Abstract: 

Fault－block reservoir is featured by complex fault system，multiple patterns，high dip angle and other aspects，which leads to low energy，small scale and high enrichment of remaining oil in its high－part． The remaining oil in the high－part can be effectively recovered by the radial drilling technology with low cost，simple process and high efficiency． The radial drilling parameters for the remaining oil in the high－part of different fault－block reservoirs are researched by using numerical simulation． Ｒesearch indicates that the number of longitudinal branches increases with the increase of reservoir thickness． The longitudinal location is dependent on reservoir thickness，reservoir type，injection－production conditions and other factors and it is generally appropriate to conduct radial drilling in the middle－upper part of reservoir． The optimum planar radial drilling pattern for the fault－block reservoir with a included angle of 90°is 1－branch ( middle) and it is 3－branch ( 60° included angle) for the strip fault－block reservoir． This research could provide certain guidance for the radial drilling in similar reservoirs．

Key words:fault－block reservoir; remaining oil in high－part; radial drilling; production optimization