Additive for cementing wells
AssigneeBASF SE
InventorsRoland Reichenbach-klinke, Tinton Setiawan, Johann Plank
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Abstract
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.
Claims21
An additive comprising a polyalkylenimine and a sulphonated, formaldehyde-containing condensate, wherein the condensate is a mixture of at least one sulphonated ketone/formaldehyde resin and a polycarboxylate ether.
An additive comprising a polyalkylenimine and a sulphonated, formaldehyde-containing condensate, wherein the condensate is a sulphonated ketone/formaldehyde resin and wherein the polyalkylenimine is selected from the group consisting of polyethylenimine, polypropylenimine and polybutylenimine, and wherein the polyethylenimine comprises at least one member selected from the group consisting of N-methyl polyethylenimine, N-acetylpolyethylenimine and N-butylpolyethylenimine, wherein the proportion of the sulphonated ketone/formaldehyde resin in the condensate is in the range of from 40 to 90% by weight.
Dependencies are inferred from the claim text.