泥页岩水化试验研究

Experimental study on clay shale while under hydration

和冰

He Bing

辽河油田公司曙光采油厂，辽宁 盘锦 124109

(Shuguang Oil Production Plant, Liaohe Oilfield Company, CNPC, Panjin 124109, China).

由于泥页岩中含有水敏性黏土矿物，与钻井液接触时，泥页岩与钻井液相互作用，产生水化膨胀，其结果不仅改变了井眼周围的应力分布，而且由于吸水造成泥页岩的强度降低，这就使得泥页岩地层的井壁失稳问题非常严重,水化作用使围岩变成变含水、变模量和变强度的复杂介质。对水化后泥页岩的力学性能参数进行试验，得出了其随含水量的变化规律，并回归出泥页岩的强度参数与含水量的关系式，对于解决泥页岩地层的井壁失稳问题具有重要意义。

Clay shale usually contains a significant amount of water-sensitivity clays. When in contact with drilling fluid, clay shale will interact with drilling fluid, which leads to swelling due to hydration. This not only alters the stress distribution near the borehole, but also reduces the strength of clay shale. So, the problem of the borehole instability in clay shale becomes very serious. Due to hydration, clay shale becomes a complex media, the water content, the elastic modulus and the strength of which are all changeable. Experiments were carried out on the mechanical properties of clay shale while under hydration and the relationship was determined
between the properties and water content of clay shale. The study methods and the conclusions are of great significance for solving the borehole instability in clay shale.