Hyperbranched slow-swelling profile control particles and preparation method thereof

Abstract

The invention discloses hyperbranched slow-swelling profile control particles and a preparation method thereof. The profile control particles are prepared by drying, crushing and screening a functional skeleton monomer, an acrylamide monomer and a temperature-resistant and salt-resistant monomer by taking ammonium persulfate or azobisisobutylamidine as an initiating agent and adopting hydrogel prepared by a free radical copolymerization method, wherein the functional skeleton monomer is obtained by adopting methyl methacrylate to perform terminal group modification on polyamide-amine; the temperature-resistant and salt-resistant monomer is N-vinyl pyrrolidone, 2-acrylamide-2-sodium methylacrylsulfonate or sodium vinylsulfonate. The profile control particles disclosed by the invention take a hyperbranched skeleton unit as a core to form a three-dimensional network structure, and form hydrogel with high strength and strong toughness after water swelling to block a high-permeability layer to promote liquid flow diversion, so that the profile control particles can be used for deep profile control of an oil reservoir with the temperature of 60-120 DEG C and mineralization degree of 2*10<4>-20*10<4>mg/L. The preparation method of the profile control particles is reasonable in principle and simple and convenient in operation and has broad application prospects.

Description

technical field [0001] The present invention relates to a kind of oil suitable for reservoir temperature 60 ℃ ~ 120 ℃, salinity degree 2×10 4 mg / L~20×10 4 mg / L hyperbranched slowly expanding deep profile control particles, belonging to the field of oil field chemistry. Background technique [0002] In oilfields in the later stage of water injection development, the advantageous channel formed by water flooding is obvious, especially once the oil layer with prominent inter-layer and intra-layer contradictions sees water, the oil production will decrease rapidly, and most of the crude oil will remain in the formation and it is difficult to recover, and the economic benefit is poor . For such reservoirs, profile control and water shutoff systems can seal high-permeability layers, divert liquid flow, improve water absorption profiles, and are widely used in profile control and water shutoff in high-temperature and high-salt reservoirs. At present, the profile control water pl...

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Problems solved by technology

However, the pre-crosslinked particles with acrylamide as the main agent have fast water absorption and swelling time, rapid swelling under low salinity, plugging the near-wellbore area leads to high pumping pressure, increased brittleness in the later stage of expansion, aging and water loss under high temperature and high salt, Insufficient flexibility and weakened liquid flow steering ability make the effect of profile control not obvious

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