Experimental Study on Distribution of Residual Oil after Surfactant/ Polymer Flooding with Resistivity Method and Influence Factors

Residual oil distribution is an important factor for evaluating the oilfield development effects and determining the enhanced oil recovery methods. In physical modeling experiments, the residual oil distribution and its change are often detected through oil and water resistivity and their variation in the cores. Guided by the theories of modem reservoir engineering, enhanced oil recovery and modem detection technology, through optimization of electrode material and configuration of electrodes, experimental study has been conducted on the factors affecting calibration curve, and the influence of the way by which the oil is saturated in 3D simulation models on initial oil saturation and residual oil distribution after SP flooding. The study results show that mineralization of experimental water, ion type and permeability difference have great influence on calibration curve; For 3D simulation model cores, saturating oil in the corner and polymer/surfactant flooding are recommended; For vertical heterogeneous reservoirs, residual oils distributed mainly in moderate and low permeability layers, and distributed mainly in the two sides of structures which are far away from injection wells and main stream lines.