For the low-medium vicious crude reservoir, the water flooding development is always poor because of well bore blockage from asphaltene or wax condensate and high viscosity ratio between oil and water. For this reason, water flooding assisted with cyclic steam stimulation is put forward. The production well is steam stimulated periodically during water- flooding. The water flooding can maintain the pressure of the reservoir and displace the low-medium vicious oil to the production well. At the same time steam stimulation can remove the blockage around the production well, reduce the oil viscosity near the well bore and recover the oil not swept by the water. In this way the production rate can be improved a lot compared with that by only water-flooding. Through reservoir heat capacity analysis and numerical simulation, it is found that water saturation in the reservoir influence the reservoir heat capacity and temperature a little. It means that steam stimulation's thermal efficiency is affected a little by the water flooding. Numerical simulation study and field application prove that the well bore clean up effect of the steam stimulation is the main factor to improve the water flooding development. Water flooding assisted with steam stimulation is more suitable for conditions that well bore blockage is serious, oil viscosity is relatively high and reservoir rhythm is positive. It is best to use the steam stimulation in the well bore blockage wells as soon as possible. Simulation study and field application indicate that in general the oil production rate can be increased 2 ～5 times through water flooding assisted with steam stimulation than that by only water flooding.
展开▼
