Low-Density High-Strength Degradable Temporary Plugging Agent

The patent uses composite materials by combining polylactic acid (60-85%), starch (5-20%), and polycaprolactone (5-10%) to create a temporary plugging agent that achieves high strength while maintaining low density. The composite structure allows the material to exhibit both structural integrity and lightweight properties simultaneously.

The patent changes the physical and chemical parameters of the plugging agent by controlling particle size distribution (1-4mm), density (1.1-1.3g/cm³), and bearing strength (>52MPa) to achieve optimal performance. These parameter adjustments resolve the contradiction between strength and density.

The patent applies dynamics by designing a temporary plugging agent that changes its properties over time. The agent provides strong plugging initially, then degrades naturally through biodegradation of polylactic acid and starch components, allowing the reservoir to restore permeability after the plugging function is no longer needed.

The patent implements discarding and recovering by using biodegradable materials that naturally decompose after serving their plugging purpose. The degradation products are environmentally friendly and do not harm the reservoir, allowing permeability recovery while maintaining plugging effectiveness during the required period.

The patent uses composite materials with different degradation rates - polylactic acid degrades faster than polycaprolactone, creating a staged degradation process. This allows the material to maintain high strength initially, then progressively degrade within 168 hours, balancing bridge plugging strength with timely degradation.

The patent ensures continuous useful action by maintaining plugging strength throughout the required period, then transitioning smoothly to degradation. The composite structure provides sustained plugging capability followed by controlled breakdown, avoiding sudden loss of function.