Using new methods of injection

Although little has been told outside of Brazil concerning the secondary recovery operations which have been brought about, the state company, Petrobras, has been actively working on this front. In the principal producing region of the nation (Bahia), there are actually being carried on approx. 20 secondary recovery projects which recover about 62% of the oil in place. In the next 9 mo., 6 others may be put in operation that may cause this percentage to rise to 82%. Two unusual secondary recovery projects are described in detail. Petrobras engineers designed these projects and made them work. The first one is a dump flood which uses the aquifer located above as the water source. The flow of fluid from this automatic injection system is controlled to 500 cu m/day, entering a total of 6 production zones. The second is a gas repressuring project in which the injected gas, coming directly from the supply well, serves 2 zones. This direct injection project has produced very good results. In the 2 mo. it has been in effect, the pressure of the reservoir has risen 10 kg/cu cm.