This invention relates to drilling fluid additives that suppress clay swelling within a subterranean well and to methods for controlling clay swelling during the drilling of a subterranean well. In one embodiment trihydroxy alkyl amine is reacted with an alkyl halide or a water soluble quaternary amine to form a quaternized trihydroxy alkyl amine. The reaction products can also include condensed reaction products of quaternized trihydroxy alkyl amines. In another embodiment a choline derivative is used. The quaternized reaction products and choline derivatives are characterized by low toxicity and compatibility with anionic drilling fluid components. The products are added to water base drilling fluids which are circulated throughout a well. The drilling fluid additives and the method of controlling clay swelling provide for improved control of the rheological properties of drilling fluids along with increased environmental and drilling fluid compatibility.
本发明涉及可抑制地下井内粘土膨胀的钻井液添加剂,以及在地下井钻探过程中控制粘土膨胀的方法。在一个实施方案中,三羟基烷基胺与烷基卤化物或
水溶性季胺反应,形成季化三羟基烷基胺。反应产物还可以包括季
铵化三羟基烷基胺的缩合反应产物。在另一个实施方案中,使用了
胆碱衍
生物。季
铵化反应产物和
胆碱衍
生物的特点是毒性低,与阴离子钻井液成分兼容。这些产品可添加到
水基钻井液中,在整个井内循环使用。这种钻井液添加剂和控制粘土膨胀的方法可以更好地控制钻井液的流变特性,同时提高环境和钻井液的兼容性。