Research On Protection Technology For Sensitive Reservoir During Well Workover In Langgu Sag

In the process of oilfield development,remedial work is not only an essential measure,but also an important operation during production.Remedial work is the key method to guarantee normal production and keep normal operation of oil field.However,the improper use of working fluids during the process may result in reservoir damages and production reduction.After years of exploration and development,the sensitive parts of Langgu Depression in Huabei oilfield were found to have low formation energy.The misuse of working fluids during killing operation and improper remedial technologies would result in different degrees of damage to the reservoir,what’s worse,oil well productivity would be severely restricted,the afterward drainage period would be longer and it’s really difficult to restore the original production conditions.In order to avoid or reduce the damage to reservoir,on the basis of field survey,this article was devoted to evaluate the damage degree and mechanism of reinjection water to reservoir,to optimize the scale inhibitor and antiswelling agent,to make up a scientific and standardized managing method and to form a relatively mature operation technology without hydration to protect reservoirs.This technology mainly includes drain devices,rod pump,negative pressure deoxidization process and so on,it’s really meaningful for ensuring stable production rate and improving ultimate recovery of the reservoir.