Practical application of failure criteria in determining safe mud weight windows in drilling operati

来源 :岩石力学与岩土工程学报(英文版) | 被引量 : 0次 | 上传用户:mhappy
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Wellbore instability is reported frequently as one of the most significant incidents during drilling oper-ations. Analysis of wellbore instability includes estimation of formation mechanical properties and the state of in situ stresses. In this analysis, the only controllable parameter during drilling operation is the mud weight. If the mud weight is larger than anticipated, the mud will invade into the formation, causing tensile failure of the formation. On the other hand, a lower mud weight can result in shear failures of rock, which is known as borehole breakouts. To predict the potential for failures around the wellbore during drilling, one should use a failure criterion to compare the rock strength against induced tangen-tial stresses around the wellbore at a given mud pressure. The Mohr-Coulomb failure criterion is one of the commonly accepted criteria for estimation of rock strength at a given state of stress. However, the use of other criteria has been debated in the literature. In this paper, Mohr-Coulomb, Hoek-Brown and Mogi-Coulomb failure criteria were used to estimate the potential rock failure around a wellbore located in an onshore field of Iran. The log based analysis was used to estimate rock mechanical proper-ties of formations and state of stresses. The results indicated that amongst different failure criteria, the Mohr-Coulomb criterion underestimates the highest mud pressure required to avoid breakouts around the wellbore. It also predicts a lower fracture gradient pressure. In addition, it was found that the results obtained from Mogi-Coulomb criterion yield a better comparison with breakouts observed from the caliper logs than that of Hoek-Brown criterion. It was concluded that the Mogi-Coulomb criterion is a better failure criterion as it considers the effect of the intermediate principal stress component in the failure analysis.
其他文献
目的:探讨不同免疫球蛋白(Ig)类型的多发性骨髓瘤(MM)患者血脂变化的临床意义.方法:检测MM患者60例,其中IgG型30例,IgA型12例,IgD型5例,轻链型13例.对照组为健康体检者30例的
目的 分析荨麻疹的病因、临床表现及治疗措施.方法 对2007年2月~2011年2月门诊急诊患者的资料进行系统分析.结果 病因:物理因素6例,感染2例,食物引起5例,药物引起26例,原因不
护理人员绩效考评是对各级护理人员工作中的成绩和不足进行系统调查、分析、描述的过程.是对护理人员工作的效果、效率和效益的考核和评价.合理有效的考评方法是提高护理质量
本研究对男大学生第一学期体育教学活动前后的哈弗台阶指数运用进行了比较,结果显示:4个不同的体育运动项目教学都不同程度地提高了男大学生的心血管机能,其中游泳项目具有更
目的:证实用标准12导联心电图中III导联ST段抬高变化幅度与Ⅱ导联ST段抬高变化幅度的比值≥1诊断下壁合并右室心肌梗死的临床诊断价值。方法:对21例根据临床表现,并经冠脉造
总结7例排钉阻断门奇静脉手术患者的护理经验,包括评估、心理护理、基础护理、并发症的观察及健康教育.观察发现,严密的监测和良好的护理是保证手术治疗效果的重要手段.
近年来,笔者运用益气活血合剂治疗冠心病25例,主要观察患者治疗前后血清型前胶原(PCⅢ)、透明质酸(HA)、层粘蛋白(LN)含量的改变,探讨益气活血合剂在改善冠心病心肌纤维化方
沙疗即埋沙疗法,是维吾尔族劳动人民长期以来与疾病作斗争过程中利用当地独特自然条件治疗疾病的一种古老的维吾尔医学治疗方法,是维吾尔医医学的重要组成部分,维吾尔医学(维
夏令营,多么温馨而又美好的词汇!对于刚刚经过了一学期紧张学习的青少年学生来说,如果能选择一个自己喜欢的夏令营,去放松心情、陶冶情操、体验生活、增长实践能力,这将对他们的
For deep geological disposal of high-level radioactive waste (HLW) in granite, the temperature on the HLW canisters is commonly designed to be lower than 100?C.