Research on the Division of Small Layers of the Yan’an Group in the Western District of Mahuang Mountain

Abstract

To supplement, adjust and improve the division plan of crude oil strata in the west of Mahuangshan Mountain. Combining well logging, core, and drilling analysis and testing data, Petrel software was utilized to classify and compare the 10 layers of the Yan’an Formation. Draw 6 “net-like” skeleton profiles for Ningdong No. 2 and No. 3 wells, involving 31 wells. On the basis of the large-layer strata division, Yan 8 and Yan 9 sections are divided and compared; five “net-like” skeleton profiles were drawn in the 5 well, involving 16 wells. On the basis of the large-layer division, the small-layer division and comparison were performed by Yan 8 and Yan 9. The results show that the Yan 8 oil layer is divided into two stratigraphic units, and Yan 8 and Yan 82, and the Yan 9 oil layer is divided into two stratigraphic units, Yan 91 and Yan 92; the Yan 2 layer in the 2 and 3 well blocks of Ningdong is in the marker layer. The top of the coal seam, Yan 8 layers in the Ningdong 5 well area is on the top of the auxiliary marker seam. The fine division of small layers into tiny layers of sedimentary microfacies, reservoir heterogeneity, development dynamic analysis, remaining oil distribution and other studies provide indispensable data.