Disintegrating fracturing ball used in ball injection sliding sleeve for staged fracturing

Abstract

Abstract A disintegrating fracturing ball used for multi-stage fracturing stimulation was developed, the decomposable characteristics and mechanical properties of the decomposable material were analyzed, and the ball was tested in both ground pressure test and field operation. The decomposable material is an Mg-based alloy with the density of 1.8-2.0 g/cm3. The decomposable material can be dissolved in KCl solution and the decomposing rate increases with increasing temperature, while the decomposing rate is low in the guar gum fracturing fluid; the compressive strength of the decomposable material can reach 360 MPa, and the material breaks when the deformation reaches 20% with a mixed ductile-brittle fracture. The ground pressure test showed that the ball could hold pressure of 70 MPa and keep for 4 hours under 80 °C, which meant that the sealing performance between fracturing ball and ball seat met operation needs. Field fracturing operation showed that the disintegrating fracturing ball demonstrated high quality performance during the operation and dissolves in-situ after fracturing, which eliminated the operation risk that might be caused by fracturing ball flow-back, thereby decreased production cost and saved operation time.