Study On Reservoir Damage Factors And Control Measures In

Denglouku formation of Fulongquan gas field is a typically low permeability sandstone reservoir. In recent years, hydraulic fracture is used in exploiting this reservoir, but appearing to be unable to continue producing and be difficult to flowback the treatment fluid.Based on the problem of the Denglouku reservoir in production process, through researching field data and doing X-ray diffraction and scanning electron microscope experiments, we get a conclution that Denglouku reservoir exist some characteristics, like pressure coefficient low, clay content high, dense core cementation. Through laboratory experimenting, we get the sensitivity characteristics of the target reservoir, which is the strong side water sensitivity, the medium weak velocity sensitivity, the weak alkali sensitivity, the medium weak acid sensitivity and critical minerals degree6000～25000mg/L. Besides, we get the work fluid type of damage is solid plugging and water blocking through performance analyzing and experiment studying on drilling fluid, fracturing fluid and killing control fluid. Becaurse of the field core restrictions, we use BP neural network, water lock index and indoor experiment to analyse the target reservoir’s extent of water lock. The results show that Denglouku reservoir has strong side water lock damage.Based on the analysis of the target reservoir damage, we decide to use the composite plugging to relieve the damage reservoir. Through experiment studying, we prefer to a retarded acid formulation and a water lock solution formulations that has acid-resisting, salt resisting, temperature resisting and anti-dilution.According to analyzing the target reservoir’s heterogeneity, layer span and cementing quality, we prefer to use foam slug diversion techniques to achieve uniform acid distribution, which not only can improve the effect of acid, but also can improve the effect of relieving water lock. Through the field test, we achieved a good result.