Novel anti-shearing branch polymer oil displacement agent and synthetic method thereof

Abstract

The invention discloses a novel anti-shearing branch polymer oil displacement agent and a synthetic method thereof. According to the technical scheme, the following raw materials and monomers in mass percent are used: 73.5-84.95% of acrylamide (AM), 15-25% of sodium acrylate NaAA and 0.05-1.5% of polyamidoamine modified branch skeleton GA taking 1,3-propane diamine as a core. The synthetic method of the novel anti-shearing branch polymer oil displacement agent comprises the following steps of: adding NaAA into a reactor, adding pure water, regulating pH to be 6.5-7.5 with NaOH, stirring and adding AM and GA, preparing a solution with the concentration of 15-30%, introducing nitrogen for 20 minutes, then adding an initiating agent, continuously introducing the nitrogen for 10-20 minutes, and reacting for 3-10 hours at 30-60 DEG C; and finally washing, smashing and drying, thus an AM/NaAA/GA ternary polymer is obtained. The novel anti-shearing branch polymer oil displacement agent shows good shearing dilutability, the problem of injection of medium and low permeation oil reservoirs can be better solved, under lower shearing action, viscosity of the polymer can be rapidly restored, good fluidity control ability and aqueous phase permeability reducing capacity are realized, capacity of a polymer solution for expanding swept volume is improved, and simulated crude oil recovery ratio can be effectively increased by about 12.3%.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to a novel anti-shearing dendrite polymer oil displacement agent used for oil displacement in oil fields to enhance oil recovery and a synthesis method thereof. Background technique [0002] With the deepening of oil and gas exploration and development and the increasing demand for oil and gas resources, medium and low permeability reservoirs have gradually become one of the main sources of oil and gas resources in my country. Among the proven oil reserves in my country, the reserves of medium and low permeability geological oil reservoirs account for more than 1 / 3 of the proven oil and gas resources geological reserves, and account for 3 / 4 of the newly added reserves and the geological reserves put into development since the "Ninth Five-Year Plan" about. (Hu Wenrui. Introduction to the Development of Low Permeability Oil and Gas Fields (Volume 1) [M]. Beijin...

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Problems solved by technology

[0016] The present invention provides a shear-resistant dendritic polymer oil displacement agent and its synthesis method, aiming to solve the problems existing in the application of common polymers provided by the prior art in medium and low permeability reservoirs. At low shear rates, The polymer has a high apparent viscosity and cannot be well injected into medium and low permeability reservoirs. However, under the action of high shear, the viscosity retention rate of the polymer solution is low, and the viscosity drops rapidly, and it is an irreversible process. The actual control degree of polymer flooding is limited, it cannot penetrate deep into the reservoir well, and the long-term stability is poor, which seriously affects the application effect of polymer flooding technology

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