阳离子钻井液用膨润土的改性研究

STUDY ON BENTONITE USING FOR CATIONIC DRILLING GLUID

用非离子表面活性剂与膨润土在一定的反应条件下发生物理、化学反应 ,对膨润土进行化学改性反应后的膨润土其表面电性发生改变 ,即膨润土胶体的ZETA负电位变至接近于零电位 ,改性后的膨润土能很好地适用于阳离子钻井液体系。在阳离子钻井液体系中 ,使用改性膨润土配浆不用加入两性离子或阴离子型护胶剂 ,改性膨润土能很好地与大分子量阳离子聚合物和小分子量阳离子化合物配伍 ,这样从根本上解决了阳离子钻井液体系中阴、阳离子聚合物不配伍的问题 ,使阳离子钻井液体系变得更加简单 ,也更便于现场维护 。

A method for modifying bentonite by using surfactants is proposed.When the physical and chemical reaction of the bentonite with nonionic surfactants is made under certain conditions,the ion property on the surface of the bentonite is changed.The ZETA potential of the bentonite colloidal can be changed nearly to zero,and the uppgraded bentonite can be adequate for the cationic drilling fluid.While using the modified bentonite to make up the drilling fluid,the modified bentonite can match to cationic polymer with a large molecular weight or compound with a small molecular weight,without adding amphoteric or negative ionic guard colloidal.So the problem that anionic and cantion polymer can not match in the cationic drilling fluid could be completely solved,which makes the application of cationic drilling fluid becomes more simple and easy in oilfield.