The researchers used experiments on rock samples to show that as pressure goes up, the amount of water and oil that can be trapped in the rocks also increases. They also found that oil's ability to flow through the rocks decreases with higher pressure, while water's ability to flow stays about the same.