Synthesis and evaluation of a novel clean hydraulic fracturing fluid based on star-dendritic polymer

The hydraulic fracturing fluid formulation was designed using the DSPAM as thickening agent. For the purpose of evaluating the performance of the new fracturing fluid, shear resistance, thermal stability, rheology property, viscoelasticity, proppant transportation and breaking ability were tested by several experiments. The results show that the fracturing fluid has an excellent shear resistance under high temperature. The apparent viscosity remains 140 mPa s after 2hr shearing when the testing temperatures are 90 °C and 140 °C. So the fracturing fluid has an acceptable thermal stability. The static proppant sedimentation velocity is from 0.038 cm/min∼0.095 cm/min when the testing temperatures are 60 °C and 90 °C. The sedimentation velocity increases with the rising temperature when the sand proportion remains constant. In addition, the increasing of sand proportion could cut short the time of proppant settlement. The residual contents after breaking are hardly measured in various testing temperatures. A star-dendritic polymer was synthesized as a novel fracturing fluid thickening agent. The properties are acceptable to meet the requirement as the thickening agent due to the thermal resistance, shear resistance and proppant carrying ability of the fracturing fluid are quite effective in hydraulic fracturing treatment.