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

The patent is about a type of gel used in petroleum recovery. The gel is made by using a mixture of monomers and three types of crosslinkers. One of these crosslinkers, called PEI, is a tertiary crosslinker that is stable and effective in resisting washout. The gels produced by this crosslinker are stable and can withstand high temperatures. The amount of PEI used and the amount of swelling needed are factors that can affect the rate of gelation. Other additives can also be included in the gel to improve its properties. The patent also describes how the gel can be controlled to delay its crosslinking and how it can be destroyed with strong oxidizing agents. Overall, the technology described in this patent allows for effective and stable gels for use in oil recovery applications.

Problems solved by technology

Further, the gelation time decreases and gelation strength weakens with increasing the salinity of gelling solution.

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