DEPOSITIONAL SYSTEM OF THE THIRD MEMBER OF THE SHAHEJIE FORMATION IN LENGJIA OILFIELD OF THE LIAOHE BASIN

With seismic facies analysis and core data, distribution of depositional system of the 3rd Member of the Shahejie Formation in Lengjia oilfield of the Liaohe Basin, is studied. According to seismic reflection structure, it can be divided into 3 types: slope, plat form and depressed area, including 16 seismic facies. Based on fan-delta front and pro-fan delta, slump deposition, island in the center of lake, sand bank, longitudinal fan, slope progradation complex, slope fan, sublacustrine fan and barrier system are found. Longitudinal delta is developed in the north, fan-delta in the east, and slope progradation complex in the west.