Due to the strong stress sensitivity and threshold pressure gradient of the tight oil reservoir in Jimsar, Xinjiang, the current nonlinear seepage model cannot reflect the seepage characteristics of the tight reservoirs. Therefore, based on the physical simulation experiment of indoor core flooding, a new nonlinear seepage model of compact reservoir considering threshold pressure gradient and stress sensitivity is established, and the pressure gradient utilization map is drawn according to the model. The results show that the threshold pressure gradient of the tight reservoir has logarithmic relationship with permeability. The error between the seepage characteristic curve of the new model and the actual seepage characteristic curve of the reservoir is less than 5.00%, which can truly reflect the actual seepage characteristics of the reservoir. The higher the permeability, the higher the pressure gradient utilization rate (N), the less the pressure loss. With the pressure gradient increases, N increases logarithmically. Therefore, in order to improve the effective utilization of the tight reservoir pressure gradient, it is necessary to increase the production pressure difference, and take acidizing and fracturing measures to improve the reservoir permeability.

Using waxy crude oil and pure water as the working material, several groups of W/O emulsions with different microscopic droplet distributions were prepared. With microscope and focused beam reflectance measurement instrument, the size and distribution of the dispersed droplets in emulsion were observed and measured. Furthermore, the effect of droplet distribution on the rheology and wax precipitation characteristics of emulsion was discussed. The results show that with the increase of water content, the apparent viscosity of W/O emulsion will be higher, the yield stress, gel point and wax appearance temperature will also increase, while the constant stress will show a gradually decreasing trendency. The phase transition point of Daqing waxy crude oil is about 60% water content.