中文摘要：

由于页岩气地层微裂缝（微—纳米级）发育,长水平段页岩地层钻进时,要求钻井液具有良好的封堵效果,而目前使用的钻井液封堵剂主要针对致密砂岩、碳酸盐、泥岩等地层中的大孔隙（毫—微米级）。因此,页岩封堵效果评价及封堵剂优选又是一门新的课题。研究采用孔、缝为微—纳米级的超低孔超低渗地层＂模拟岩心＂评价微纳米封堵材料的封堵效果,发现其可以有效地封堵页岩发育的微裂缝,有效地控制钻井液滤液进入地层,其封堵效果与加量、粒径分布有着密切的联系。

英文摘要：

When drilling long horizontal shale formations,micro- cracks（ micro- nanometer） development requires drilling with good blocking effect,while the drilling fluid blocking agents currently used are mainly for tight sandstone,carbonate,shale and other formations of large pores（ milli- micron）. So it is a new subject to evaluate the effect of the sealing of shale and optimize plugging agent. In this paper,we used ＂simulated core＂based on micro- nanoscale holes and ultra low permeability formations to evaluate micro and nano sealing materials,and discovered the micro and nano sealer can effectively block microfractures shale development and prevent drilling fluid from filtrating into the formation filtrate. And the results also showed that the blocking effect is closely linked with the increase amount of particle size distribution.