Study of Dissolvable Fracturing Ball Prepared by Magnesium Alloy
Unconventional oil and gas reservoirs are usually trapped in rocks and are very difficult to be extracted.The fracturing ball,which is utilized to seal the ball seat,is the key component in multistage fracturing systems.When fluid pressure exceeds the rock tensile strength,microcracks form and result in the release of oil and gas reservoirs.To avoid excessive deformation,the ball material must have sufficient tensile strength and low density.Here,we report that AZ91D magnesium alloy with nickel-coated diatomite could improve compressive strength,compression ratio and hardness by forming Al3Ni and Mg2Si phases.It is noteworthy that the corrosion resistance of the alloy can be cotrolled easily.Namely,the balls can be dissoved,need not to be pumped out when the fracturing process is completed.The experiment results showed that the compressive strength,compression ratio and hardness of the AZ91D alloy with the addition of 2 wt.%nickel-coated diatomite reached to 79.2 HBS,15.2%and 435 MPa after the solution aging at 415℃.And the corrosion rate of the alloy added 3 wt.%nickel-coated diatomite was 18.026 mg/cm–2·h–1 in 0.5%NaCl solution at 50℃ for 12 h.The results indicate the AZ91D magnesium alloy with nickel-coated diatomite is suitable for the manufacture of dissolvable fracturing ball due to its good strength and suitable corrosion resistance.The study on the novel magnesium alloy could provide insights into the design of novel fracturing balls.
Fracturing Nickel-coated diatomite Disintegrating magnesium alloy Corrosion
Lei C.N. Hu Y. Yang B.
Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Bei State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing, Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Bei
国际会议
北京
英文
1015-1021
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）