Fine water injection technology "moisten" 620 wells in Old Oilfield

The water flooding development in the old oilfield has entered the late stage, and fine water injection has become the key. Up to now, the "old oilfield fine water injection integrated supporting technology" has been moisten and 620 wells in the Shengli old oil area have been developed in Shengli Petroleum Engineering Technology Research Institute. The injection rate of oil field has increased from 43.2% at the beginning of the year to the present 45.1%, and the qualified rate of the layer is raised from 77.3% at the beginning of the year to 78.4% in the front of the eye. The eastern old oilfield has provided strong engineering and technical support for improving the recovery efficiency of water drive reservoirs.

In order to improve the demand for the quality of water flooding in the old oilfield, combined with the current situation and characteristics of oil reservoir development in Shengli Oilfield, water injection puts forward the project research on "integrated matching and scale application of fine water injection technology in old oil fields". The key technologies such as long effect fine injection and so on are made to integrate the standardized pipe columns of different wells in different reservoirs and to improve the efficiency of the ground water injection system, forming a series of fine water injection technology in the old old oil fields.

Since its opening in 2017, the project has been running in high quality according to the plan. At present, all the research contents have been completed, and it has entered the stage of large-scale promotion and implementation. The fine stratified water injection technology of the rhyming layer formed the process of water injection in the unejection layer and the thin interlayer fine sealing water injection technology, and developed the key injection tools such as the double medium multi cylinder expansive packer and the sealing integral regulator, which realized the minimum distance of 1 meters and the 2 meter index of the long glue tube blocking well. The fine pressure difference injection technology is used to form a series of soft anchorage and peristaltic technology suitable for different conditions of well conditions. The key injection tools such as peristaltic packer and small flow and large pressure difference throttling water distributor are developed. The starting throttle pressure difference reaches 4 MPa, the pressure difference between layers is 12 MPa, and the low permeability reservoir is difficult to enter into the high adjustment instrument for water injection pressure. The electric continuous transmission and high pressure seal blowout prevention device of the cable are developed. The seal pressure difference is 32 MPa, the continuous downlink speed of the cable reaches 5 meters per minute; the ground water injection system completes the optimization of the staircase pump combination scheme. The field test is carried out in the Dongxin oil plant Lai 89 water injection station, and the energy saving effect of the unit after optimization of the pump group is analyzed and compared. The effect of raising efficiency and reducing consumption is remarkable by 5.4%.

Up to now, the fine water injection technology in the old oilfield has used 620 test wells in the old Shengli oil area, covering a total of 36 block units, including the whole assembly, the fault block and the low permeability reservoir. It is based on the long effect control of the water well, the demonstration area of the injection and the integrated management of the old oil fields and the implementation of the fine stratified water injection technology. The upgrading provides strong technical support for the benefit development of old oilfields.