Nitrogen foam in-layer plugging for cold heavy oil production

Water-cut usually increases rapidly in conventional heavy oil reservoirs with bottom water because of the big difference in oil/water viscosity ratio, and in-layer water plugging technology is still in a stage of trial and error both at home and abroad. This paper addresses the pilot and field tests of in-layer water plugging with nitrogen foam, including the stability and resistance factor of foam agent, and optimization of gas, liquid and foam agent proportion. The results of both successful and failed tests are analyzed. The features of this technology and the rule of well selection are concluded to guide the popularization of in-layer plugging by nitrogen foam.