GR Electrofacies analysis of Upper Paleozoic in Daniudi gas field, Ordos basin Cao Zhonghui

Gamma ray curve of the Upper Paleozoic in Daniudi gas field can be divided into 4 basic electrofacies types, including bell - shaped, funnel-shaped, box-like and finger - like electrofacies. Vertically, the basic electrofacies can occur in 6 different electrofacies combinations, including funnel - shaped + bell - shaped, bell -shaped + funnel-shaped, bell - shaped + box - like + funnel - shaped, bell- shaped + box-like, box-like + finger-like and finger - like + box - like. The basic electrofacies and their variant combinations reflect corresponding sedimentary microfacies.