Preparation method of tetrahydroglyoxaline inhibitor applicable to drilling fluid

Abstract

The invention discloses a preparation method of a tetrahydroglyoxaline inhibitor applicable to a drilling fluid. The preparation method comprises the following steps of a, adding 150mL of substance A,150mL of substance B and 26.8g of substance C in a beaker; b, using 8 to 12mL of water for dissolving 7.6g of substance D, and dropwise adding 1 to 2 drops of sodium hydroxide solution; c, using thesodium hydroxide solution for adjusting a pH value of a reaction mixture to 8, filtering for removing separated white solid, distilling off the substance A, the substance B and water, and obtaining apale yellow viscous liquid; d, using chloroform for extracting to obtain a product 1; e, adding 13.6g of product 1 and 7.4g of substance E in to a three-necked flask, and obtaining an orange-yellow viscous transparent liquid; f, using ethyl acetate as an eluent, and obtaining a product 2; g, adding 60mL of substance B and 5.8g of substance F into the three-necked flask, and obtaining a pale yellowviscous liquid; h, extracting with acetone, removing a solvent, using benzene for recrystallizing, and obtaining a white product. The polyamide inhibitor prepared by adopting the method has the characteristics of high temperature resistance, remarkable inhibitory effect, less influence on rheological property, and the like, and is applicable to various water-based drilling fluid systems.

Description

technical field [0001] The invention relates to the technical field of inhibitors for drilling fluids, in particular to a method for preparing imidazoline inhibitors suitable for drilling fluids. Background technique [0002] When water-sensitive formations such as mudstone and shale are drilled with water-based drilling fluids, formation minerals are prone to hydration, expansion and dispersion, resulting in problems such as wellbore instability and difficulty in controlling the rheology of drilling fluids. Therefore, the inhibition of the drilling fluid system becomes the key to drilling water-sensitive formations. At the same time, as the scope and number of shale gas wells currently being drilled continue to expand, the inhibition of the drilling fluid system has become an important factor for safe drilling on site. [0003] Commonly used water-based drilling fluid inhibitors are mainly potassium salts, ammonium salts, and amine (ammonium) polymer inhibitors. Although t...

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Problems solved by technology

[0005] However, due to the limited adsorption capacity of the conventional inhibitors represented by the above-mentioned patent documents, desorption often occurs at high temperatures, resulting in the loss of inhibition at high temperatures.

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