Constraining pyrite activity in shale
AssigneeSmart Chemical Services, LP
InventorsKevin Smith, Jeffrey Snider, Jimmy Poindexter
Life of this patent
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Abstract
Degeneration of shale caused by oxygen in aqueous drilling, fracturing and completion fluids is minimized by introducing imidazolines modified so that they will be attracted efficiently to pyrites in the shale, thereby forming a protective coating on the pyrites. Inhibiting oxidation of the pyrites sharply reduces physical degradation of the shale in the presence of drilling, fracturing and completion fluids carrying oxygen. The imidazoline is an ionic salt or a beatine.
Claims15
A pyrite control additive for drilling and fracturing fluids for inhibiting oxidation of iron pyrite in shale comprising an ionic salt of (a) an imidazoline of the formula
- where R1 is H or a linear alkyl, or monounsaturated or diunsaturated alkyl or alkenyl group of 1-22 carbon atoms, R2 is —(CH2CH2NH)nCH2CH2NH2 where n is 0-5, and (b) a linear monocarboxylic acid having from 1 to 22 carbon atoms in a molar ratio of (a) to (b) of 1:10 to 10:1.
Dependencies are inferred from the claim text.