Preparation and application of a bio-enzyme gel breaker in Sichuan and Chongqing oil and gas field

A new type of bio-enzyme breaking fracturing fluid was prepared, which is fit for Sichuan and Chongqing gas field, through a series of laboratory evaluation experiments. The bio-enzyme gel breaker is specific for the hydroxypropyl guanidine gum thickener, and it has good compatibility with other additives of fracturing fluid. Compared with conventional gel breaker, it has the features such as more thoroughly gel breaking, low viscosity of backflows, low residue content, low formation damage. By using it in three gas wells in Hechuan gas field, the application results showed that this new type of bio-enzyme breaking fracturing fluid system can meet the requirements of fracturing operation, in which the residues of backflows is lower than conventional breaker system, and the production of the two wells is better.