Initial study on Characteristics and Development with Horizontal Wells of Heavy Oil Reservoirs with Small Bottom Water in Offshore

QHD32-6 Oilfield belongs to heavy oil reservoirs with small bottom water.The development of the oilfield has accessed to the stage with high water cut after development for many years.Water breakthrough regularity and residual oil distribution regularity are complex due to reservoir heterogeneity and many interbeds,etc.In view the problems above,the paper presents the study on water breakthrough regularity and residual oil distribution regularity;optimization horizontal well parameters and pilot test with horizontal wells based on reservoir numerical simulation.The results of the study show that,vertically,water breakthrough is more serious in the bottom of oil-bearing formation and therefore residual oil is relatively small and water breakthrough is light in mid to upper formation and therefore the mid to upper formation is the oil-rich region;and laterally,the oil that can be recovered is only from the region adjacent to well bore,namely,no water breakthrough between wells and in mid to upper formation and therefore oil is rich in those regions.It is proved in practice that recovery percentage and recovery factor can be increased with horizontal wells for heavy oil reservoirs with small bottom water in offshore.