Invasion Simulation Experiments Study On The Edge And Bottom Water Reservoir

Edge and bottom water reservoir is widely spreaded in the oil fields at home and abroad. It’s necessity to deepen the research on edge and bottom water invasion laws and control measures.Self-desinged experimental system was used to carry on experiments on water invasion sensitivity analysis, different tilt angles and different rhythms reservoirs water invasion. Stratified saturation analysis experiments were conducted on the edge and bottom water reservoirs after its recovery, then the remaining oil distribution laws in edge and bottom water reservoirs were gotted. Experiments show that: the impact of oil viscosity on water breakthrough time is the laregest, while the impact of permeability on recovery is the largest; the greater edge water energy, the water invasion rate is; with the increase of formation dip, water breakthrough time increases, and no water recovery and ultimate recovery increases; water free production period of reverse rhythm reservoir is greater than that of positive rhythm reservoir; remaining oil saturation of positive rhythm reservoir at upper part is higher, the lower part is lower, while the reverse rhythm is reverse; bottom water coning easily leads to higher remaining oil saturation near the bottom of the well.The unique edge and bottom water invasion visualization experimental system has been designed to carry out the dimensional visualization experiments of edge and bottom water reservoirs, then some laws can be gotted, such as edge and bottom water reservoir invasion laws, oil well production performance laws and remaining oil distribution laws. Experiments show that: frontline wells will be early watered-out, and second-tier wells become the main oil-producing during the development of edge and bottom reservoir; edge extract will lower the stage water production ratio of the corresponding well momently, then the well will soon resume high water-cut water after the extract; the effect of the high water-cut wells shut-in in the short-term was obvious; stage water production rate increases with the increasing edge water energy; the recovery of frontline wells is low for its premature flooding, so the second-tier wells make a largest contribution that accout for 89.60% of the total recovery; a large of area around the frontline wells was flooded during the late period of production, but the flooding area of second-tier wells with high water-cut is confined to the vicinity of the bottom hole;Besides, nitrogen foam flooding experiment was also launched to control water and bottom water, which achieved good results. The utilization degree of the top reservoir was improved greatly due to the gas floating effects of nigrogen foam.