High-resolution sequence stratigraphy in layer correlation: A case study from Shahejie formation in Huanghua Depression

Layer correlation is a basic work in hydrocarbon exploration and development, but is often interfered with by diachronous correlation. High-resolution sequence stratigraphy (HRSS) is a new way for layer correlation. To make the classification scheme based on base-level cycles correspond well with the fourth- grade traditional reservoir division scheme in practice, we matched oil group correlations and sand group correlations with the flooding surfaces of mid-term and short-term base-level cycles, respectively. We also provide a model and example of layer correlation in an isochronous stratigraphic framework, and built a layer- correlation model foundation based on the stacking patterns identified from short-term base-level cycles in logging curves. The applicability of this method was tested in the middle oil group of 2nd member of Shahejie formation of Chengbei low-fault terrace. This member consists of 3 mid-term base-level cycles according to HRSS, and its middle oil group is made up of 5 short-term base-level cycles in the braided river delta deposition system.