Application Research of Hyperbranched Fracturing Fluid in the Tight Gas Reservoir of the West Sichuan

Fracturing fluid is one of the main factors that affect propping fracture conductivity.But common HPG fracturing fluid thickening agent has high content of water insoluble substance and gel breaking liquid residue,which brings great challenge to efficient development of middle-shallow layer in the West Sichuan.After low-damage fracturing fluid optimization,hyperbranched fracturing fluid will be applied for reducing the cost of the fracturing fluid and formation damage.Hyperbranched polymer gelled fluid is synthe sized by using quasi-one trip technique.And a new type of artificial synthetic hyperbranched fracturing fluid system is developed through functional group optimization and selection of crosslinking chemical,clay stabilizer and viscosity breaker chemical.Laboratory evaluation shows that the fracturing fluid system has a simple recipe with the characters of good crosslinking feature,good temperature resistance to shear and be ing easier for viscosity break,and low residue content and surface tension of the gel breaker.It is a clean and low-cost fracturing fluid system for its cost is about 77% of the conventional guanidine gum fracturing fluid.Application in a delineation well in some gas field of the West Sichuan shows that the friction of the fracturing fluid is ultra-low that is about 30%-50% of the conventional guanidine gum fracturing fluid.The fracturing fluid system has significant technical and economic advantages for large-scale fracturing of the horizontal wells in the tight reservoir of the West Sichuan for its quick rate of delivery and high flowback rate after fracturing.