Abstract: In numerical simulation research, the more factors considered, the higher the accuracy of single-well fitting, and the model can better approximate the real geological conditions. In order to solve the problems of low fitting accuracy of single wells and unclear understanding of remaining oil in Bohai M Oilfield due to the influence of strike-slip faults, large formation dip angles, and unclear characterization of single-layer viscosity differences in the numerical simulation process. Based on the gas logging data of Bohai M Oilfield, the relationship between gas logging data and crude oil API degree and the relationship between API degree and viscosity are established through data regression. Based on the above relationships, a planar fluid model is obtained by using Petrel modeling software to perform well interpolation, constrained by well depth, faults and oil-water interfaces. The planar fluid models of each layer are modeled and assigned values to obtain the three-dimensional fluid model of Bohai M Oilfield. The application results show that the three-dimensional fluid model is excellent on the water content of a single well in Bohai M Oilfield after loading. The overall formation viscosity of the oilfield in the model conforms to the recognized geological laws, and the remaining oil in the oilfield is finely characterized. This research method has reference significance for improving the numerical simulation accuracy of high dip angle oilfields and tapping the remaining oil for subsequent adjustment wells.