| 摘要 |
<p>A method of well construction comprises introducing a settable cement composition down a borehole, wherein the settable cement composition contains pulverulent aplite. The aplite may constitute at least 10% by weight of cement. A cement is disclosed containing at least 30% aplite by weight of cement. Also disclosed is a cement containing aplite having a particle size of less than 200 microns typically from 50 to 100 microns. The aplite reduces cement shrinkage on setting and gives a high strength, low porosity, low permeability cement.</p> |
