Development and Application of Single Well Integral Injection/Production Technique

The technique,referring to the challenges posed by the shortage of flooding sources,requirements of zonal recovery,converted injection and associated gas recycling for multiple-zone production,was successfully developed.Referring to the challenges posed by the shortage of flooding sources,requirements of zonal recovery,converted injection and associated gas recycling for multiple-zone production,the technique was successfully developed as well.To supply the flooding source,the water layer was drilled while the normal injection was maintained in the injection wells.Compared with the parallel dual-pipe,the water production was enhanced from 800 m3/d to 2,500 m3/d.Based on features of geological characteristics and recovery requirements,concurrent injection and production for the different layers in a single well was obtained(gas injection/oil production,water injection/oil production).The technique makes the action of a single well working as that of two so that the per-well efficiency is raised and the well-net optimization is managed in certain area.The technique has been successfully applied in 8 wells such as: SZ36-1,JZ9-3 and LD10-1at Bohai Bay,and received obvious economic benefits.The technique has become an important technical measure of EOR for old oilfields,and created a new completion mode for production completion of new oilfields.