气体钻水平井段环空岩屑床分布规律研究  

DISTRIBUTION LAWS OF ANNULUS CUTTINGS BEDS OF HORIZONTAL WELL IN GAS DRILLING

作　　者：杨晓光 柳贡慧[1,2] 李军[1] 罗整 吴琦 

机构地区：[1]中国石油大学石油工程学院北京 [2]北京信息科技大学 [3]中国石油川庆钻探公司钻采工程技术研究院

出　　处：《钻采工艺》2014年第2期5-7,15,共4页Drilling & Production Technology

基　　金：国家自然基金重点项目“控压钻井测控理论及关键问题研究”(编号:51334003);国家自然基金面上项目“气体钻井动态低温条件下岩石破坏机理研究”(编号:51274220);国家973项目“深井复杂地层钻井压力系统模型与规律”(编号:2010CB226704)资助

摘　　要：目前关于气体钻水平井的理论研究大都集中在最小注气量的选择上,而对气体钻水平井水平段井筒内的岩屑床分布规律缺乏深入的理论研究。文章通过对气体钻水平井段气固流动特性的分析,应用气固两相流理论、扩散理论,建立了适合气体钻水平井水平井段三层流动的理论模型,即上层悬浮层、中间滑动床及底层岩屑固定床。根据现场某井数据进行了实例计算,计算结果表明,气体钻水平井在气速大于沉降速度时,水平井筒内的岩屑床为滑动床;滑动床的高度随着机械钻速的增高而增大,随着气速的增加、钻杆尺寸的增加而减小;相同条件下水平井段滑动床面积从趾端到根端逐渐降低。当气体返速小于沉降速度时则水平井筒内的流动为三层流动,滑动床、岩屑固定床的分布规律趋势与两层流动时大体相同。At present,the theoretical studies of gas drilling horizontal wells mostly concentrated in the choice of smallest injection gas volume,while its wellbore cuttings bed distribution laws didn't been studied in depth.The three layers flow mode suited for gas drilling horizontal well was established based on gas-solid flow characteristics analysis in gas drilling,using gas-solid phase flow theory and diffusion theory,namely upper superposed layer,the middle Slide cuttings bed and the lower stationary cuttings bed.Taking the drilling data from a well as an example,the calculation results showed that,when the gas velocity is greater than cuttings settling velocity,the cuttings bed in lateral segment was sliding bed;the sliding bed height increased with the increasing of the ROP,reduced with the increasing of gas velocity and drill pipe size;the sliding bed area from the toe-end to the root-apex gradually reduced in same conditions.When the gas velocity is less than cuttings settling velocity,the gas flow is the three layers flows in horizontal wellbore,the cuttings bed distribution trend is same substantially with the two layers flow.

关 键 词：气体钻水平井 岩屑滑动床 固定床 

分 类 号：TE243.1[石油与天然气工程—油气井工程]