| 摘要 |
<p>A coalbed formation is stimulated to improve the recovery of methane which involves injecting into the coalbed formation an aqueous acid solution containing an organic amphoteric tertiary ammonium compound having from 1 to 3 tertiary ammonium groups, each N of which contains at least one one C3 to C4 unsaturated caboxylic acid group, and wherein the compound contains a terminal benzyl or C5-C19 alkyl group.</p> |
