Crosslinking of swellable polymer with pei

Abstract

The invention is directed to stable and labile crosslinked water swellable polymeric microparticles that can be further gelled, methods for making same, and their various uses in the hygiene and medical arts, gel electrophoresis, packaging, agriculture, the cable industry, information technology, in the food industry, papermaking, use as flocculation aids, and the like. More particularly, the invention relates to a composition comprising expandable polymeric microparticles having labile crosslinkers and stable crosslinkers, said microparticle mixed with a fluid and an unreacted tertiary crosslinker comprising PEI or other polyamine based tertiary crosslinker that is capable of further crosslinking the microparticle on degradation of the labile crosslinker and swelling of the particle, so as to form a stable gel. A particularly important use is as an injection fluid in petroleum production, where the expandable polymeric microparticles are injected into a well and when the heat and/or pH of the well cause degradation of the labile crosslinker and when the microparticle expands, the tertiary crosslinker crosslinks the polymer to form a stable gel, thus diverting water to lower permeability regions and improving oil recovery.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Ser. No. 61 / 729,682, filed Nov. 26, 2012, and expressly incorporated by reference herein it its entirety.FEDERALLY SPONSORED RESEARCH STATEMENT[0002]Not applicable.REFERENCE TO MICROFICHE APPENDIX[0003]Not applicable.FIELD OF THE INVENTION[0004]The invention relates to stable crosslinking of swellable polymers, methods for making same, and their various uses in the hygiene and medical arts, gel electrophoresis, packaging, agriculture, the cable industry, information technology, in the food industry, papermaking, use as flocculation aids, and the like. A particularly important use is as an injection fluid in petroleum production, especially in enhanced oil recovery (EOR) applications.BACKGROUND OF THE INVENTION[0005]Every day, oil and gas companies are challenged to produce as much of their oil reserves as possible. During the primary recovery stage, reservoir drive comes from a number of natural me...

AI Technical Summary

Benefits of technology

[0018]The invention generally relates to smart gels that have stable and labile crosslinkers, allowing swelling in situ in response to a particular stimulus. Further, the swelled polymer is stabilized in situ by further crosslinking, thus forming a gel structure. In preferred embodiments, the amide groups of the fully hydrated acrylamide-based polymers are crosslinked with e.g., polyethyleneimine (PEI), to form a stable three dimensional

Problems solved by technology

Further, the gelation time decreases and gelation strength

Images