Physical Simulation about Sandbody Physical Property Control on Forming Lithological Reservoirs

Taking the lithological reservoir of Dongying sag as an example, this paper discusses how the change of physical property of sandbody controls the increase of oil saturation from geological analysis, physical simulation experiment and reservoir-formation mechanism. The petroliferous property of the sandbody enveloped by effective source rock Lower Tertiary is superior to that of the sandbody that lies outside the source rock. And the oil saturation of sandbody enveloped by source rock is inclined to increase when the physical property of sandbody becomes better. Based on the analysis on the lithological reservoir of Dongying sag, physical simulation experiments on controlling the forming of lithological sandbody were conducted with hydrocarbon migration and accumulation simulation facilities. The results show that the resistivity of sandbody changes quickly with the increase of grain size, in other words, the speed of the sandbody's reaching a certain oil saturation becomes faster, which indicates that a better physical property of sandbody is conductive to forming lithological reservoir since the physical property is one of the important factors influencing the reservoir forming of sandbody.