LAUSR

The reservoirs of volcanic rocks in the Junggar Basin of Xinjiang in China are abundant in reserves with potential for exploration and development. They have the characteristics of high heterogeneity and fracture development. The occurrence of bottom water coning is a serious problem during oilfield development, which leads to a rapid increase in the well water cut and greatly affects the reservoir exploitation. In this paper, a visualized model experiment was carded out to simulate the mechanism of nitrogen injection suppression of bottom water coning, based on full diameter core with developed fracture, using X-ray imaging technology and oilfield tests. The research results show that nitrogen injection has a certain effect on suppressing bottom water coning. Nitrogen can block the high-permeability water flow channel, enter the low-permeability area, and improve fluidic', of the crude oil. The timing of nitrogen injection is the main controlling factor affecting gas injection development. Gas injection after a long-term high water cut period is the main reason for the poor ((MCI of suppression of bottom water coning in the oilfield. When the water cut is relatively low, the bottom water suppression effect is better. When the water cut is 70%-80%, the gas injection effect is the best. Moreover, the greater the nitrogen injection pressure and the longer the soak time, the better will be the effect of the bottom water coning suppression. In this paper, a reasonable development strategy of nitrogen injection to suppress bottom water coning is proposed through an experimental study, which is of great significance for guiding the development of volcanic reservoirs in the oiffield.