| Abstract: | ![]()
The problem of calculating regions of residual viscoplastic oil with a critical pressure gradient is considered. This problem has hitherto been solved mainly for uniform strata (see, for example, [1–3]) but in the present paper, which follows the work of Entov, Pankov, and Pan'ko [4], the problem is considered not only for uniform strata but also for layered strata and vertically nonuniform strata. It is shown that for sufficiently thin strata allowing free flow between individual seams the formulation of the problem is the same for the piston model and the Buckley-Leverett model and reduces to a two-dimensional boundary value problem with a continuous nonlinear effective flow law for the water. An approximate numerical method of calculating regions of residual oil that is suitable for the three listed types of strata is described and illustrated by examples. |
