Grid upscaling is to keep the reservoir physical properties and seepage characteristics of the two models as same as possible before and after upscaling. Thus, the model after upscaling can achieve the same development effect as before upscaling. The permeability is upscaled by harmonic average and arithmetic average. It's found that the relationship curve between recovery degree and water cut after upscaling is different from that before upscaling. Based on reservoir engineering theory, a functional relationship between slope and intercept of Kro/Krw⁃Sw relationship curve and slope and intercept of water⁃oil ratio and recovery relationship curve is derived. Therefore, the phase permeability curve after upscaling can be deduced back. It's found that there is a linear relationship between the displacement distance of the phase permeability curve and the intercept of the fitting line of the water⁃oil ratio curve and the recovery degree curve. The displacement distance of the phase permeability curve can be calculated. The phase translation law is verified by using actual oilfield data. The error of water⁃oil ratio and recovery degree curve between after translation and before coarsening is 3.16%, and the precision is high.

At present, due to active edge water in BQ57 area of target oilfield, the reserve recovery is low. Therefore, it is necessary to study the remaining oil in BQ57 area to ensure good results in thermal recovery process. The distribution law of remaining oil in vertical and plane of layers III 1 and 3 in BQ57 area is studied. The total remaining oil is 43.22 ×104 t. In the vertical, the geologic reserve of layer Ⅲ11 is 17.76×104 t. The remaining geological reserves are 14.72×104 t. The degree of reserve recovery is 17.19%. The geological reserve of layer III12 is the smallest, which is 5.79×104 t. The remaining oil is also less, which is 4.86×104 t. The degree of reserve recovery is 16.09%. The remaining oil in layer III31 is the largest, which is 15.4×104 t. The degree of reserve recovery is 11.20%. The remaining oil in layer III32 is 8.26 ×104 t and the degree of reserve recovery is 6.17%. On the plane, the proportion of remaining geological reserves channel is 52.87% in underwater distributary. Because its distribution area is largest, the proportion of remaining oil is the highest and the value of reserves abundance is the highest. The proportion of remaining oil in front sand sheet is 44.98%. Its value of reserves abundance is also higher. The latter adjustment of well pattern needs to be combined with the productivity potential of a single well, the underwater distributary channel and front sand sheet should be given priority in the adjustment of well pattern.

After the XQ⁃45 block entering the multiple rounds of steam huff and puff, it is affected by edge water, faults, reservoir properties and other factors. The remaining oil distribution is complex, and steam huff and puff effect is getting worse. According to the reservoir dynamic data, the 79 wells in this block are divided into different types of heavy oil wells according to the remaining oil saturation parameters. Among them, the number of remaining oil wells affected by edge water is more than 22. As the edge water proceeds along the high⁃permeability layer to the oil well, the water content rises quickly and easily causes flooding. To further improve the effect of steam huff and puff, aim at the unutilized section in the edge water affected oil well, and take the single⁃layer steam huff and puff mode to study the optimization of steam huff and puff parameters affected by edge water. Through extract single⁃well geological model and compare different steam injection programs, the best program is selected: steam injection volume is 100 t/m, the oil steam ratio maintain at 0.2 t/t or more, obtain the maximum amount of oil production. The results show that cycle steam injection volume is 100 t/m, the oil production is the largest in the third cycle, and the sweep radius of steam reaches the maximum. After 5 rounds of steam huff and puff, cumulative steam injection volume is 3 700 t, cumulative liquid production is 4 500 t, cumulative oil production is 738.65 t, and the program implementation effect is getting better.

Downhole oilwater separation technology can make production liquid divide into water and oil, reduce the surface water treatment and improve oil displacement efficiency. However, pressure difference between output layer and injection layer increases after implementation of this technology. When pressure difference is greater than threshold pressure gradient of interlayer, the interlayer fluid flows. In order to prevent the occurrence of interlayer channeling, numerical model of injectionproduction well is established according to actual formation parameters. After studying the injection and production technology of the same well, the range of cross flow and the upper limit of daily production of single well are obtained, and the limit chart of permeability, thickness and single well production is obtained. When daily production volume of single well is 70 m3 and interlayer permeability is 1×10-3 μm2, the lower limit of interlayer thickness is 2.3 m; When daily production volume of single well is 70 m3 and interlayer thickness is 3 m, the upper limit of interlayer permeability is 1.25×10-3 μm2. When the physical parameters of interlayer are changed, daily production volume of single well can be determined according to the plate, which can be used to guide the development of oilfield development plan.