Throttle characteristics of multi-stage circumfluence nozzle during the separate-layer injection of CO_(2)  

作　　者：Haizhu Wang Gensheng Li Lichuan Zhao Youwen Wang Yun Liu Qingling Liu Meng Wang Fei Gao Meng Cai 

机构地区：[1]State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102200,China [2]Production Engineering&Research Institute of Daqing Oil Field Company Limited,Daqing 163453,China

出　　处：《Petroleum》2018年第2期187-197,共11页油气（英文）

摘　　要：Separate-layer injection of CO2 is an important method to improve oil and gas production and recovery.Conventional single-stage nozzle is usually blocked by impurities,and the ice-barrier phenomenon is very common.To solve this problem,large-diameter multi-stage circumfluence nozzle was designed to release pressure stage by stage.In order to illuminate the throttle characteristics of the CO2 multi-stage circumfluence nozzles,numerical simulation was performed to test several nozzles with different diameters and stage numbers.Furthermore,we tested the throttle characteristics through laboratory experiments and obtained the effects of several critical parameters such as nozzle diameter,number of stage and pressure drop on the throttle characteristics.The results show that the flow rate decreases as the nozzle stage increases on the condition of constant pressure and nozzle diameter.And pressure difference increases as nozzle stage number increases under the constant flow rate.The throttle capability of multi-stage circumfluence nozzles was much better than the concentric nozzles.Large-diameter multi-stage nozzle is recommended rather than small-diameter single-stage nozzle during the process of separate-layer injection,which can efficiently prevent impurities and ice blocking.The results are expected to provide a theoretical support for the nozzle choice of separate-layer injection of CO2.

关 键 词：Supercritical CO2 Separate-layer gas injection Multi-stage circumfluence nozzle Throttle characteristics Pressure difference 

分 类 号：O35[理学—流体力学]