Polymer Injection for Water Production Control through Permeability Alteration in Fractured Reservoirs

Water production is one of the major technical, environmental, and economical problems associated with oil and gas production. Water production can limit the productive life of the oil and gas wells and can cause several problems including corrosion of tubular, fines migration, and hydrostatic loading. Produced water represents the largest waste stream associated with oil and gas production. Therefore, it is of importance to alleviate the effects of water production. Conventionally, water production can be avoided by adopting new drilling practices such as drilling horizontal, deviated or infill wells. Different well completion designs also offers a mean to manage water production through selectively perforate dry zones, placing a liner or installing multiphase down hole flow separation equipment. Moreover, chemical treatment arises as one of the promising watershutoff techniques through polymer flooding. The proposed chemical technique examines two types of treatment, polymer/gel flooding, and cement squeeze. Water treatment process was carried out through permeability alteration principle. The permeability modification technique was tested using cores that simulate Berea sandstone reservoir that is characterized by presences of channels. The results show that permeability reduction from 4500 md to approximately 15 md using polymer/gel and cement was successfully achieved. It was also concluded that polymer gel allows practical field applications for it its ease of preparation, storage, transport, pumping, cleaning after treatment, and 2 need for normal injection wellhead pressure. The study also shows the applicability of the technique in heterogeneous reservoirs dominated by channels and fractures.