Structural failure mechanism and strengthening method of fracture plugging zone for lost circulation control in deep naturally fractured reservoirs

XU Chengyuan,YAN Xiaopeng,KANG Yili,YOU Lijun,ZHANG Jingyi

Table 5 Evaluation indexes of key performance parameters of LCMs.

Grade friction coefficient Fiber aspect ratio Dissolubility rate/% D90 degradation rate at 25 MPa (evaluation of compressive strength and temperature resistance of strength)/% Degradation rate of D90 after high temperature aging (evaluation of temperature resistance of particle size)/% Low <0.5 <30 <20 >30 >30 Medium to low 0.5-0.8 30-100 20-40 20-30 20-30 Medium 0.8-1.1 100-200 40-60 10-20 10-20 Medium to high 1.1-1.4 200-500 60-80 5-10 5-10 High >1.4 >500 >80 <5 <5