摘要 |
Methacrylate derivatives are added to salt-containing media to thicken the media, and are particularly useful in the exploration of mineral oil or natural gas deposits. The salt-containing media have a specific density of 1.2 to 2.5 kg/l. The respective methacrylate derivatives, which may be, e.g., mono- and/or difunctional variants, have been found to be particularly suitable, are used in a volume ratio of 100 to 1:1 and an amount of 0.5 to 15% by volume. The thickening of the salt-containing media is effected primarily as gel formation, which can be carried out with the aid of free radical initiators and at elevated temperatures. In particular, completion brines, drilling and drill-in fluids and fracturing fluids and acids having high salt contents are to be regarded as aqueous media. The methacrylate derivatives have a markedly good solubility in heavy brines, as are used primarily in upstream processes of the oil industry. They can also be polymerized subterraneously, and they simultaneously have a high thermal stability.
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