Based on the analysis of the formation of the residual oil in the area , combined with the fine geological and multidisciplinary research results, summed up the main types of remaining oil, combined with dynamic and static data, used some measures such as cyclic flooding, fracturing, profile control , to tap the potential of remaining oil, and achieved good results.

This paper mainly studied the influence of starting pressure gradient in CO2flooding. The capillary pressure of low permeability reservoir is much larger than the ordinary reservoir, so that the influence of starting pressure gradient can not be ignored. Since CO2flooding will be widely used in the development of low permeability reservoirs, it is necessary to study the influence of starting pressure gradient. This paper mainly used Runge Kutta Fehlberg Method and Adams Fourth-order Predictor-Corrector to solve the black oil model, which was founded to study the process of CO2flooding. These two methods considered the starting pressure gradient during the CO2flooding, and the influence of reservoir permeability and crude oil density were studied by founding black oil model and use these two methods to solve the model. We have compared the production rate with staring pressure gradient and without starting pressure gradient.

The Characteristics of heavy oil reservoir and the influence factors of edge water invasion are researched though the research of summary of geology in the BQ57 area. 12 factors are confirmed with the orthogonal experiment. The research contains 12 factors,among them, geologic factors contain reservoir heterogeneity, effective thickness, Crude oil properties, angle of bedding and Edge water energy[1]; Development factors contain temperature field, Steam injection intensity, Steam injection time, soak time, Steam injection temperature, Steam dryness, production factor, and it calculates the weight of various factors.

Through thirty years of development, Lianhua oil reservoir has entered into the stage of low-speed development. At present, the rate of oil production is only 0.0033%. Firstly, it divided development stage of Lianhua reservoir and analyzed production characteristics of each stage. By mean of the production decline curve, it predicted the recovery of the reservoir to estimate the ultimate recoverable reserves and the recovery percent. The results show that the ultimate recoverable reserves of Lianhua reservoir was about 50.813×104 t, the ultimate recovery was 13.177%, the recovery percent of recoverable reserves had reached up to 95.094%, and the remaining recoverable reserves were rare. Therefore, it urgently needs to find a more reasonable development model to do secondary development of Lianhua reservoir. The conclusions have an important realistic significance of guiding secondary development of the Lianhua reservoir.