| 摘要 |
New polymers, and their applications in water-based wellbore service fluids, such as, for example, drilling fluids, yield desirable filtration control and rheological properties to such fluids even after exposure to HTHP aging. Typical temperatures encountered during such aging are around 350-400° F. and the duration of the exposure is some significant time such as 16 hours or longer. Preferably, the polymers are random terpolymers of N-vinylcaprolactam, vinyl sulfonate monomer 2-acrylamido-2-methyl-1-propanesulfonic acid, and monomer acrylamide, most preferably in a molar ratio of 15:20:65 respectively. The polymers reduce HTHP filtration volumes in fresh water, sea water, potassium chloride, and lime mud systems. The polymers may also be used to inhibit or reduce shale erosion.
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