西南石油大学学报(自然科学版) ›› 1998, Vol. 20 ›› Issue (3): 45-48.DOI: 10.3863/j.issn.1000-2634.1998.03.012

• 钻采工艺与设备 • 上一篇    下一篇

两向水平应力不等条件下泥浆密度的确定

马德新

  

  1. (中国海洋石油渤海公司钻井部,天津300452)
  • 收稿日期:1998-03-17 修回日期:1900-01-01 出版日期:1998-08-20 发布日期:1998-08-20
  • 通讯作者: 马德新

Defining Mud Density Under Conditions of Unequal Horizontal Stresses

Ma De-xing   

  1. ( Bohai Oil Company of China Offshore Oil Company, Tianjin, 300452)
  • Received:1998-03-17 Revised:1900-01-01 Online:1998-08-20 Published:1998-08-20
  • Contact: Ma Dexing

摘要: 降低泥浆液柱压力对油气层的压差和保持井壁稳定是钻井工程亟待解决的问题,对于地应力异常地区显得更为迫切。为了解决油气层污染和井壁稳定的难题,在弹塑性力学理论和岩石力学理论的基础上,应用摩尔—库伦屈服准则,阐述了井眼周围岩石弹塑性状态的形成机理及应力、位移的分布情况,推导出了井眼塑性屈服范围和泥浆液柱压力、水平地应力以及岩石强度的关系式。与其它理论相比,该理论所确定的保持井眼稳定的泥浆密度范围更广,有利于降低对油气层的压差和近平衡钻井。同时,也提出了一些具体技术来保证这一理论的应用。

关键词: 井眼稳定, 岩石应力, 位移, 泥浆密度

Abstract: Lowering pressure difference on production zone and keeping well wall stability are problems much needed to be solved in petroleum engineering, espe-cially in areas with abnormal rock stress. Based on the theory of elasto-plasticity and rock mechanics, applying Mohr-Coulomb yield criteria, this paper
presents a mechanism of elasto-plastic state occur-ring in rocks around the wellbore, describes the cor-responding distribution of stress and displacement, and formulates the equation relating mud hydraulic
pressure, horizontal rock stress to rock strength.Compared with other approaches, range of mud den-sity values required for a stable well wall is wider in this approach, which is beneficial to lowering pres-sure difference on production zone and to performing near balance drilling.

Key words: Hole stability, Rock stress, Displacement, Mud viscosity

中图分类号: