No abstract

Light leakage mechanism of curved ADS mode LCDs was studied by simulation and experiments； it was founded that the glass got an optical retardation because upper/bottom glass of the panel got a residual stress, under the effect of the stress optical coefficient, and then combining with LC layer's optical retardation, the light leakage occurred under cross polarizer. In this paper, simulation and experimental result was compared, and was proven to be perfect similar.

Spontaneous water imbibition is an important mechanism in water-wet fractured reservoirs. For volume-fractured reservoirs, to evaluate the oil productivity and oil recovery through water counter-current imbibition, we propose an analytical method for optimizing the reservoir volume fracturing scheme. Based on the two-phase fluid flow differential equation for capillary force, a three-dimensional water imbibition productivity equation is derived analytically. The equation for the water imbibition productivity considering the fracture network is obtained. A numerical model is constructed to verify the validity of the average capillary diffusivity coefficient and the results of the analytical model. By applying this method to a low permeability reservoir, after volume fracturing and waterflooding huff and puff, the relationship between the tenth year’s oil recovery and oil production rate and the length, width, and density of the fracture network is predicted, which gives an optimization of the field fracturing construction scale. The results show that the length and width of the fracture network should be no less than 50% of the well spacing and row spacing to obtain a reasonable production. Considering the fracturing technique and economic feasibility, the higher the density of the fracture network, the better the production obtained. Through hydraulic volume fracturing and waterflooding huff and puff, water imbibition is brought into full play and the 10 year oil recovery is increased by 6%–8% in this area.

In the fracturing, injection and production of unconventional tight reservoirs, the change of fluid pressure will cause significant changes in effective stress, which will greatly affect the dynamic characteristics of the reservoir. On the basis of the adaptive seepage numerical simulation method for different scale medium of tight oil in the early stage, through the study of the deformation mechanism and deformation law of natural / artificial fractures and matrix pores during the whole life cycle including hydraulic fracturing, production and fluid injection to supplement energy, the dynamic variation models of multi medium geometry, physical properties, conductivity and well index are established, and the multi medium fluid solid coupling dynamic simulation technology is formed. The integrated dynamic simulation of multi-media complex seepage and hydro-mechanical coupling is realized.

An analytical model has been developed for quantitative evaluation of vertical sweep efficiency based on heterogeneous multilayer reservoirs. By applying the Buckley-Leverett displacement mechanism, a theoretical relationship is deduced to describe dynamic changes of the front of water injection, water saturation of producing well, and swept volume during waterflooding under the condition of constant pressure, which substitutes for the condition of constant rate in the traditional way. Then, this method of calculating sweep efficiency is applied from single layer to multilayers, which can be used to accurately calculate the sweep efficiency of heterogeneous reservoirs and evaluate the degree of waterflooding in multilayer reservoirs. In the case study, the water frontal position, water cut, volumetric sweep efficiency, and oil recovery are compared between commingled injection and zonal injection by applying the derived equations. The results are verified by numerical simulators, respectively. It is shown that zonal injection works better than commingled injection in respect of sweep efficiency and oil recovery and has a longer period of water free production.