Manifestation of nonlinear filtration effects in low permeablimitility reservoirs at variable modes of well functioning

V. Sh. Shagapov ; O. V. Dudareva

Vestnik Tomskogo gosudarstvennogo universiteta. Matematika i mehanika, no. 1 (2016), pp. 102-114

Résumé

According to the earlier theoretical model of filtration with a limiting gradient of pressure, indicator dependencies under variable modes of well-functioning are studied. On the basis of numerical simulation of the well operation, the possibility of revealing non-linear effects of the filtration law under the reservoir conditions is analyzed. For example, considering the curves of well production redistribution during transient conditions of the well operation, one can identify possible non-linear effects of filtration and see the manifestation of the limiting pressure gradient q. The presence of the limiting pressure gradient significantly affects the nature of the filtering process. The manifestation of the limiting pressure gradient q can be seen by the intensity of the well production rate decrease with time. When the filtration occurs by the linear law, the intensity of the flow rate decrease is insignificant and, to a due time, takes a constant value. Due to the manifestation of nonlinear filtering effects, a decrease in the fluid production rate of the well is observed as compared to the case of the linear Darcy law. It is found that the enhanced oil recovery occurs with a decrease in the limiting pressure gradient q and with an increase in the power exponent.

Détail

Keywords: nonlinear filtration, ultralow permeability, limiting gradient of pressure, oil recovery of layers, finite difference method.