The study analyzed the sedimentary microfacies and oil-bearing characteristics of the Chang3 oil reservoir in the Huachi Oilfield. The researchers found that the reservoir is part of a delta front subfacies and can be divided into four sedimentary units with distinct features. These units contain various sedimentary microfacies, such as subaqueous channels and debouch bars, which together form a complex delta front sandbody. This sandbody is crucial for the formation of the oil reservoir in the Yanchang Formation of the Eerduosi Basin.