Analysis of Sedimentary Facies of the Nantun Formation in the Huhehu Depression

Abstract

The Huhehu Depression has a relatively low level of research at present. In order to clarify the sedimentary type and evolution pattern of the Nantun Formation, comprehensive utilization of core samples, logging data, paleontology and other data, combined with the structural evolution characteristics of the basin, and by adopting paleontology, sedimentology, petrology and combined with structural geology and other technical methods, the sedimentary environment, source characteristics, sedimentary microfacies and sedimentary evolution pattern of the reservoirs in this oilfield were systematically analyzed. The study shows that this oilfield develops a middle-coarse sandstone fan delta sedimentation under a near-source-dominated terrestrial swamp-bay shallow lake environment. The traction flow is the main controlling factor, and the submarine distributary channel sand body at the front is the main oil-bearing reservoir. The sedimentary pattern has the characteristics of high water level period and low water level period sedimentary evolution.