Laboratory Study Of Weak Acid And Low Damage Fracturing Fluid

At present, most of the fields have entered the stage with high moisture content. Sofracturing as an important stimulation is particularly important. When we construct on thelow-permeability reservoirs. It may cause damage to the reservoir matrix and fractureconductivity. Including the expansion of the clay migration, water sensitive, desensitization,wettability reversal and so on. In order to reduce the damage to the reservoir. We should focuson reducing the water-insoluble content of the fracturing fluid system. Enhancing thetemperature, shear resistance of fracturingfluid. The capacity of gel breaking. and improving thecompatibility between the fracturing fluid and formation fluids.Through a lot of theoretical analysis and experimental studies. The water insoluble matterof modified guar gum we composed is only4.4%. It has reduced about20%than before. It hasa better tackifier performance. The cross-linker we composed can cross-link in weakly acidicconditions. So it can avoid the damage of the fracturing fluid to the formation of desensitization.And the fracturing fluid has higher strength, stability. It has a better gel breaking performanceafter which the viscosity is1.87mPa·s. So it may reduce the residue’damage to reservoirpermeability greatly.After the synthesis experiments. We evaluated the performance of the fracturing fluidsystem. The results showed that the fracturing fluid system can meet the requirements of thefracturing operation. Under the conditions of90℃,170s-1、. Its viscosity can stay above60mPa·safter150min cutting. We get the loss coefficient is2.7through a formula. Therefore, comparedwith conventional fracturing fluid, the fracturing fluid we discussed has a low damage to the oilfield and it is more effective to protect the reservoir permeability.