基于气液分离的泵内压力与抽油杆柱纵向振动耦合仿真  

Coupling simulation of the pressure in pump and the longitudinal vibration of sucker rod string based on gas-liquid separation

作　　者：王宏博[1,2] 董世民 张洋[1] 王树强 孙秀荣 Wang Hongbo;Dong Shimin;Zhang Yang;Wang Shuqiang;Sun Xiurong(School of Mechanical Engineering,Yanshan University,Hebei Qinhuangdao 066004,China;Offshore Oil Engineering Co.,Ltd.,Tianjin 300451,China;Department of Environmental Engineering,Hebei University of Environmental Engineering,Hebei Qinhuangdao 066004,China)

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004 [2]海洋石油工程股份有限公司,天津300451 [3]河北环境工程学院环境工程系,河北秦皇岛066004

出　　处：《石油学报》2023年第2期394-404,共11页Acta Petrolei Sinica

基　　金：国家自然科学基金项目(No.51974276);河北环境工程学院科技重点项目(2020ZRZD01)资助。

摘　　要：对抽油杆柱纵向振动的仿真建模是实现抽油机井系统效率仿真与抽汲参数优化设计的基础。针对目前抽油杆柱纵向振动仿真模型均未考虑泵内气液分离对杆柱纵向振动底部边界条件的影响这一实际情况,考虑泵内流体气液分离现象,基于连续流方程建立了泵内压力的仿真模型,改进了杆柱纵向振动的底部边界条件,进而建立了泵内压力与抽油杆柱纵向振动耦合的仿真模型。采用空间离散—时间连续与四阶龙格库塔的混合算法对仿真模型进行求解,实现了对抽油杆柱纵向振动的仿真计算。将仿真示功图与实测示功图进行对比验证了仿真模型的精度。对比仿真结果发现,泵内流体气液分离显著影响抽油杆柱的纵向振动:(1)考虑气液分离现象后,悬点、柱塞的加载与卸载速度更快,杆柱的纵向振动更明显。(2)油井冲数越高、泵径越大,气液分离对杆柱纵向振动的影响越明显;油井沉没度越高、含水率越低、生产气油比越大,气液分离对杆柱纵向振动的影响越明显。研究结果可进一步提高抽油机井系统效率仿真模型的精度。Simulation modeling of sucker rod string’s longitudinal vibration is the basis for efficiency simulation of the pumping well system and optimization design of the swabbing parameters. In view of the fact that the current simulation models of longitudinal vibration of the sucker rod string do not consider the influence of gas-liquid separation in pump on the bottom boundary conditions of the longitudinal vibration of rod string, a simulation model of the pressure in pump is established based on the continuous flow equation to improve the bottom boundary conditions of the longitudinal vibration of rod string, and that of the coupling between the pressure in pump and the longitudinal vibration of sucker rod string is further established. The simulation model is solved by a hybrid algorithm of spatial dispersion and continuous time and fourth-order Ronge-Kutta method, thus achieving the simulation calculation of the longitudinal vibration of sucker rod string. The accuracy of the simulation model is verified by comparing the diagram of simulated power with that of measured power. The simulation results show that the fluid gas-liquid separation in pump significantly affects the longitudinal vibration of the sucker rod string:(1)After considering the gas-liquid separation phenomenon, the loading and unloading speed at the suspension point and plunger is faster, and the longitudinal vibration of rod string is more obvious.(2)The higher the well stroke number and larger the pump diameter, the more obvious the impact of gas-liquid separation on the longitudinal vibration of rod string;the higher the well sinkage, the lower the water content, and the larger the production gas-oil ratio, the more obvious the impact of gas-liquid separation on the longitudinal vibration of rod string. The results of the study can further improve the accuracy of efficiency simulation model for the pumping well system.

关 键 词：抽油杆柱 抽油泵 气液分离 柱塞载荷 纵向振动 

分 类 号：TE933[石油与天然气工程—石油机械设备]