Such accidents as lost circulation, well kick and differential pressure sticking occurred in section of 4772~5301 m because of high permeable sandstone and high formation pressure existence in this formation.
该井在4772～5301 m井段的钻井过程中因砂岩层渗透性好、油气层压力系数高,发生了多次井漏、溢流和压差卡钻等复杂事故,决定完钻,下入φ127 mm尾管。
Analysis was made on the causes of differential pressure sticking in drilling in oil shale;and the prevention and treatment measures were proposed with field cases.
分析了油页岩地层钻进中压差卡钻发生的原因,提出了预防压差卡钻的途径及处理方法,并通过工程实例来强调预防为主的重要性。
The mechanism of differential sticking isbriefly analyzed, and some factors effecting criticalvalue of differential sticking are pointed out.
简要分析了压差卡钻的机理，提出了影响压差卡钻临界值ΔＰＬ的几个因素。
It is difficult to drill in this block, for the strong mud making property of the formation and high concentrations of Ca 2+ and Mg 2+ in industrial water, and engineering accident potentials such as well sloughing, lost circulation, well blowout and pressure differential sticking exist during the whole drilling job.
安 2 8断块地层承压能力低 ,全井压力形成低 高 低分布 ;地层造浆性强 ,生产用水中钙、镁离子含量高 ,钻井施工难度大 ,井塌、井漏、井喷、压差卡钻等工程事故隐患伴随整个钻井过程 ,在以往钻井过程中 ,经常出现钻井液切力大、触变性强 ,加重引起粘度和切力升高 ,形成加重 排放 再加重的恶性循环。
