Preparation method of polyamine inhibitor for drilling fluid

Abstract

The invention discloses a preparation method of a polyamine inhibitor for drilling fluid. The method comprises the following steps: an amine compound of low molecular weight and heterocyclic compounds are reacted in a setting condition for synthesis, and the amine compound is one of triethylene tetramine, trimethylethylamine hydroxide, N-methylethylamine, and trimethylhexamethylenediamine; the heterocyclic compound is 1,2-epoxypropane or 2,3-epoxybutane or 1,3-epoxybutane; the setting condition is as follows: alkali metal is used as a catalyst, and the reaction temperature is 80-100 DEG C; charging mol ratio between the amine compound and the heterocyclic compound is 1:2.5; the mass ratio between the amine compound and the alkali metal catalyst is 1200:1. The inhibitor has high inhibition capability for shale, and has good compatibleness to other common drilling fluid additives; the inhibitor is nontoxic and environmentally friendly.

Description

technical field [0001] The invention relates to the technical field of oil and gas drilling, in particular to an inhibitor suitable for water-based drilling fluid for shale gas horizontal wells. Background technique [0002] For shale gas water-based drilling fluids, the key to ensuring wellbore stability is to provide good inhibitory and plugging properties. With the development of current drilling fluid technology, different types of inhibitors with different characteristics have been developed. It is found that amines have a good inhibitory effect on mud shale, and have been gradually introduced into the water-based drilling fluid system as a main inhibitor. [0003] For example, the publication number is 102504065A, and the Chinese patent literature published on June 20, 2012 discloses a polyamine inhibitor for drilling fluid and a preparation method thereof. In the reactor, under normal pressure and nitrogen protection, add sulfonylating agent dropwise to the reactor t...

AI Technical Summary

Problems solved by technology

[0004] However, in the commonly used amine inhibitors represented by the above-mentioned patent documents, quaternary ammonium salts have poor compatibility with anionic treatment agents and have certain toxicity, so their use is limited; the mode of action of ammonium cations is similar to that of potassium ions, but their inhibition The time is short, the temperature resistance is poor, and it is not suitable for high pH conditions; the compatibility of amphiphilic polyamino acid inhibitors is good, and it is safe and environmentally friendly, but the inhibitory effect is not ideal in high solid phase systems. Therefore, it is necessary to introduce new functional groups. Improvement of amine inhibitors to increase their inhibitory ability