A slope zone is an important region for hydrocarbon migration and accumulation

thus has relatively high exploration potential.Through integration of seismic

well logging and oilfield production data

this paper studied the oil reservoir characteristics and important exploration targets in the Fuyu oil layer in the western slope zone of the northern Xingshugang oilfield

Songliao Basin.The results show that oil reservoirs in this area are developed under the joint control of fault and lithology

and the major oil reservoir types include fault-screened

fault block

fault-nose

fault anticline

updip lithologic pinch-out

and fault-lithologic reservoirs.These oil reservoirs are characterized by 'upper oil and lower water without unified oil-water contact’.Two hydrocarbon accumulation patterns are identified in the Fuyu oil layer

namely downward migration and accumulation within the source kitchen and lateral migration and accumulation beyond the source kitchen.The former refers to that

driven by the paleo-overpressure of the Qingshankou Formation

the oil sourced from the 1

st

Member of Qingshankou Formation(K

2

qn

1

)

migrated downward along the faults connecting the K

2

qn

1

source rock and the underlying sand bodies and traps of the Fuyu oil layer

forming oil reservoirs.The latter means that the oil sourced from the K

2

qn

1

source rock in the Qijia-Gulong depression first migrated downward to the Fuyu oil layer

and then migrated laterally into the northern Xingshugang region along pathways such as sand bodies and faults connecting the Qijia-Gulong depression and the northern Xingshugang region

forming oil reservoirs.The distribution of oil reservoirs are mainly controlled by available oil sources

match of faults and sand-bodies

and antithetic normal faults.The overpressure of the Qingshankou Formation is the key to ‘downward migration’ of oil

while abundant oil sources form the material basis and match of faults and sand-bodies provides pathways for ‘downward migration’ of oil.At last

it is suggested that the hanging walls of antithetic normal faults in good match with sandbodies are important targets for oil exploration.