中文摘要：

由于泥页岩地层特性以及页岩气钻井工艺技术特点,目前页岩气井多采用成本较高、易污染环境的油基钻井液。优选一种基于纳米材料的水基钻井液体系,该钻井液利用纳米二氧化硅封堵泥页岩微小孔隙,采用磺化沥青Soltex作页岩井壁稳定剂。对该体系的高温高压滤失性能、高温高压流变性、膨胀性、滚动回收率、润滑性、泥饼摩阻系数以及表面张力等参数进行了测试。结果表明,该钻井液对泥页岩有较强的抑制性,抑制效果好于具有强抑制性的聚合醇体系,可防止泥页岩水化膨胀分散,保证井壁稳定;具有很好的润滑性,润滑系数为0.21,泥饼摩阻系数为0.049 7;在120℃下滤失量较低,流变模式较符合赫-巴模式;纳米二氧化硅/纳米碳酸钙近似球型结构,以及与Soltex的协同作用,使钻井液具有低表面张力,可削弱水锁损害。该水基钻井液体系适用于泥页岩地层钻进。

英文摘要：

Shale gas well drilling imposes strict limits to the performance of drilling fluid used because of the shale formation and technical features.A water base drilling fluid formulated with nano material was recently developed in an effort to replace oil base drilling fluid commonly used in shale gas drilling.In this drilling fluid,the nano particles plug the pore throats of shale formation,and the sulfonated asphalt is used to stabilize shale formation.In laboratory study,this drilling fluid showed better shale inhibitive capacity than poly glycol drilling fluids.The friction coefficient of the drilling fluid was 0.21,and that of the filter cake 0.0497.At 120 ℃,this drilling fluid still retained its good property.Low surface tension of this drilling fluid mitigated reservoir damage.This drilling fluid can also be used in shale drilling.