China University of Petroleum spread demonstration project of overall profile control with polymer microspheres in Naisikule E31 oil reservoir of Qinghai Oil Field. NaisikuleE31 oil reservoir, the depth of whose oil layer was 3200～3800m, the average permeability 45.8×10-3μm2，the reservoir temperature 126℃，the mineralization of the formation water 17.45×104mg/l, belongs to a low-permeability high-temperature high-salinity reservoir. Being a kind of continuous water-flooded single layer, the comprehensive water content of the reservoir was high. The research group of microsphere profile control of China University of Petroleum and Oil Production Plant 1 that chaired the oil field operated overall profile control with polymer microspheres in Jizhujiu Station of Naisi Zhongnan oil production plant. They looked into the conditions of the reservoir, investigated the history and the present situation of production of the 7 water wells carefully, made a fine design of the profile control process, operated carefully on the work field, and solved the three technical difficulties of deep profile control—high temperature, high salinity and low permeability. On August, 2008, 7 wells were done successively with single- pump—multi-wells online deep profile control. After the operation, the oil pressure of the water wells increased by 2MPa on average. 14 out of the 22 wells came into good effect of oil enhancement. The productivity of the block showed rising trend, the comprehensive water content dropped from 90.5% to 85.1% and the effective peak value of the increased oil was 52.5t.