Preparation and Performance Characterization of Novel Shale Inhibitors

ABSTRACT In order to reduce the huge economic loss caused by clay hydration and swelling during drilling, it is very important to select shale inhibitors reasonably and efficiently. In recent years, ionic liquids have been active in various industries as a new material, among which 1‐vinyl‐3‐ethylimidazole bromide salt has high temperature tolerance and certain inhibition ability. Therefore, in this paper, 1‐vinyl‐3‐ethylimidazole bromide salt was used as a water‐based drilling fluid inhibitor monomer, and the ionic polymer inhibitor (PIAA) were prepared by solution polymerization. The optimal synthesis conditions were determined by designing orthogonal experiments, and the properties of the materials were tested and evaluated. The experimental results show that PIAA is able to withstand temperatures up to 270°C. Compared with deionized water, the size of the mud ball after soaking in PIAA solution is smaller, and the linear expansion rate of bentonite in PIAA solution for 24 h is 29%. The shale recovery rate at 160°C was 86.5%, which was higher than that of deionized water (36.6%). When the base slurry is added, the zeta potential changes from negative to positive. XRD tests show that PIAA effectively compresses the bentonite bi‐layer. After the addition of PIAA to the base pulp, the particle size of bentonite particles increased and the distribution was more concentrated. It also has good performance in the contact angle test and scanning electron microscope test, and at the same time will not damage the rheological properties of the base pulp and has a certain performance of reducing filtration loss.