Theoretical study of the seismic monitoring of oilfield waterflood recovery
Lun Meihou,( Department of Exploration, Daqing Petroleum Institute , Anda 151400)
In the development of high porosity and low viscosity (less than 100mPa·s) oilfield, the waterfloodrecovery is the most widely used method in the world at present to improve the recovery ratio. In the paper, accorcing to the Gassman equation and the rock density average equation, we emphatically researchon the variation law of P- and S-wave velocity and density due to the replacement of oil with differnt oilgas ratio in sandstone reservir by water in waterflood enhanced recovery. The trial computation forthree geological models are performed to analyze the variation of interface reflection coefficients caused bythe replacement of oil by water. The research results show that the variation of sandstone P-ant S-wavevelocity, density, and interface reflection coefficients caused by water replacing oil is very obvious. Forthe sandstone reservoir bearing oil with high or middle oil-gas ratio, the relative change rate of reflectioncoefficients is about 30%, aometimes more than 40% or 50%. And it is at least more than 17% for thesandstone reservoir bearing oil with low oil-gas ratio. The above researches give an important theoreticalbasis for the seismic monitoring of waterflood recovery.
【CateGory Index】： P631.4