摘要
为了在固井施工中,保障水泥浆胶结质量和提高水泥环密封效果,针对采用环空水泥浆顶替钻井液固井时,可能出现的钻井液滞留、顶替效率和顶替界面稳定性的问题,利用CFD流体仿真软件Fluent,针对竖直井建立了长度为100 m,外径为215.9 mm,内径为139.7 mm的环空顶替物理模型,开展偏心度、顶替速度、密度差对环空顶替界面稳定性及顶替效率的影响研究。仿真结果表明,顶替速度是影响顶替界面稳定性及顶替效率的一个因素,当低速度顶替时,顶替界面比较稳定,顶替效率较高;偏心度也会影响顶替界面稳定性及顶替效率,随着偏心度的增加,顶替界面越来越不稳定,界面出现倾斜,顶替效率也随之降低;密度差主要影响顶替界面的形态,在正密度差下,密度差越大,顶替界面越稳定,顶替效率也越高。降低套管偏心度、增大水泥浆的密度及进行低速下的层流顶替可提高界面稳定性,提升顶替效率。以上成果认识,对提升固井效率和固井质量具有一定指导意义。
In order to ensure the cementing quality of cement slurry and improve the sealing effect of cement ring during cementing construction,aiming at the problems of drilling fluid retention,displacement efficiency and displacement interface stability that may occur when annulus cement slurry is used to replace drilling fluid for cementing.This paper uses the CFD fluid simulation software Fluent to establish an annulus displacement physical model with a length of 100 m,an outer diameter of 215.9 mm,and an inner diameter of 139.7 mm for vertical wells.The stability of the annulus displacement interface by eccentricity,displacement speed,and density difference is developed.The simulation results show that the displacement velocity is one of the factors affecting the displacement interface stability and displacement efficiency.When the displacement velocity is low,the displacement interface is more stable and the displacement efficiency is higher.The degree of eccentricity also affects the stability of the displacement interface and the displacement efficiency.With the increase of the degree of eccentricity,the displacement interface becomes more and more unstable,and the inclination of the interface reduces the displacement efficiency field.The density difference mainly affects the shape of the displacement interface.Under the positive density difference,the larger the density difference is,the more stable the displacement interface is and the higher the displacement efficiency is.Reducing the eccentricity,increasing the density of the cement slurry and performing laminar displacement at low speeds can improve the interface stability and the displacement efficiency.The understanding of the above results has certain guiding significance for improving cementing efficiency and cementing quality.
作者
余海豪
徐兆刚
杨浩
房孟
李海洋
吴佳鹏
张驰
江仁杰
YU Haihao;XU Zhaogang;YANG Hao;FANG Meng;LI Haiyang;WU Jiapeng;ZHANG Chi;JIANG Renjie(China University of Geosciences(Beijing), Beijing 100083, China;Shandong Zhaojin Geological Exploration Co. , Ltd. , Shangdong Zhaoyuan 265400, China)
出处
《非常规油气》
2022年第2期119-124,共6页
Unconventional Oil & Gas
基金
2020年校级大学生创新训练计划项目“地聚合物水泥浆体系研发”(x202111415037)。
关键词
固井
水泥浆
顶替效率
偏心度
顶替速度
密度差
cementing
cement slurry
displacement efficiency
eccentricity
displacement speed
density difference
