Research Of High-performance Injection Technology In Fuyu Oilfield Redevelopment Pilot Site

PetroChina redevelopment engineering which purpose is enhancing the recovery factor and improving the development result of old oil field directed for recovery of old oil field aiming at the contradictory and fact of water-driving old oil field that the declining benefit and the rich quantity of remaining recoverable oil are exist in meantime.In this paper, the redevelopment pilot site in Jilin oil field was selected for research. The abundant geologic, seismic, drill, logging and dynamic data was used for refounding geological system by using the theories of petrology, sedimentology and sequence stratigraphy. Research of remaining oil pattern and identifying the water channel was run through the means of production dynamic analysis , theory of reservoir engineering and double wells analysis. High-performance injection technology was generated by the research of layer recombine, re-disposition the well pattern and policy of injection, which used driving test in laboratory, simulation and pilot well group.Main creative achievements in the paper are as following:1.The marks of sub-divided stratum and logging in different levels were built. Fuyu series was divided 4 sand series and 13 layers.2. According to the character of lithology, physical property, size, sedimentary structure, sediment sequence and sands distribution, sedimentary environment of the Fuyu layers in pilot blocks were meandering land facies and delta facies. Basing on these, there have 3 types meandering river sub-facies and 6 types micro-facies.3. The five-level classification standard was built up which formed in the sand body in meandering river point bar and distributary channel , The analysis of scale elements and sands configure deeply described the relationships of sand connection and contact.4.The types of remaining oil in monosandbody were classified mudstone screen, thin bed, isolating sandbody and cut-stacking sandbody. It was known that water channel was exist in layer when then sandbody thickness>4m and water flushed thickness<35%, 5.It can be indicated that viscosity of oil can affect the sweep efficiency obviously and more oil viscosity caused less sweep efficiency. More multiple of water injection caused more sweep efficiency. But when multiple of water injection was up to a limit, the rising of sweep efficiency was not obviously following adding multiple of water injection.6. In meandering river point bar, it is better that the injection well and the production well are at different sides of the standard than in same side. It is better that injection well was up block.and production well was down block.7.The waterflood development degree was raised after improving injection amount for increasing the pressure in low pressure layer. The amount of injection water must be limited in a fitness band and controlled fitness water amount and the ratio of injection and production.