The water absorption of Hua 11-1x in Fushan Oilfield is uneven in the longitudinal direction, and there is an ineffective water circulation in the main water absorption layer. At the same time, the streamlines on the plane are not balanced. The production of each oil well in this well group decreases obviously, the water content is high and there is still an upward trend. The project department decided to take deep profile control measures to improve the heterogeneity in the interlayer, inhibit the water channeling of the high permeability strip, expand the swept volume of the injected water, and achieve the purpose of reducing water and increasing oil.
This measure adopts the combination of ' main slug of gel dispersion + gel adjustment slug '. The main slug of gel dispersion is used to carry out deep profile control and flooding of the dominant channel. According to the injection pressure, the gel adjustment slug is supplemented to plug the large channel or fracture of water channeling, so as to expand the swept volume of injected water and improve the recovery rate of water flooding.
Since February 26, the profile control agent has been injected, and the cumulative injection is 3170m3. Before the measures, the well is generally injected with water, the daily water injection volume is 30m3, the oil pressure is 14.3MPa, the casing pressure is 13.79MPa, the oil pressure in the injection process is gradually increased from 14.3MPa to 18.3MPa, and the oil pressure in the subsequent water flooding is 16.5MPa ~ 17MPa, indicating that the measures have achieved the steering effect of profile control fluid flow, and there is no near-well pollution.
After the measures, the daily oil production increased significantly, the daily gas production increased slightly, and the water content decreased from 78% to about 70%. When the daily liquid production was maintained at the level before the measures, the daily oil production increased by 18% ~ 42%, and the oil production increased significantly. By the end of August, the absolute oil increase ( not considering decline ) of the well group was 106t.
In this construction, the gel dispersion profile control agent was prepared on site, and the particle size of the profile control agent was adjusted many times according to the pressure change, which ensured the smooth injection. The success of the well also shows that the gel dispersion still maintains good profile control under poor water quality conditions in Fushan Oilfield.
