External composite perforation technology in the Bozhong oilfield

Bozhong 34-2/4 Oilfield in the southern Bohai Sea is dominated by reservoirs with medium to low porosity,and low to ultra-low permeability.When conventional perforation technology is used,perforation with jet charges generates compacted zones,which may severely impact the productivity of oil producers.In view of the property of this oilfield,the external composite perforation technology was used to conduct perforation adding and stimulation.This technology is an innovative perforation solution involving composite charges,and includes the ignition,transmission,jet charge perforation,gas fracturing,down-hole data real-time acquisition system and surface data processing system.It can achieve dynamic overpressure fracturing,through perforation scheme optimization by simulation assessment before operation,real-time pressure monitoring with downhole high-speed pressure gauge during operation,and performance inspection via 3D sonic detectors after operation.Field application in Well BZ34-2/4-B7 reveals outstanding performance in low-porosity and low-permeability formation,with daily fluid production enhanced from 2-4 m 3 to 28 m 3.The proposed technology is simple,safe and reliable,and can draw lessons for similar reservoirs.