川东复杂地层防塌技术初探

Drilling fluid technology used to reduce hole collapse in East Sichuan

分析了川东地区复杂地质条件下钻井作业中发生井塌的主要原因及几种常见井塌类型,即高角度地层井壁垮塌、易永化地层井壁垮塌、地应力引起的井壁垮塌以及工程因素引起的井壁垮塌等。介绍了川东地区防止井塌的方法:使用防塌钻井液,确定合理的钻井液密度,在地应力强烈的区域钻井应寻找应力差较小的区块钻井或改变井眼轨迹以及利用工程技术处理井塌等。提出了该地区预防和处理井塌中存在的问题知今后的研究方向。

The paper analyzed the causes of hole collapse in east Sichuan Area. and the typical types encountered, including hole collapse caused by high dip and water sensible formation, hole collapse because of formation stress and a number of drilling conditions. By using anti-collapse drilling fluid . adjust ing the drilling fluid to a suitable density, and avoiding drilling through extreme pressure drop adjoining formations or changing well trajectory, hole collapse have been effectively reduced.