Conventional proppants exhibit limited sand-carrying capacity and incomplete gel breaking below 60 °C, resulting in inadequate fracture support and reduced stimulated reservoir volume. In this study, a self-suspending, high-salinity-resistant block copolymer was synthesized by precisely controlling the copolymer composition and topology. Based on this, a novel self-suspending proppant fracturing fluid system was developed. Its sand-carrying capacity, gel-breaking behavior, friction reduction, salt resistance, and transport performance were systematically evaluated and compared with those of emulsion polymer-based fracturing fluids. The self-suspending proppant achieved complete dispersion within 45 s and maintained suspension stability for over 25 h. It supported sand loadings up to 60%, and a small amount of proppant could carry more than ten times its weight in quartz sand. The friction reduction rate exceeded 71%, averaging 2.32% higher than that of emulsion polymer systems. The self-suspending fluid demonstrated minimal proppant settling during transport, resulting in improved placement and fracture conductivity. In contrast, emulsion polymer-based systems suffered from poor dispersion, emulsion formation, and reduced viscosity and transport distance. Field trials in the Linxing coalbed methane reservoir showed that a mixture of 10% self-suspending proppant with 26% conventional quartz sand enabled stable injection and doubled gas production compared to wells treated with emulsion polymer-based fluids. These results demonstrate the feasibility and efficiency of self-suspending proppant-based fracturing fluids for use in coalbed and shale reservoirs.

This study proposes a variable pitch helical baffle plate orifice plate-type heater model to enhance heat transfer performance. Numerical simulations were conducted using Fluent to analyze the heat transfer and flow characteristics of the heater, with a focus on determining the effects of varying pitch on heat transfer efficiency. This research examines the heat transfer coefficient h, average wall temperature T, and temperature difference ΔT under different decreasing pitch intervals Δx. The results indicate that the heat transfer coefficient h decreases continuously with the heat transfer process, regardless of whether the pitch is adjusted. Furthermore, a larger decreasing pitch interval Δx leads to a slower reduction in the heat transfer coefficient. The average temperature T of the heating plates surface and the temperature difference ΔT both decrease with increasing decreasing pitch interval Δx. Specifically, when Δx = 20 mm, the average wall temperature is 2.36% lower, and the temperature difference reduces by 9.13%–10.42% compared to the Δx = 0 mm. For the best overall performance, when Δx = 5 mm, the heater's evaluation index h/ΔP1/3 achieves optimal values, with the temperature difference ΔT decreasing by 2.94%–4.02% compared to Δx = 0 mm. This configuration offers the most effective heat transfer and temperature regulation.