Silicon-containing zwitterionic coating inhibitor and preparation method thereof

Abstract

The invention relates to a silicon-containing zwitterionic coating inhibitor for water-based drilling fluid and a preparation method thereof. The coating inhibitor is formed by copolymerizing neutral monomers, anionic monomers, cationic monomers and silicon monomers. The advantage of the present invention is that, through the design of the molecular structure, the faster charge adsorption and stronger chemical reaction coupling are combined to provide a coating inhibitor with fast adsorption speed and high adsorption strength, and the coating The inhibitor is prepared by reverse-phase suspension polymerization, the post-treatment of the preparation process is relatively simple, and the formed bead-like particles are easy to disperse and dissolve in the water phase, which is beneficial to on-site application.

Description

technical field [0001] The invention relates to a zwitterionic coating inhibitor, in particular to a silicon-containing zwitterionic coating inhibitor for water-based drilling fluid and a preparation method thereof. Background technique [0002] With the continuous development of oil exploration and development in deep and difficult-to-exploration areas, the number of difficult wells such as deep wells, ultra-deep wells, large-angle wells, horizontal wells, and directional wells is increasing. Card seriousness and other issues must be faced and resolved. In order to stabilize the borehole wall and prevent collapse, higher performance requirements are put forward for various new drilling additives such as inhibitors. At the same time, while solving technical problems, due to the reduction of oil prices, more and more attention is paid to development costs , at the same time of high performance, how to reduce or not significantly increase the cost must also be considered. Co...

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Problems solved by technology

[0003] Chinese patent CN103484085B discloses a fast-dissolving strong coating inhibitor and its preparation method. It is synthesized by emulsion polymerization with non-ionic monomers such as acrylamide and cationic monomers such as dimethyl diallyl ammonium chloride. The dosage of cationic monomers is even as high as 50% of the total amount of monomers. This product has strong inhibitory performance, no complicated post-treatment process after synthesis, and fast dissolution speed. However, the effective substance content of this type of emulsion-like coating inhibitor Only about 30%, the addition amount is large and a large amount of oil phase is used, and the cost is relatively high. In addition, when the concentration of cationic monomer is too high, it is easy to cause flocculation of viscosifying clay in drilling fluid or bridging in drilling fluid The formation of a network structure increases the viscosity of the drilling fluid system, making it difficult to control the rheological stability of the drilling fluid

Patent CN103952126B discloses a salt-resistant coating agent for drilling fluid and its preparation method, which is formed by copolymerization of acrylamide, acrylic acid, dimethyl diallyl ammonium chloride and sodium silicate, wherein acrylamide, acrylic acid and Dimethyl diallyl ammonium chloride forms a copolymer, and sodium silicate is hydrolyzed into silicic acid gel, which can improve temperature resistance and coating ability, but the cationic monomer dimethyl diallyl chloride The dosage of ammonium chloride is still high, and the product is actually a complex of two gels, there is no chemical interaction between the two, and there may be separation of the two during use, making it difficult to control the performance. This product is in powder form, when it is added to the drilling fluid, it is more prone to agglomeration and other phenomena, making it difficult to dissolve