@ A new and improved composition and method for profile modification of subterranean formations characterized by high reservoir temperatures and/or harsh brine conditions are disclosed. The new and improved profile modification agents comprise a gelable composition comprising:
(a) water;
(b) a water-thickening and crosslinkable amount of a water-dispersible copolymer comprising from about 30 to about 99 mol % of units derived from at least one N-sulfohydrocarbon substituted acrylamide monomer copolymerized with from about 1 to about 70 mol % of units derived from at least one other monomer bearing a carboxyl group or a carboxyl precursor group; and
(c) an amount of a polyvalent metal sufficient to crosslink the copolymer to form a stable gel. The profile modification agents are effective to alter the permeability of preselected portions of an underground formation by forming strong gels which are stable in harsh brine at temperatures of up to about 120°C. The composition and method are particularly adapted for use in enhanced oil recovery operations.
本研究公开了一种新的、改进的组合物和方法,用于对以储层温度高和/或盐
水条件恶劣为特征的地下地层进行剖面改良。新型改进型剖面改良剂包括一种可凝胶化的组合物,其中包括:
(a)
水
(b) 一定量的可遇
水增稠和交联的
水分散性共聚物,该共聚物包含约 30 至约 99 摩尔 % 的单元,这些单元来自至少一种 N-磺羟烃取代的
丙烯酰胺单体,与约 1 至约 70 摩尔 % 的单元共聚,这些单元来自至少一种带有羧基或羧基前体基团的其他单体;以及
(c) 一定量的多价
金属,足以使共聚物交联形成稳定的凝胶。剖面改性剂通过形成在温度高达约 120°C 的苛刻盐
水中稳定的强凝胶体,可有效改变地下地层预选部分的渗透性。这种组合物和方法尤其适用于提高石油采收率的作业。