鄂北工区井壁失稳原因及对策

Reasons and Countermeasures of Sloughing in the Job Area of North of Hubei

井径扩大率超标是鄂北工区井身质量存在的最大问题,一般都达到20％～30％,严重影响成井质量。简述了工区地层特征,分析了井壁失稳原因,介绍了钾-铵离子聚合物钻井液、两性离子钻井液体系及屏蔽暂堵钻井完井液的主要性能及现场维护措施。

The unallowable wellbore enlargement rate (20%-30%) is the severest problem of wellbore qualities in the job area of north of Hubei. Based on studying in formation characteristics of this area and analyzing factors contributing to sloughing, this paper presents main properties and maintenances of the following muds : potassium-ammonium polymer mud, amphion mud and shielding pluging mud.