Pilot Test of Deep Profile Controlling and Sweep Improvement Based on Plugging Agent Location Optimization in Offshore Oilfield

Abstract

After the reservoir enters the medium-high water-cut period, due to the heterogeneity of the reservoir, the difference of fluid mobility, and the difference in injection and production, large water flow channels are gradually formed in the formation, which result in fixed streamline in the formation, and the inefficient or ineffective water circulation. Ineffective injection water circulation severely inhibits water flooding effect. Conventional tapping measures can’t change the problem of ineffective water circulation. However, the profile control technology changes the flow direction of subsequent injected water by plugging the high permeability layer or large pores, improving the water injection profile, and increasing the formation water retention rate, so as to expand the swept volume. Therefore, profile controlling technology has always been an important method water control and oil stabilization technologies for the reservoirs with thief zones. The success or failure of profile control measures depends to a large extent on thief zones identification and its description, sensitivity analysis of plugging agent performance, scientific and reasonable profile control decision-making and optimization, in addition to selection of candidate wells, optimization of construction parameters, effect prediction and effect evaluation.