煤岩气压裂高效复合破胶剂的制备与研究OA

Aiming at the current horizontal fracturing of coal rock gas wells under low-temperature conditions,the use of ammonium persulfate gel-breaking agent has poor gel-breaking effect,and it is difficult to return to the drainage,which leads to serious damage to the reservoir and other problems.In this paper,by studying the degradation mechanism of bio-enzyme breaker on polymer fracturing fluid,we form AT-1 bio-enzyme+oxidized Q-1 composite breaker system by compounding oxidized breaker.The apparent viscosity change,molecular weight and residue content of the breaking fluid were compared between the new breaking agent and the traditional persulfate breaking agent on the breaking performance of emulsion-type thickening agent fracturing fluid to investigate its breaking performance.The experimental results show that the composite breaker system can break the rubber within 4 h,and the molecular weight of the rubber breaking fluid added into the composite breaker system is as low as 1 170 g/mol by GPC method,while that of the ammonium persulfate breaker is as high as 25 590 g/mol,which indicates that new type of breakers can make the fracking fluid degraded more thoroughly.At the same time,the residue content of the fracturing fluid added to the composite breaker system can be as low as 120 mg/L measured by centrifugal method,which is less harmful to the reservoir.