摘要
泡沫钻井环空流道中的两相流体随压力和温度的变化,其泡沫质量和流速随井深连续减小,当井深超过一定范围时,循环流体的液体体积系数增大,流型发生突变,由泡沫流转换为气泡分散流,气泡间无干扰,不存在高强度液膜,其悬浮能力、切力和流速值很低,无法实现高机械钻速下的有效携岩。该井深值被定义为泡沫钻井的"极限井深"。结合新疆油田泡沫钻井沉砂卡钻的实例,从泡沫的悬浮和携带岩屑的机理研究入手,对现场数据进行模拟和分析,充分论证了泡沫存在携岩的"极限井深"的科学性,认为泡沫钻井超过井深4000m后需进行其携岩能力评价,并采取相应的有效措施以提高泡沫携岩能力。
In this paper, the so called Ultimate Depth of foam drilling was defined. Based on some sticking cases of foam drilling in Xinjiang oilfield and the mechanism of carrying and suspending cuttings by foam, the existence of Ultimate Depth was demonstrated. The result shows that the performance of carrying cuttings should be evaluated while the depth is more than 4,000 m, and some measures of improving carrying performance should be taken.
出处
《钻井液与完井液》
CAS
2010年第4期4-6,共3页
Drilling Fluid & Completion Fluid
关键词
泡沫钻井
携岩能力
极限井深
Foam drilling
Carrying cuttings performance
Ultimate depth
