水下油嘴多相节流温降数值模拟及规律研究  

Numerical Simulation and Regularity Study for Throttling Temperature Drop of Multiphase Flow through Subsea Chokes

作　　者：朱军龙 李清平 秦蕊 姚海元 Zhu Junlong;Li Qingping;Qin Rui;Yao Haiyuan(CNOOC Research Institute Co.,Ltd.)

机构地区：[1]中海油研究总院有限责任公司,北京市100020

出　　处：《石油机械》2022年第6期65-71,共7页China Petroleum Machinery

基　　金：国家科技重大专项“深水油气田流动安全保障技术”(2016ZX05028-004-007)。

摘　　要：水下油嘴作为水下采油树的重要部件,用来调节油气井内产出流体的流速和流量,实现油气井的生产运行和关断。由于水下油嘴处于深水高压低温环境,在节流效应影响下极易生成天然气水合物而堵塞油嘴及下游管道,研究油嘴下游温度范围,以对照水合物温压曲线适当调节产出流体的流速和流量,对生产安全至关重要。以Cameron公司的笼套式水下油嘴为研究对象,基于质量、动能、能量守恒原理、传热学和流体力学等理论,以天然气凝析液为介质,建立水下油嘴节流模型,研究了天然气过油嘴的节流温降。采用Fluent软件得到了单相甲烷和气液两相流条件下,水下油嘴的流场分布及温度分布。最后在所建立的模型基础上,研究了入口压力、出口压力、入口温度、气液比例及油嘴开度几个因素对节流温降和油嘴流场分布的影响规律。研究结果可以为深水油气田安全生产提供指导。As a key component of subsea Christmas tree,subsea chokes work in deep water,high pressure and low temperature environment.It is easy to produce natural gas hydrates to block chokes and downstream pipelines due to J-T effect.Therefore,it is very important to study the temperature range downstream of the chokes and compare the hydrate temperature-pressure curves for production safety.In this paper,based on the theories of mass,kinetic energy,energy conservation,heat transfer and fluid mechanics,taking the Cameron subsea chokes as the study object,the subsea choke throttling model was established with natural gas condensate as the medium to study the throttling temperature drop of natural gas through chokes.Fluent software was used to obtain the flow field distribution and temperature distribution of subsea chokes from single-phase methane to gas-liquid two-phase flow.Finally,by using the established model,the effects of inlet pressure,outlet pressure,inlet temperature,gas-liquid ratio and choke opening on the throttling temperature drop and choke flow field distribution were studied.The results show that when fluid passes through the sudden contraction section of subsea chokes,the downstream temperature drops sharply due to J-T effect,and when the temperature drops to a sufficiently low level,hydrate will precipitate and block the pipeline.Controlling the pressure and temperature above the hydrate formation point in production could avoid ice blockage.In addition,the choke opening will indirectly affect the pressure difference,so too small opening is not applicable in operations.The results provide guidance for safe production in deepwater oil and gas fields.

关 键 词：水下油嘴 节流效应 气液两相流 天然气水合物 温度场分布 

分 类 号：TE53[石油与天然气工程—油气田开发工程]