Abstract: Some problems have been encounted,such as hole redressing,drill pipe sticking,preventing and blocking electrical logging and leaving plug in well cementation caused by sidewall instability during exploration and exploitation of Pubei,Shenquan and Yanmuxi areas in the western Tuha Oilfield.The fabric and physical-chemical properties of rock samples in the western Tuha Oilfield were analyzed by X-ray diffraction,SEM,specific hydrophilic capacity measuring,zeta-potential analysis,and experimental technique of clay shale pressure transmission.The sidewall instability mechanism of these areas was discussed.According to the “multi-component combination” anti-sloughing theory,the potassium-calcium-alcohol intensive anti-sloughing drilling fluid suitable to the formation of the western Tuha Oilfield was developed by selecting all kinds of additives and optimizing formulation.The results of field test showed that this kind of drilling fluid can meet the requirement of oilfield.

Key words: Tuha Oilfield, sidewall stability, instability mechanism, anti sloughing drilling fluid, experimental study

摘要： 在勘探开发过程当中,吐哈油田西部的葡北、神泉和雁木西区块存在着严重的井壁不稳定等原因导致的划眼、卡钻、电测遇阻遇卡、固井留塞等问题.利用X射线衍射、电镜扫描、电动电位分析和泥页岩压力传递实验研究新技术,以及比亲水量测试等实验手段,对吐哈西部油田岩样的结构及理化性能进行了系统分析,论述了该地区复杂地层井壁失稳机理.依据“多元协同”防塌理论,通过单剂优选和配方优化实验,研制出了适合吐哈西部油田地层特性的钾-钙-醇强化防塌钻井液体系.现场试验结果表明,该钻井液体系能满足现场使用的要求.

关键词: 吐哈油田, 井壁稳定性, 失稳机理, 防塌钻井液, 实验研究