投球滑套分段压裂用可分解压裂球

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

研制了适用于多级投球滑套分段压裂的可分解压裂球,分析了可分解压裂球材料的分解特性及力学性能,并对可分解压裂球进行了地面承压试验及现场应用。可分解材料是1种镁合金,密度在1.8-2.0g/cm^3。实验研究表明：可分解材料在氯化钾溶液中可自行分解,分解速率随温度升高而加快,但在胍胶压裂液中分解缓慢;可分解材料抗压强度达到360MPa,变形量达到约20%时发生断裂,断口具有韧脆混合断裂特征。地面承压试验结果表明：压裂球在80℃下能够承压70MPa,保压4h效果良好,且压裂球与球座间密封性能良好。现场应用结果表明：可分解压裂球在压裂过程中性能良好,压裂完成后可自行分解,避免了因返排压裂球产生的作业风险,节省了作业成本和时间。

A disintegrating fracturing ball used for multi-stage fracturing stimulation was studied and developed, the disintegrating characteristics and mechanical properties of the disintegrating material were analyzed, and the ball was tested in both ground pressure test and field operation. The disintegrating material is an Mg-based alloy with the density of 1.8-2.0 g/cm^3. The disintegrating material can dissolve in KCl solution and the disintegration rate increases with increasing temperature, while the disintegration rate is low in the guar gum fracturing fluid; the compressive strength of the disintegrating material can reach 360 MPa, and the material breaks when the deformation reaches 20% with a mixed ductile-brittle fracture. The ground pressure test shows that the ball can hold pressure of 70 MPa and keep for 4 hours under 80 ℃ with the sealing performance between fracturing ball and ball seat meeting operation needs. Field fracturing operation shows that the disintegrating fracturing ball demonstrates high quality performance during the operation and dissolves in-situ after fracturing, eliminating the operation risk that might be caused by fracturing ball flow-back, thereby decreasing production cost and saving operation time.