Multi-functional efficient oil scavenge polymer and preparation method of raw material graft modification starch thereof

Abstract

The invention provides multi-functional efficient oil scavenge polymer which is characterized by being a copolymer formed by copolymerizing monomer acrylamide, crylic acid or 2-acrylamide-2 methyl-1-propanesulfonic acid and monomer graft modification starch. Content of acrylamide and crylic acid or 2-acrylamide-2 methyl-1-propanesulfonic acid occupies, by mass, 60-90% of total mass of two monomers, and the two monomers occupy 30-60% of total mass. Alkyl halide is added in the process of preparation of the monomer graft modification starch. Productivity of the multi-functional efficient oil scavenge polymer reaches more than 90%, is efficient, environment-friendly and high in interfacial activity, enables oil-water interface tension of oil reservoir crude oil to arrive at 10-2-10-3Mn / m, and is free of dehydration after 24-hour emulsification, rapid in demulsification, high in temperature resistance and shear resistance, non-toxic, environment-friendly and good in biodegradability. Alkyl halide is added in the process so as to enable water absorption rate of the prepared monomer graft modification starch to be higher.

Description

technical field [0001] The invention relates to an oilfield chemical polymer, in particular to a multifunctional high-efficiency oil displacement polymer and a preparation method of grafted modified starch as a raw material thereof. Background technique [0002] At present, the water cut in my country's oilfields is generally above 80%, and some even reach above 90%. The recovery degree of recoverable reserves is generally above 60%, and some even reach 70%-80%. Under the condition of high water cut and high degree of recovery, the distribution of oil and water in the reservoir is very complicated, and the remaining oil is highly dispersed in space, which greatly increases the difficulty of production. Due to the severe heterogeneity of continental sediments in my country, the coefficient of variation of permeability is generally greater than 0.5, which is not conducive to water flooding but beneficial to polymer flooding. Furthermore, the viscosity of crude oil in the eas...

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Problems solved by technology

During the oil displacement process of water flooding and polymer flooding, most of the injected water and polymer solutions enter the high-permeability layer, and the low-permeability layer has low sweep, and the polymer solution is easily affected by temperature, shear, bacteria, etc. The viscosity retention rate is very low, which seriously affects the oil displacement effect of water flooding and polymer flooding; on the other hand, the polymer solution does not have the ability to greatly reduce the interfacial tension with the formation crude oil, and the oil washing efficiency is poor; secondly, the polymer solution Does not have emulsification ability with crude oil, resulting in reduced recovery of polymer flooding

[0004] The water absorption rate of monomer graft modified starch prepared according to the existing method is not high and still needs to be improved

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