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

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