| 摘要 |
<p>An additive based on a polyalkylenimine and a sulphonated formaldehyde-containing condensate and its use as a fluid loss additive in the cementing of wells in the mineral oil and natural gas sector is claimed. Polyethylenimine, polypropylenimine and polybutylenimine are suitable as typical representatives of the polyalkylenimines and may also be derivatised. Preferred condensates are acetone/formaldehyde resins. Those additives according to the invention which are subjected to maturing, in particular by allowing to stand, prior to their use achieve a particularly low fluid loss value.</p> |
