Development And Application Of Anti-collapse And Leak-proof Drilling Fluid In Honggang

In Honggang of Jilin oilfield,the development of dense oil well area need to solve is the key problem of black mud shale borehole wall instability,horizontal well serious collapse and leakage phenomenon existing in the construction process,construction safety and progress of the influence of horizontal Wells,drilling cost is high.This article obtains from the physical and chemical properties and mechanical properties of the shale,and it is concluded that the region was black paragraph belongs to the hard brittle shale formation,including Iraq/slip layer and illite content is higher,cracks and microcracks is rich,easy to cleavage fragmentation in clean water.Is obtained by analyzing the main cause of borehole wall instability is introduced into micro cracks in drilling fluid column pressure,borehole wall caused by stress changes,the layer/get uneven expansion of formation of cleavage and the drilling along the direction of the bedding.Combined with GMI software,a safe density window is recommended in this area.Strengthening drilling fluid plugging and inhibitory is the key to solve black period of mud shale borehole wall instability,based on the formula to join the plugging agent,and protecting the enhanced drilling fluid plugging and inhibitory,high temperature and high pressure filtration volume of only 1.6 m L,16 hours of linear expansion rate of 0.0495.Optimized formula red flat 10 Wells in Jilin oilfield and red 19 well applications,the flat wall spalling and collapse phenomenon,are not found in the well construction process smoothly,downhole complicated conditions was not occurred,has obtained the good effect.