Biologically modified fracturing propping agent, preparation method therefor and application thereof

Abstract

The present invention provides a biologically modified fracturing propping agent, a preparation method therefor and an application thereof, and belongs to the technical field of oil and gas stimulation. In the present invention, sodium alginate-calcium gel serves as a shell. By virtue of the hydrophilicity of the sodium alginate-calcium gel, a propping agent is carried by a fracturing fluid into distant formation fractures. During a well shut-in process, high temperatures and an in-situ stress cause the sodium alginate-calcium gel shell to rupture, exposing an internal slurry. The propping agent in the slurry is capable of adhering to a fracture wall, thereby reducing or slowing down the migration of the propping agent during the flowback of the fracturing fluid. In addition, the sodium alginate aqueous solution coating a surface of the propping agent is capable of buffering the in-situ stress and preventing the rupture of the propping agent.