Temperature-responsive microgel and preparation method thereof

Abstract

The invention discloses a temperature-responsive self-degrading microgel and a preparation method thereof, and belongs to the technical field of temporary plugging in petroleum exploitation. The preparation method is characterized in that (1) preparing ethanol solutions of azobisisobutryamide chloride and maleic anhydride respectively, and then dropwise adding azobisisobutryamide chloride to the ethanol solution of maleic anhydride to prepare a thermally degradable crosslinking agent with an azo group, wherein the molar ratio of azobisisobutryamide chloride to maleic anhydride is 1:(2-3); (2) adding acrylamide and a thermo-sensitive crosslinking agent to a flask, and the total monomer concentration is 10 to 30%, introducing nitrogen for 30 min, adding 0.1-0.5% of an initiator to react at 30 DEG C for 4 to 8 h, pulverizing and drying to obtain the temperature-responsive thermal degradation type microgel. The microgel can be used for temporary plugging, and can be degraded into water-soluble molecular fragments at reservoir temperature after the completion of construction, and plugging removal is automatically performed. The microgel has the advantages of simple preparation, cheap and easy-to-obtain raw materials, and the like, and has broad application prospects in drilling, temporary plugging acidification, and temporary plugging fracturing.

Description

technical field [0001] The invention relates to a temperature-responsive microgel used for temporary plugging in drilling and oil production and a preparation method thereof. Background technique [0002] There are two important aspects to protect the oil-producing layer. On the one hand, it is to improve the compatibility between the drilling fluid and the formation rock and fluid, so that even if lost circulation occurs, the damage of the drilling fluid to the reservoir can be reduced to an acceptable range; On the one hand, it is the shielding temporary plugging technology, which can minimize the contact between external fluids and production layers, and is currently the most effective, convenient and economical means of increasing production. [0003] After a long period of development in domestic old oilfields, with the increase in the number of developments, the oil production of primary fracturing has been continuously reduced, and the oil wells have low production an...

AI Technical Summary

Problems solved by technology

[0004] During the acidification process, the acid liquid is more likely to enter the high-permeability layer, so that the high-permeability layer has a higher permeability, but the low-permeability layer has not been transformed

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