In order to guarantee the fast and professional solution about types of water production and mechanism of water invasion in the Rumaila complex multilayer carbonate reservoir of Ahdeb oilfield with casing channeling

high permeability zone and situation of commingled production

a fine reservoir model which can characterize the pure aquifer zone

oil-water transition zone and pure oil zone was built. On this basis

combined with analysis of water invasion velocity in each reservoir

the various simulation curves would be calibrated by the actual typical production curves to obtain the different typical water control diagnostic plots including casing channeling with bottom aquifer coning

bottom aquifer coning with later casing channeling

single casing channeling and the section of perforation located in the oil-water transition zone with later casing channeling（including different position of casing channeling: pure aquifer zone

oil-water transition zone and pure oil zone） with dimensionless time

which would be used to distinguish and analyze the reservoir water-producing type and rules. The results showed that the water control diagnostic plots could accurately obtain the water production type and rules

decrease the downhole PLT

SWFL and other tests

and provide reliable basis for the stabilizing oil and controlling water of vertical wells.