摘要 |
<p>Improved silicate drilling fluids are produced by the addition of tetra alkyl ammonium compounds, in particular tetra methyl ammonium hydroxide to silicate drilling fluid mud to lower the co-efficient of friction between drill string and wellbore. It has also been discovered that the same tetra alkyl ammonium lubricant compounds greatly lessen the viscosity breakdown of swelled hectorite clay in the presence of silicate. This allows the preparation of silicate drilling fluids not only with enhanced lubricity but having stable rheology at the higher temperature and pressures encountered in some drilling operations.</p> |