Barriers/baffles in reservoirs have been considered as one of the control factors of reservoir heterogeneity.A study on barriers/baffles may provide a sound foundation for a fine characterization of reservoirs and a more accurate prediction of remaining oil distribution.By combining core observation and dynamic production data as well as logging data of 1 735 wells in the Shuyi Block in western Liaohe depression

we drew cross plots of five parameter (i.e.interval transit time

lateral resistivity

induction conductivity

porosity and permeability) in accordance with core calibrated logging curves

and analysis result of electrical and physical property tests.We classified the barriers/baffles into two types (shaly barriers/baffles and physical barriers/baffles) and established a standard and a template for their quantitatively identification.The barriers/baffles developed in the study area were mainly controlled by factors including sedimentation of flooding stage

weakening local hydrodynamics

multi-stage fluvial erosion cuttings

progradation and riverbed lag deposition.The shally barriers/baffles were mainly distributed in shallow lakes and interdistributary bays

while the physical barriers/baffles were mostly located in bifurcations of underwater channels and local areas of interdistributary bays.Barriers/baffles were scarce and isolated in the stacked channels near provenance.However

they were more frequent and thicker away from provenance.Their vertical distribution was closely related with the base level cycles and their number and thickness got larger from bottom up in the ascending semi-cycles of the middle-long term base level cycles.We also proposed that the lithology

physical properties

thickness and distribution of barriers/baffles had certain effects upon the performance of SAGD (steam-assisted gravity drainage) in heavy oil discovery of Liaohe Oilfield.