The Laboratory Experimental Studies On Fracturing Flowback Fluid Recycling And Reuse

Fracturing technology is one of the main measures to improve the low-permeability oil and gas production,the fracturing fluid plays an important part in the field operation.Fracturing flowback fluid is very complex,including both a vast variety of fracturing fluid chemical additives and various substances from the formation.So fracturing flowback fluid is a pollution source not to be ignored in the oil and gas field.Correlating the treatment technology with fracturing fluid preparation closely,following the rules that retaining the useful while removing the harmful,this paper presents a reusing technology of fracturing flowback fluid which is recycling the fracturing flowback fluid as a new fracturing fluid to continue to use after the advanced treatment.Thus,the proposed technology is an effective method to solve the problem of fracturing flowback fluid.On the basis of the research at home and abroad,this paper has analyzed the water quality of fracturing flowback fluid in Sulige gas field,studied the factors influencing the fracturing flowback fluid reusing,found the key influencing factors,came up with a thorough chemical processing method,which was different from the conventional mixing treatment,to make sure the treated fracturing flowback fluid be reused successfully.At the same time,it has optimized the reusing fracturing flowback fluid formula and gotten a fracturing flowback fluid recycling system that met the oil environmental requirements.These Experiments show that the Sulige fracturing flowback water quality is very complex,the key influencing factors are residual gel breaker and salinity.According to the principles of chemical reactions,the quantitative thorough chemical treating formula is 0.1% bactericidal agent+0.17%reducing agent+0.15%polyhydric alcohols chelating agent+1.06% citric acid.The performance evaluation results show that the optimized fracturing flowback fluid recycling and reuse system has good performance of shearing resistance and salt tolerance.It also possesses the advantages of perfect gel-breaking capacity,low filter loss and little residue,realizing the reuse of fracturing fluid.The proposed technology is not only of great theoretical significance and reference value for the subsequent similar research on different flowback fluid comprehensive recycling,such as polymer flooding flowback fluid,weak gel and profile control flowback fluid,variouschemical flooding flowback fluid,but also improvement and supplement for the wastewater treatment methods in oil and gas field.