| Tight clastic rock reservoirs are characterized by tight lithology,low permeability and small pore radius.Fracture measures are usesurely taken in this low permeability reservoirs development.But during fracturing,loss of fracturing fluids,insoluble materials and residue can cause great damage to reservoirs.According to the character of ltight clastic reservoirs,this paper developed a plugging agent which can dissolve and self-repairing agent based on analyzing reasons of damage caused by fracturing fluids during fracturing.Choosing materials which are slightly soluble in water to make the series of plugging agents named ZDJ by surface-treated and surface-covered methods.ZDJ could reduce the filtration loss through temporary plugging,and it can be plug removal by dissolved.The temporary plugging rates and recovery rates all exceed 90%.Multifunctional and self-repairing agent are optimized through compounding surfactant and assistant.It can repair the damage and beneficiate the reservoir through preventing the migration of clay particles,reducing the water-block damage,enhancing the flowback capability,reducing the pressure and enhancing the displacement efficiency.The surface tension could be lower than 20 mN/m and the interfacial tension is1.6×10-2 mN/m.The damage rate of permeability is lower than 10%.The contact angle is60-70°.And the displacement efficiency is improved by 8.24%.Low damage reservoir protective additives are provided to the fracture of tight clastic rock reservoirs. |
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