鑽井泥漿對泥岩水化及井壁穩定的影響

The Effects of Drilling Fluids on Shale Hydration and Associated Wellbore Stability Problems

王建力(Chein-Lee Wang)

《鑛冶：中國鑛冶工程學會會刊》 38卷2期 (1994/06) Pp. 92-100+20

摘要

在深井鑽探時，若遇到泥岩岩層，泥岩會因為濕度的變化而改變其性質：例如，強度及彈性模數等的改變。由於泥岩與鑽井泥漿之間作用發生水化而膨脹破壞所造成井壁崩塌的問題，在鑽井工程上扮演著很重要的角色。針對泥岩水化的現象，作者已提出一套力學模式來預測。此理論對於一般對濕度極敏感的岩石均可適用。研究顯示：不同的鑽井泥漿對於泥岩水化會有不同的效應。本文將根據作者的模型對幾種常用的鑽井泥漿所造成泥岩水化的程度及所伴隨井壁穩定的問題進行分析研究。

並列摘要

When a deep well is drilled through moisture-sensitive shale rock media, hydration due to the interaction between shales and drilling fluids may likely occur. The shale hydration can cause shale rocks to swell and degrade. The wellbore collapse resulting from the shale hydration is considered an important problem in drilling engineering. A mechanical model predicting the wellbore instability due to shale hydration has been proposed by the author. The theory attempts to quantify the cause of shale hydration and is applicable to moisture-sensitive rocks in the field. This study shows that the choice of drilling fluids has effect on the severity of shale hydration and hence is an important factor in the wellbore stability problems.