Practices of the Integrated Management System for Injection Water in Brown Field –Case Study

Abstract As the exploration degree and strength are continuously increased, both average water cut and natural decline rate have the tendency for increase. Hence various problems and contradictions are exposed, it's increasingly difficult to offset the influence of production decline and water cut increase on petroleum production, which severely impacts reservoir development efficiency and economic benefit. Prominent contradictions are as follows. 1) After an oilfield enters into a high water cut stage, the conflict between injection and production is very serious, such as unequal water-flooding producing reserves, high injection pressure of some water-injecting wells, low productivity of partial oil wells because of blocking created by mechanical impurities, and poor layering water-injection technique. 2) Affected by reservoir heterogeneity and water injection, Injection profile is non-uniform in longitudinal direction, water-flooding hierarchy and degree of reserve recovery of high permeability layer is relatively high as a result. The water flooding development effect of high water cut oil field is in urgent need of improvement. 3) Influenced by reservoir's poor connectivity and injection water quality, the injection pressure is high for some injection wells, resulting to a decline of injected water volume, which couldn't meet the demand of injection allocation. To solve the above problems, it is necessary to build an integrated management system for injection, which could both cover the underground and above-ground. In the meantime, technical efficiencies should also be improved. Injection-production network is further perfected, which aids to solve the problem of lack of water injection well spots and unbalance of injection and production; Based on hydrodynamic principle, kinds of injection allocation regimes are implemented; Injection of under-injected wells is enhanced, which increases the water-drive swept volume; Tests of layering distributional injection and profile control are also conducted using various methods; Finally, quality analysis & investigation and compatibility research of injected water are completed, reasonable treatment is done according to the compatibility, which improve the quality of injected water.