In order to study the interlayer interference mechanism of water drive reservoir, the development plan of multi⁃layer co⁃production is developed. The core hole and permeability data of Gaotaizi core in the western Daqing central region are statistically analyzed, and the four⁃pipe parallel constant pressure displacement experiment is carried out with artificial cores with different permeability. The effects of injection and production pressure difference and permeability grade difference on recovery and water cut are studied. It is found that there is a reasonable injection⁃production pressure difference in core co⁃production with different permeability. The larger the permeability gradient is, the smaller the overall recovery is. The influence rule of permeability difference on interlayer disturbance is clarified from the mechanism, which provides theoretical basis for subdivision adjustment and water quantity adjustment.

The technology of water plugging in the oil well is more and more concerned with its low cost, low damage and long period of validity. But in the application, it is found that the effect of water shutoff and profile control of active crude oil in different blocks is quite different. Plugging measures effect is obvious in some fields, while in the others, it is very poor. The reason is that the content of gum and asphaltene in crude oil components of different blocks is quite different, and this substance will have a great influence on the emulsification effect of active crude oil. In order to improve the level of active⁃crude⁃oil water plugging technology fundamentally, on the basis of extensive investigation and research, the influence factors of emulsifier structures and crude oil composition on oil⁃in⁃water emulsion are studied, through the laboratory emulsification experiment and spectral analysis. It is concluded that the longer the length of the oil⁃wet carbon⁃carbon single chain of the Span series of emulsifier, the greater the viscosity of the emulsion. The existence of double bond is not conducive to the formation of emulsion and the emulsion viscosity is low. The composition of 5 aromatic rings in the gum is conducive to the dissolution of asphaltenes, while the planar arrangement of 5 aromatic rings will increase the viscosity of the emulsion.

The development of low permeable reservoir by means of alternate water gas injection can not only enlarge the swept volume, supplement formation energy, but also effectively prevent gas channeling. However, the problem of plug in gas well often occurs during the construction. By simulating the distribution of internal pressure and temperature in the wellbore of the gas injection well, the cause of freezing and plugging is analyzed. The main reason is the long time shut in of the gas injection well, resulting in the formation of fluid flowing back to the frozen plugging section and the CO ₂ reaction in the wellbore to form a frozen plug. Therefore, the well test method is used to calculate the pressure change rule in the wellbore after closing the well, and the time of formation fluid to freeze plugging is obtained. The results show that the gas injection rate has great influence on the wellbore temperature field distribution. As the injection speed increases, the low temperature in the wellbore extends longer. The phase state of CO ₂ gas can change within 1 000 m of the wellbore, which causes low temperature and high pressure in the wellbore and makes hydrate easily. Finally the limit closure time of injection well is determined to be 25 d according to the law of oil and gas twophase seepage and the law of pressure change after well closure.