高压高产气井应急试采过程中采气树抗冲蚀性能分析  

Erosion Resistance of Gas Production Tree during Emergent Trial Production of High-pressure and High-output Gas Wells

作　　者：张恩搏 曾德智[1] 李双贵[2] 陈东波[2] 李丹丹 朱红钧[1] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500 [2]中国石化西北油田分公司石油工程技术研究院,乌鲁木齐830011

出　　处：《表面技术》2018年第3期183-190,共8页Surface Technology

基　　金：国家自然科学基金项目(51374177)~~

摘　　要：目的研究高压高产气井在大排量应急试采工况下,日产量和日出砂量对气固两相流采气树冲蚀行为的影响。方法运用CFD数值模拟方法,在Eulerian和Lagrangian坐标系下求解气体-颗粒、颗粒-壁面间的相互作用,并捕捉颗粒运动轨迹。采用用户自定义函数(UDF)编写冲蚀磨损方程,分析日产量和日出砂量对于采气树冲蚀速率、冲蚀位置和颗粒轨迹的影响。结果日产量由100万方增加到1000万方时,采气树内气体流速逐渐增大,最大流速为当地音速365 m/s,最大冲蚀速率则由4.14×10^(-8) kg/(s·m^2)增大至3.462×10^(-7) kg/(s·m^2)。气体从采气树四通内流入两翼支管发生节流,压降随日产量的增加而增大。当日产量为1000万方时,最大压降为1.52 MPa;当日产量超过300万方,气体流入旁通支管时,压降形成的流动功将大部分颗粒直接带入支管,造成主要冲蚀区域由四通内壁扩大至旁通支管内壁。当日出砂量由7.7方增大至38.5方时,最大冲蚀速率由7.121×10^(-8) kg/(s·m^2)增大至3.462×10^(-7) kg/(s·m^2)。结论日产量和日出砂量均与冲蚀速率呈正相关关系,控制应急试采日产量是降低采气树冲蚀速率的有效方式。The work aims to analyze effects of daily output and daily sand output on erosion behavior of gas/solid flow gas production treeduring emergent trial production of high-pressure and high-output gas wells. CFD numerical simulation method was used to simulate interactions of gas-particle and particle-wall in Eulerian and Lagrangian coordinates, and capture motion trail of particles. User defined function （UDF） was used to develop erosion wear equation, and analyze the effects of daily output and daily sand output on erosion rate, erosion position and particle trail of gas production tree. As the daily output increased from 1.0×106 to 1.0×107 m3, gas flow rate in the tree gradually increased to local acoustic velocity of 365 m/s, the maximum erosion rate increased from 4.14×10？8 kg/（s？m2） to 3.462×10？7 kg/（s？m2）. The gas was throttled as it flowed into branch pipes on both flanks from four-way pipe in the tree. Pressure drop increased with the increase of daily output, and the maximum pressure drop was 1.52 MPa when daily output reached 1.0×107 m3. When daily output exceeded 3.0×106 m3, mostparticles were brought in branch lines by flow work caused by pressure drop as the gas flowed into by-pass branch pipes. Hence major erosion regionwas expanded to inner walls of by-pass branch pipes from inner wallsof four-way pipes. As the sand output increased from 7.7 m3 to 38.5 m3, the maximum erosion rate increased from 7.121×10？8 kg/（s？m2） to 3.462×10？7 kg/（s？m2）. Daily outputis positively related toerosion rate. Controlling daily output of emergent trial production is effective approach of reducingthe erosion rate.

关 键 词：采气树 冲蚀 应急试采 日产量 日出砂量 气固两相流 数值模拟 

分 类 号：TG172[金属学及工艺—金属表面处理] TE375[金属学及工艺—金属学]