Daqing Oilfield is a water flooded oilfield, the injected water is usually the produced-water. It reduces the injection cost and performs a good environmental effect as well. The formation of tertiary infill wells are usually of a effective thickness less than 0.5m, and a permeability less than 0.050 Darcy, and the permeability in 60% of the formation is less than 0.010 Darcy, this kind of formations are vulnerable to be damaged, it requires a higher quality of injected water,. In tertiary infill wells, reinjection of produced-water does a more serious damage to the formation, the water absorbing thickness decreases from 76.4% of the secondary infill wells to that of 59.3% of tertiary infill wells, this result in a serious adverse waterflood development.

Through a considerable research and analyses of the injection operation , this paper suggests a finely treatment of produced-water by decreasing the suspended particle to less than 7-8mg/l, and increasing the water absorbing thickness of tertiary infill wells to 81.2%, this performs a better water absorbance. This makes the water absorbing thickness reach 66% in those formations with a permeability less than 0.010 Darcy, and the producing thickness in those formations with a permeability less than 0.010 Darcy reach to 61% in oil well, this eases the damage degree of produced-water to low permeable formations, thus performs a good waterflood effect in low permeable formations.

You can access this article if you purchase or spend a download.