Study On Design Of Ground Facilities For Scale Nitrogen Flooding In Tahe Oilfield

After 20 years of sustained and efficient development,the recovery rate of each block in Tahe oilfield has gradually declined.Gas injection to improve the recovery rate has become the development trend and goal in the middle and later stages of the oilfield.However,there is no in-depth study on gas injection in ultra-deep wells in China.The research and application of large-scale nitrogen drive can provide technical support for gas injection optimization and overall recovery improvement of carbonate reservoirs in Tahe Oilfield.Taking Block 4 of Tahe Oilfield as the research object,gas injection indexes such as gas injection volume and nitrogen concentration parameters are determined according to its field requirements.Through the analysis of different nitrogen production technologies,the traditional single column reflux cryogenic nitrogen production process suitable for block 4 of Tahe oilfield was selected,and the process was simulated by using HYSYS model,and efficient distillation column and precooling unit were selected.In order to improve efficiency and reduce energy consumption,the process flow of nitrogen production was optimized.Finally,according to the existing nitrogen injection process in China and the site conditions of block 4 in Tahe oilfield,two sets of surface nitrogen injection schemes are designed and compared.The combination of nitrogen production and nitrogen injection forms a large-scale surface engineering scheme of nitrogen gas drive.