摘要
SK气田古近系地层发育巨厚的膏岩、泥岩、夹泥质粉砂岩,构造高陡,处于异常高压和强地应力状态,钻井过程中井壁垮塌和井漏较严重。利用声波时差和密度等测井资料和岩心实验及实钻数据,针对古近系地层钻井井壁失稳的问题,从岩石力学角度出发,考虑地层倾斜对地应力的影响,建立适合工区高陡地层的地应力计算模型;考虑岩石剪切强度、裂缝发育情况和水平主应力比对井壁稳定性的影响,引入抗剪强度、渗透率增大系数和水平主应力比建立古近系地层钻井井壁稳定性判别图版。利用该图版能快速准确地判断钻井过程中是否发生井壁垮塌和井漏,可为钻井设计及施工提供理论指导和决策依据,值得推广应用。
Paleogene strata of the SK structure grow thick gypsum rock and mudstone,argillaceous siltstone with abnormal high pressure and strong stress,where the dip angles of formation change big,borehole collapse and lost mud are serious during the process of drilling.Sonic and density logging data and core experiments and real drilling data are used in this paper to solve the Paleogene formation wellbore instability problems;from the view of rock mechanics and considering formation tilting effect on stress,first we establish stress model for high steep layer.Secondly considering the influence of rock strength,fracture development and horizontal main stress ratio on stability of well wall,the shear strength,the increase of permeability coefficient and horizontal principal stress ratio are used to build the discriminant chart of Paleogene.Research shows that the above the chart can rapidly and accurately determine whether the collapse and lost circulation in drilling process,so providing theoretical guidance and decisionmaking basis for the design and construction of drilling,it is worthy of popularization and application.
出处
《测井技术》
CAS
CSCD
2015年第5期634-639,共6页
Well Logging Technology
关键词
测井评价
岩石力学分析
高陡构造
水平主应力比
井壁稳定
判别图版
log interpretation
rock machanics analyse
high and steep structure
horizontal principal stress ratio
borehole stability
identification chart
