钻井液密度对井眼缩径影响的黏弹性分析  

Viscoelastic Analysis of the Affect of Drilling Fluid Density on Wellbore Shrinkage

作　　者：王耀锋[1] 李军强[1] 杨美全[2] 杨小辉[3] 王水航 

机构地区：[1]西安石油大学机械工程学院,陕西西安710065 [2]中国石化华北石油局西部工程公司,新疆轮台841600 [3]西北工业大学机械学院,陕西西安710072 [4]中国石油测井有限公司技术中心,陕西西安710021

出　　处：《石油钻探技术》2009年第2期18-21,共4页Petroleum Drilling Techniques

基　　金：国家自然科学基金重大项目"复杂条件下钻井技术基础研究"(编号:50234030);国家高技术研究发展计划("863"计划)重点项目"旋转导向钻井系统关键技术研究"(编号:2003AA602013)联合资助

摘　　要：采用开尔文-沃伊特流变模型,推导出了均匀地应力下盐膏层井眼缩径的黏弹性解析解,得到了实际可以测量到的井径变化值,并分析了钻井液密度对井眼缩径的影响。对江汉油田王斜78-1井进行了实例分析,结果表明,盐膏层井眼缩径与岩层自身蠕变特性密切相关,井眼缩径率随着时间的增加而减小且最后趋于一稳定值,随着钻井液密度升高,井眼缩径率降低,当钻井液密度升至某一值时,井眼缩径率降至零,此密度即为临界钻井液密度(王斜78-1井的临界钻井液密度为2.4 kg/L)。钻井液密度高于此临界值并依据岩层自身蠕变特性合理安排作业时间是保证钻井过程中不发生缩径和卡钻等事故的必要条件。Using Kelvin-Viogt model, an analytical equation to predict wellbore shrinkage was derivea and the measurable change of the wellbore diameter in field was obtained. The effect of drilling mud density on wellbore shrinkage is analyzed. The application results on Well Wangxie 78-1 located in Jianghan Oilfield demonstrate that the wellbore shrinkage are closely related to formation creep characteristics. The wellbore shrinkage is decreasing with the increasing of time and finally reaches a stable value. With the increasing of drilling fluid density, the wellbore shrinkage ratio decreases. When drilling fluid density reaches a critical value, wellbore shrinkage ratio is zero. This density is the critical drilling fluid density （2.4 g/cma for Well Wangxie 78-1）. Keeping the drilling mud density above this critical density and optimizing the operation time according to the formation creep characteristics are very important in order to avoid drilling pipe sticking and wellbore shrinkage and other drilling accidents.

关 键 词：钻井液密度 井眼 缩径 黏弹性分析 盐膏层 流变模式 王斜78-1井 

分 类 号：TE21[石油与天然气工程—油气井工程]