Alluvial fan is a typical continental fan accumulation formed after the outflow of the river (flood). There are two kinds of sedimentary mechanism, the traction flow and the debris flow in the fan root area，which make the sedimentary model of alluvial fan complicated. The exposed alluvial fan phenomenon is well in Zhebu countryside, Laiyang city, Shandong province, which belongs to Cretaceous Wangshi group Xingezhuang Formation. Through the detailed observation and measurement on the section, using the sedimentary principle of the outcrop, the sedimentary environment was thought being an alluvial fan, which developed chaotic accumulation of conglomerate facies (Gms), massive bedding conglomerate facies (Gmh), trough cross bedding sandstone facies (St), planer cross bedding sandstone facies (Sp), horizontal bedding sandstones (Sh), floodplain mudstone (Fl) and massive bedding mudstone (M). The trough flow facies belt, slice flow facies belt, braid flow facies belt, runoff facies belt were identified. The facies of the trough flow belt and the slice flow facies belt were the least exposed, and the upper part of the main section was mostly debris flow deposits. The facies of the runoff facies and the braided flow facies were the most exposed, showing the characteristics of the interaction between sand and mud. In view of this, based on the study of the sedimentary characteristics of different facies zones, the sedimentary model was established and the evolution characteristics of the profile were analyzed combined with the outcrop characteristics of alluvial fan in Laiyang, Shandong province.

Combining with the physical property data in the study area, logging interpretation results and field test data, the distribution function curve method and the method of oil are used to calculate the physical property lower limit and depth of the effective reservoir in the lower member of Sha 3 of Chengnan fault zone. The physical relationship between them is fitted by software. On this basis, the controlling effects of burial depth, lithology, sedimentary facies and diagenesis on the development of effective reservoirs in the study area are discussed. The results show that the effective reservoir property in the study area by the factors such as buried depth, sedimentation and diagenesis control together, effective reservoir physical property lower limit decreases with increasing of buried depth, advantage for fine breccia facies and conglomeratic sandstone, due to the deep compaction cut hole depth obviously later dissolution as the main mechanism of hole, which is the main control factors of sedimentary facies. The effective reservoir in the study area are mainly distributed in the nearshore submarine fan, sublacustrine fan and fan delta, fan delta deposition is the most favorable sedimentary facies.