石油学报 ›› 2011, Vol. 32 ›› Issue (3): 529-533.DOI: 10.7623/syxb201103026

• 石油工程 • 上一篇    下一篇

复杂井眼条件下旋转套管速度对固井质量的影响

步玉环  郭胜来  马明新  李  红   

  1. 中国石油大学石油工程学院  山东青岛  266555
  • 收稿日期:2010-08-06 修回日期:2010-10-22 出版日期:2011-05-25 发布日期:2011-07-19
  • 通讯作者: 步玉环
  • 作者简介:步玉环,女,1966年2月生,2005年获中国石油大学(华东)油气井工程专业博士学位,现为中国石油大学(华东)石油工程学院教授,主要从事油气井工程的教学及科研工作。
  • 基金资助:

    国家支撑计划课题(2008BAB37B03)资助。

Influence of rotating casing speed on well-cementing quality under the bad hole conditions

BU Yuhuan  GUO Shenglai  MA Mingxin  LI Hong   

  • Received:2010-08-06 Revised:2010-10-22 Online:2011-05-25 Published:2011-07-19

摘要:

针对改善旋转套管周围流体的流动形态从而有效地避免钻井液的滞留问题,根据赫巴模型的本构方程和非牛顿流体力学的有关理论,建立了赫巴模型下的套管与井壁间水泥浆旋转流动模型。采用数值计算方法,得到了便于计算的套管最小转速与环空间隙因子的关系,以及环空中水泥浆旋转速度径向分布规律。针对实际施工中存在的井眼扩径情况,计算并分析了井径扩大率对套管最小转速的影响。结果表明:环空间隙越小,环空中的水泥浆完全旋转所需的套管旋转速度越小;环空间隙越小,水泥浆的旋转速度沿径向下降得越平缓,效果越好;井径扩大率的增加明显增加了套管最小转速。采用旋转套管去除井壁泥饼,从而在保证下套管安全的前提下,提高了二界面的固井质量。

关键词: 赫巴方程, 旋转套管, 顶替效率, 井径扩大率, 固井质量

Abstract:

The improvement of the flowing state of fluids around rotating casing can effectively reduce the detention of drilling fluids. Based on the constitutional equation of the H-B fluid model and the relevant theories of non-Newtonian fluid mechanics, the present paper established a model for the rotary flow of cement slurry between casing and wellbore wall. Numerical calculations were adopted to obtain a correlation easy to be calculated between the minimum rotary speed of casing and the annular-clearance factor as well as a regulation of the radial distribution of the slurry rotary speed in annular clearance. In addition, the influence of the hole-diameter enlargement rate on the minimum rotary speed of casing was calculated and analyzed in view of hole-size elongation occurring commonly in field construction work. The calculation results demonstrated that the smaller the annular clearance, the lower the rotary speed of casing required by the full rotation of cement slurry in annular clearance; the smaller the annular clearance and the more gently the decline of the rotary speed of cement slurry along the radial orientation, the better the effect of well cementation. The minimum rotary speed of casing significantly increased with the increase of the hole-diameter enlargement rate. The study presented a method to remove mud cakes from wellbore wall by rotating casing so as to improve cementing quality on the premise of safe casing running.