大位移井的井壁稳定力学分析

从井壁稳定的力学机理出发,分析大位移井周的应力分布规律,建立大位移井井壁稳定的力学模型,并据此编制了Windows环境下的井壁稳定分析软件,形成一个方便工程问题分析的集成环境,利用该软件分析了影响井壁稳定性的因素,提出了大位移井钻井的最优井斜方位和安全泥浆密度的选择方法。 

WELLBORE STABILITY ANALYSIS OF EXTENDED REACH WELLS

Stability of extended reach wells is an important subject. Instability problems like lost circulation and borehole collapse during drilling operation lead to poor hole conditions causing a lot of problems like poor cement displacement and others. As a result, excessive nonproductive time and expensive wells are experienced.
This paper is based on a linear elastic and isotropic mechanics models for stress distribution around extended wells, with the aim of improve understanding the general behavior of extended wells. According to the established stability mechanics models, a wellbore stability simulator is developed, which runs under Microsoft Windows with friendly interface, high efficiency of field problem analysis. By using the software, the influence of certain factors on wellbore stability is analyzed. These factors include in-situ stress state, deviation, azimuth, strength rock, mechanical property and mud performance. Finally, the guide to determination of the azimuth and the safe mud density range for extended reach wells is presented.