Problems and Countermeasures for Es_2lower Reservoir Development in the Middle Block of Shangsan Region

The reservoirs in the lower member of Es_2 in Shangsan Region of Shanghe Oilfield are reservoirs with low pore and low permeability, where siltstones and fine sands are dominated in its lithology, sandstones and mudstones are thin and interbedding. The difference between each sandbody in small intralayer heterogeneity is strong. For many years of waterflooding, the problems on injector-producer spacing, casing failure in oil-water wells and the quality of injection water have become more and more serious in the studied area . Based on the present status of oilfield development , aiming at the existed problems, it is proposed that all injectors and producers are repaired and opened, the quality of injection water is improved, the mode of pulse type cyclic water injection is used in the lower member of Es_2 in the studied area.