碎屑岩系型石盐矿床软泥岩夹层对钻井的影响与工程对策

Influence of soft mudstone interlayer in clastic hailite deposits on drilling and the engineering countermeasures

摘要:

本文针对江汉盆地江陵凹陷沙市盐矿典型的碎屑岩系型石盐矿床中的软泥岩地层钻井难题进行深入研究。通过对研究区含盐系地层特征及盐井实钻资料分析，系统总结了软泥岩地层对钻井工程安全、效率和质量的影响。在此基础上，提出了一系列针对性的钻井工程技术对策，包括采用高密度欠饱和盐水钻井液平衡地层压力、牙轮钻头+螺杆+倒划眼工具钻具组合以及“以退为进”的试钻钻进方式等。这些对策在实际钻井过程中得到了应用，为后续施工提供了安全和质量保障，有效减少了缩径卡钻等井下复杂情况发生概率，也为其他类似地质条件下的钻井工程提供了重要参考。

Abstract:

This paper conducts an in-depth study on the drilling problems of soft mudstone strata in typical clastic halitite deposits in Shashi salt deposits in Jiangling Sag of Jianghan Basin. Through the analysis of the characteristics of the salt-bearing strata in and the actual drilling data of salt wells， the influence of soft mudstone on the safety， efficiency and quality of drilling engineering was systematically summarized. Based on this， a series of targeted drilling engineering technical countermeasures are proposed， such as the use of high-density undersaturated brine drilling fluid to balance the formation pressure， cone bit+screw+back reaming tool combination， and the testing drilling method of “retreat as advance”. These countermeasures have been applied in the actual drilling process， providing safety and quality assurance for subsequent construction， effectively reducing the probability of downhole complex conditions， and also providing important references for other drilling projects under similar geological conditions.