Design and analysis of low-density, high-pressure-resistant epoxy resins for advanced leakage control: Insights from experiments and simulations

Leakage control in deep oil and gas wells is challenging, often leading to increased costs. In this study, a low-density, high-pressure resistant and thermally stable epoxy resin (BEPD) was synthesized by ring opening of 2,2-bis(4-epoxypropoxyphenyl)propane cured with 1,8-diaminonaphthalene. The material was thoroughly characterized using fourier-transform infrared spectroscopy, a universal testing machine, thermogravimetric analysis, and density testing. Comprehensive experimental and simulation analyses were conducted to evaluate BEPD's dispersion stability, its impact on the rheological properties of drilling fluid, and its effectiveness as a leakage control agent. It exhibits a high compressive strength (250.12 MPa) and a thermal decomposition temperature of 337.75 °C, making it suitable for high-temperature environments. Its irregular particle shape ensures a strong bond with surrounding strata, forming a stable plugging layer. With a density of 1.09 g/cm3, BEPD disperses well in plugging slurry, reducing sedimentation. At dosages between 1% and 4%, it doesn’t significantly affect the rheology of the slurry and effectively prevents sedimentation. BEPD particles effectively plugged fractures ranging from 1 to 4 mm, withstanding pressures up to 11.5 MPa. This performance is due to its unique particle size distribution, where larger particles act as bridges and smaller particles fill gaps, forming a dense plugging layer. BEPD shows potential as a highly effective material for improving leakage control in deep well applications.