Plugging characteristics of self-degradable diverters within three-dimensional hydro-fractures: An experimental investigation

Abstract

The dominant fracture can be effectively plugged by injecting self-degradable diverters during temporary plugging fracturing. The subsequent fracturing fluids can divert into the poor fractures. The fracture complexity can be enlarged and the well production can be enhanced. This study established a new diverter temporary plugging evaluation system and carried out 23 groups of temporary plugging experiments to investigate the plugging characteristics of diverters within three-dimensional (3D) hydro-fractures. Experimental results show that (1) the formation process of a temporary plugged zone is determined by the bridging capability of the most significant particulates; (2) the tight plugged zone can undergo diverter attachment, bridging, filling, and compaction or diverter bridging, filling, and compaction; (3) diverters are most likely to plug distorted fractures, followed by inclined-flat fractures, and then axial/transverse-flat fractures due to the varying widths of hydro-fractures; (4) pure fibers can plug hydro-fractures when the fracture width is less than 1.5 mm, and the difference in the diameter of bridging particulates and the fracture width should be less than 1.5 mm when the fracture width exceeds 2.5 mm. Meanwhile, this study investigates the optimal temporary plugging agent formulations for different fracture widths based on economic factors and operational conditions, providing on-site recommendations.