波动压力对浅层大位移井安全密度窗口的影响  

The Influence of Fluctuating Pressure on Security Density Window of Shallow Extended Reach Wells

作　　者：王啸 张磊 刘亮 侯欣欣 李文龙 WANG Xiao;ZHANG Lei;LIU Liang;HOU Xinxin;LI Wenong(Tianjin Branch Company,CNO0C(China)Co.,Ltd.,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《石油工业技术监督》2023年第8期56-59,64,共5页Technology Supervision in Petroleum Industry

摘　　要：浅部地层承压能力低,井壁失稳与井底压力控制密切相关,过大的波动压力易导致井漏等井下复杂情况。基于起下钻过程中引发的波动压力为目标,以起下钻引发的波动压力为研究对象,建立了大位移井起下钻波动压力计算模型,并开展起下钻速度、钻柱加速度、钻井液密度、流性指数、稠度系数及环空间隙对波动压力影响的定量分析。结果表明:当起下钻加速度为0.15m/s^(2),波动压力当量密度增加0.08g/cm^(3);起下钻速度由0.2m/s增大至0.5m/s时,波动压力当量密度增加0.17g/cm^(3);同时,钻井液性能参数的增加和环空间隙的减小,也引起波动压力增加,进而导致安全泥浆密度窗口变窄。研究结果给出了保证井壁稳定的合理工程参数范围,为现场施工提供指导。The bearing capacity of shallow formation is low,wellbore instability is closely related to well bottom pressure control,and ex-cessive fluctuating pressure is easy to cause leakage and other downhole complex situation.With the fluctuating pressure caused in the process of tripping as the target,and with the fluctuating pressure caused by tripping as the research object,the caleulation model of fluctuating pressure in extended reach well tripping was established,and quantitative analysis was carried out around the influence of tripping speed,drill string acceleration,drilling fluid density,fluidity index,consistency coefficient and annular space gap on fluctuating pressure.The results show that the equivalent density of fluctuating pressure increases by 0.08 g/cm^(3) when the tripping acceleration is 0.15m/s;The equivalent density of fluctuating pressure increases by 0.17 g/cm^(3) when the tripping speed increases from 0.2m/s to 0.5m/s.Meanwhile,the increase of drlling fluid performance parameters and the decrease of annulus space can cause the increase of fluctuating pressure,and thus lead to the narrow of safe mud density window.The research results of this paper recommend a reasonable range of engineering parameters to ensure the wellbore stability,and provide guidance for site construction.

关 键 词：大位移井 波动压力 井壁稳定 安全密度窗口 

分 类 号：TE28[石油与天然气工程—油气井工程]