摘要
根据煤层气多分支水平井完井管柱在造斜段的受力变形特点,将完井管柱的变形分为线弹性、弹塑性和扁化变形(塑性流动)阶段,利用弹塑性大变形理论建立了完井管柱承受弯矩与造斜率间关系的计算模型,推导出造斜段完井管柱许可造斜率计算公式。对沁水盆地某煤矿使用的多分支水平井完井管柱的造斜率进行了模拟计算,并与室内实验值进行对比,分析了完井管柱的外径、壁厚和屈服强度对完井管柱许可造斜率的影响。计算结果表明:建立的煤层气多分支完井管柱许可造斜率计算模型与实验值具有很好的一致性,可满足工程需要;完井管柱从线弹性极限变形状态进入弹塑性极限变形状态,井眼许可造斜率变化很小;完井管柱线弹性、弹塑性和扁化变形阶段的许可造斜率随外径的增加而降低,随壁厚和屈服强度的增加而提高,但壁厚影响不显著。
According the field force state of completion strings,the deformations of completion strings in the bend part of multi-branch horizontal well in coal bed methane （CBM） exploration were divided into three phases,which were elastic phase,elastic-plastic phase and ovality phase. The large deformation theory was used to obtain the relationship between the bend subjected to completion strings and build-up rate of well. The equations of completion strings permitted build-up rate were obtained for different deformation phrases,respectively. The completion strings of the Qingshui Basin coal mine in Western China were studied as an example. The simulation results were verified by the experiments. Also,the influences of outer diameter,thickness and yield strength of completion strings on the permitted buildup rate were studied. The comprehensive results indicate that the equations of permitted build-up rate are agreement with the experiments results. The permitted build-up rates change small when the deformation of completion strings become from elastic phrase to elastic-plastic phrase. The permitted build-up rates of elastic phase,elastic-plastic phase and ovality phase decrease with outer diameter increasing and increase with the thickness and yield strength. The thickness of completion strings has unapparent affects on the permitted build-up rates.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2010年第5期787-791,共5页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2010CB226706)
国家科技重大专项大型油气田及煤层气开发(2008ZX05017)
关键词
多分支水平井
完井管柱
许可造斜率
弹塑性变形
multi-branch horizontal well
completion strings
permitted build-up rates
elastic-plastic deformation
