Application of nanosphere deep profile control and displacement technology in He’nan oilfield

The nanosphere is characterized by changing injected water penetrating direction in formation porous and improving the water flood sweep efficiency. Particle sizes analysis show that nanospheres diameter are nanometer grade, and swelling times is nearly up to 100~150 after absorbing water; The simulation displacement experiment in man-made cores show that nanospheres are easy injection and single sand tube plugging rate is over 80.5%. With high and low permeability sand tube, nanospheres priority access to and block the hypertonic pipe, and then change the heterogeneity of double-barreled, finally, crude oil in hypotonic tube is started, in which the oil recovery reach over 20%. Field experiment of in-depth profile control were made on two well groups of W32 and C9 in He’nan oilfield, and the corresponding oil wells in well group showed obvious increase of oil production and the decrease of water-cut with cumulative oil increment of 1 551.4 t and water cut decrease of 12 535.6 m3. The successful application of nanosphere deep profile control and displacement technology provides technical support to improve oil recovery for the heterogeneous reservoirs.