Channel sandstone reservoirs are generally poor in continuity and small in area.These features

in combination with the scarcity of basic data

make reservoir simulation difficult to work effectively.According to the dynamic regular patterns of the reservoirs

this paper puts forward statistic relationships between the injection and production index of channel sandstone reservoirs

including double logarithmic linear relationship between cumulative liquid production and time

semi-logarithmic linear relationship between cumulative water injection and the cumulative oil production.Based on the statistic relationships

we derive the relationship of the cumulative liquid production

monthly oil production

monthly water injection

monthly injection-production ratio with production time.Furthermore we set up a series of formulas for proration and injection allocation that can reveal the increasing of cumulative liquid production

monthly water injection and monthly injection-production ratio with time

and the decreasing of monthly oil production with time during stable waterflooding stage.The formula application in Zhuang 106-54 sandstone

Laohekou oilfield

indicates that the monthly oil production decrease obviously

whereas the daily water injection and monthly injection-production ratio increase monthly

a trend in accordance with the regular pattern of water flooding sandstone reservoirs.The proration and injection allocation approach has been successfully applied in Zhuang 106-54 sandbody of Laohekou oilfield and has contributed significantly to the stabilization oil production.