A branched viscoelastic powder oil displacement agent and its preparation method

Abstract

The present invention provides a branched viscoelastic powder oil displacement agent and its preparation method. The method is carried out as follows: a. Acrylamide aqueous solution is prepared according to the ratio of acrylamide: water = 100:200-250 parts by weight; b. First take the acrylamide aqueous solution in step a and put it into a three-neck container, and in a water bath at 10°C to 15°C, blow nitrogen gas for 15 to 30 minutes. The persulfide aqueous solution prepared according to the ratio and the polyhydroxy compound aqueous solution prepared according to the ratio of polyol: water = 0.0018 to 0.004: 40 to 60 parts by weight are added to a three-neck container for reaction, and after the temperature of the reaction solution exceeds 1 °C , stop the nitrogen flow, and start to record the temperature of the reaction system; c. When the temperature of the reaction system no longer rises, put the three-neck container in a water bath at 70-85°C and keep it warm for 4-6 hours, then take out the gel, dry it, Pulverize to obtain viscoelastic powder oil displacement agent products.

Description

Technical field: [0001] The invention relates to the technical field of tertiary oil recovery, in particular to a branched viscoelastic powder oil displacement agent capable of enhancing oil recovery and a preparation method thereof. Background technique: [0002] At present, most oilfields in my country have entered the development stage of high water cut or extremely high water cut. The traditional oil displacement agent, partially hydrolyzed polyacrylamide, is injected into the reservoir and advances along the high permeability layer or belt, and few enter the low permeability layer. The volume of the oil displacement agent is swept Therefore, a partially cross-linked polyacrylamide viscoelastic particle oil displacement agent with a large number of branched chain structures was developed. Patent CN101775275B discloses a viscoelastic particle oil displacement agent and its preparation method. Dimethylaminoethyl methacrylate is used as a functional monomer in combination wi...

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Problems solved by technology

[0002] At present, most oilfields in my country have entered the development stage of high water cut or extremely high water cut. The traditional oil displacement agent, partially hydrolyzed polyacrylamide, is injected into the reservoir and advances along the high permeability layer or belt, and few enter the low permeability layer. The volume of the oil displacement agent is swept Therefore, a partially cross-linked polyacrylamide viscoelastic particle oil displacement agent containing a large number of branched chain structures was developed.

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