基于数值模拟的分层注气气嘴节流压降敏感性分析OA
Sensitivity Analysis of Throttling Pressure Drop for Layered Gas Injection Nozzles Based on Numerical Simulation
为解决含 CO2 天然气分层注气井气嘴节流压降敏感性分析不足、井下气嘴选型与分层流量调配难度大的问题,结合深海复杂井况工程需求,本文以含CO2 天然气分层注气气嘴为研究对象,基于Fluent数值模拟平台,构建包含能量方程、质量方程、动量方程、多组分输运模型及标准 k-ε 湍流模型的数值计算体系,采用控制变量法,研究了 CO2 摩尔比例、气嘴口径、流量、温度、出口压力及多因素耦合作用对气嘴节流压降的影响,揭示了气嘴内部压力分布规律,并在南海某采油平台开展现场试验.研究结果表明:①气嘴节流压降主要集中于气嘴收缩区域,CO2 摩尔比例为 20%～80%时,节流压降随 CO2 含量升高呈二次函数降低,其中,CO2 摩尔比例为 20%～50%时,压降变化更显著;②单一因素作用下,节流压降随流量增大呈二次函数增大,随温度升高线性增大,随气嘴口径与出口压力升高逐步降低;③流量—温度耦合作用时,流量主导压降上升,温度降低可小幅抵消压降增幅,出口压力—温度耦合作用时,二者协同增强压降抑制作用;④现场试验选用 5.2 mm 口径气嘴,实际井口注气压力较目标压力高 0.6 MPa,实际注入流量(7.2×104 m3/d)与目标注入流量(6.1×104 m3/d)误差小于 20%,满足现场分层注气调配要求.本文对多因素及耦合作用下含 CO2 天然气气嘴节流压降变化规律进行研究,可为含 CO2 分层注气井井下气嘴精准选型、分层注气流量动态调控提供可靠理论与技术支撑.
To address the problems of insufficient sensitivity analysis on the throttling pressure drop of gas nozzles,great difficulties in downhole gas nozzle selection and layered flow rate allocation in layered gas injection wells with CO2-bearing natural gas,and to meet the engineering demands of complex deep-sea well conditions,this paper takes the layered gas injection gas nozzles for CO2-bearing natural gas as the research object.Based on the Fluent numerical simulation platform,a numerical calculation system including the energy equation,mass equation,momentum equation,multi-component transport model and standard k-ε turbulence model is established.Using the control variable method,this paper investigates the effects of CO2 molar ratio,gas nozzle diameter,flow rate,temperature,outlet pressure and multi-factor coupling on the throttling pressure drop of gas nozzles,reveals the pressure distribution law inside the gas nozzle,and conducts field tests on an oil production platform in the South China Sea.The results show that:①The throttling pressure drop of the gas nozzle is mainly concentrated in the contraction zone of the nozzle.When the CO2 molar ratio is 20%～80%,the throttling pressure drop decreases in a quadratic function with the increase of CO2 content,and the pressure drop changes more significantly when the CO2 molar ratio is 20%～50%.②Under the action of a single factor,the throttling pressure drop increases in a quadratic function with the increase of flow rate,increases linearly with the rise of temperature,and decreases gradually with the increase of gas nozzle diameter and outlet pressure.③Under the flow rate-temperature coupling effect,the flow rate dominates the increase of pressure drop,and the decrease of temperature can slightly offset the increase of pressure drop.Under the outlet pressure-temperature coupling effect,the two factors synergistically enhance the inhibition effect on pressure drop.④In the field test,a gas nozzle with a diameter of 5.2 mm is adopted,the actual wellhead gas injection pressure is 0.6 MPa higher than the target pressure,and the error between the actual injection flow rate(7.2×104 m3/d)and the target injection flow rate(6.1×104 m3/d)is less than 20%,which meets the requirements of field layered gas injection allocation.The research on the variation law of the throttling pressure drop of CO2-bearing natural gas nozzles under multi-factor and coupling effects can provide reliable theoretical and technical support for the accurate selection of downhole nozzles and the dynamic regulation of layered gas injection flow rate in layered gas injection wells with high CO2 content.
任伟;刘肖健;刘兴斌;何威
中法渤海地质服务有限公司湛江分公司,广东 湛江 524000东北石油大学物理与电子工程学院,黑龙江 大庆 163318东北石油大学物理与电子工程学院,黑龙江 大庆 163318中法渤海地质服务有限公司湛江分公司,广东 湛江 524000
天文与地球科学
分层注气含CO2天然气湍流模型气嘴节流压降敏感性分析注气调配注气流量
layered gas injectionCO2-bearing natural gasturbulence modelgas nozzlethrottling pressure dropsensitivity analysisgas injection allocationgas injection flow rate
《测井技术》 2026 (3)
545-553,9
国家自然科学基金项目"网络模型的智能分层注水井压力脉冲数据传输方法"(52174021)
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