Abstract: As the oilfield development enters into high containing water stage，the controlling function of the interlayer on the remaining oil is more and more obvious. From the description of interlayer，combining the cases of Liangjialou oil field， according to the shape， the distribution position and its controlling function on the remaining oil， the interlayer can be classified into 11 styles， such as upper protruding style， upper concave style， upper board style， middle protruding style， middle-concave style， middle board style， lower protruding style， lower concave style， lower board style， crossing style and arc style，and its functions on the remaining oil are described〖JP2〗 respectively. The result is that the remaining oil is most rich in the interlayer of upperprotruding style， and most poor in the interlayer of middleconcave style. In order to enhance the recovery of oil， the remaining oil sealed by upper interlayer is suitable for the horizontal wells and waterblocking， and the remaining oil sealed by middle interlayer is suitable for the instability injection， and the remaining oil sealed by upper and lower interlayer is suitable for the combining of waterblocking and holepatching.

Key words: intercalation, remaining oil, distribution pattern, enhance oil recovery, Liangjialou oil field