Abstract：The application of particle size distribution theory plays a key role in improving the density, early strength development and long-term stability of cement paste. At the same time, the development of low-cost systems has important strategic significance for low-cost oil and gas extraction. Based on this, this article used fractal grading theory as a guide to develop a 1.50 g/cm3 composite low-density cement system based on five types of cementitious materials as substrates, and compared its performance with conventional hollow glass microsphere low-density cement systems. The results showed that the compressive strength of the multicomponent composite system cement stone cured at 60 ℃ for 1 d, 7 d, and 28 d increased by 47.74%, 19.18%, and 9.32% respectively compared with the conventional system, while its permeability decreased by 19.44%, 23.42%, and 24.91%. At 90 ℃, the 1 d, 7 d, and 28 d compressive strength increased by 0.9%, 53.58%, and 104.23% respectively, while the permeability decreased by 23.23%, 20.08%, and 37.17%. At the same time, the early instantaneous heat release rate of the system slurry was relatively high and significantly accelerated, the hydration induction period of the slurry was shortened, the heat release peak of the accelerated reaction was advanced, and the early accumulated hydration heat release was significantly increased. Under the premise of ensuring excellent engineering performance, the cost of this system is significantly reduced compared with conventional systems, and the slurry production rate is high, which can further reduce cementing costs and has good application prospects.
2025, Vol. 0 
