Preparation And Performance Evaluation Of High Temperature Guar Based Fracturing Fluid

As an important method to stimulate hydrocarbon production,hydraulic fracturing has been widely used since the first hydrocarbon exploitation construction.With the increase of mining reservoirs temperature,the demand for the temperature resistance of fracturing fluid increased as well.The widely used high temperature fracturing fluid both at home and abroad has certain shortcomings,which also limits its application in practical production.Therefore,the development of more efficient and high temperature fracturing fluid is of great significance for the improvement of fracturing construction and hydrocarbon exploitation.This research mainly starts from the perspective of crosslinking agent,then adopts the one-pot method to prepare an organic boron-zirconium crosslinking agent BCL-165,and applies the synthetic crosslinking agent and hydroxypropyl guanidine gum base liquid to prepare a maximum temperature of up to 180?High temperature guar based fracturing fluid.The organoboron-zirconium crosslinking agent is prepared using boric acid and zirconium oxychloride as the main body,and water and glycerin as the solvent.The synthetic conditions were optimized by analyzing the concentration of synthetic raw materials,the type and concentration of organic ligands,and the reaction performance of organo-boron-zirconium cross-linking agent at different conditions.The effect of the optimization of the synthesis conditions:25%mass fraction boric acid+zirconium boron zirconium molar ratio of 3:1+hydroalcohol molar ratio of 3:1solvent+molar ratio of 5:1 organic ligand ligand LG-1 and LG-6 were reacted under the conditions of 50?and p H=8.5 for 5h.The synthetic organic boron-zirconium cross-linking agent BCL-165 was used to optimize the additives of fracturing fluid at 140?,160?and 180?,and the temperature resistance of high-temperature guar gum fracturing fluid was studied by considering different factors.The optimal formula of high-temperature resistant guar gum fracturing fluid at various temperatures was thus obtained,among which the formula of fracturing fluid at 180?was:0.6%HPG+0.5%crosslinking agent BC-165+0.25%p H regulator Na₂CO₃+0.12%temperature stabilizer TS-1+0.5%drainage aid SF-13+0.3%anti-swelling agent SK-5+0.5%bactericide BT-2,after shearing at180?,170s^-1 for 120min.The viscosity is kept at above 120 m Pa·s.The temperature resistance,shear resistance,fluid loss performance and gel breaking performance of the fracturing fluid system at three different temperature conditions were evaluated respectively.Results show that the indexes of these three systems greatly exceed the industry standards and have the great potential for practical applications.