{'fraction_non_alphanumeric': 0.0203527815468114, 'fraction_numerical': 0.0, 'mean_word_length': 5.3076923076923075, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Evaluation of Ordovician Carbonate Source Rocks in the Dagang Oilfield, China

Ordovician carbonates in the Dagang Oilfield are of wide distribution and have large thickness. Though their organic matter abundance is relatively low, it has reached the standards for carbonate source rock, with most of them being thought to be medium source rocks. These carbonates, whose bio-inputs were mainly of blue bacteria, were deposited in a weakly reducing or weakly oxidizing environment. Their organic maturity is at mature to over-mature phases in most areas, therefore, they should possess geological and geochemical conditions for oil/gas generation and expulsion. Attention should be paid to the Ordovician carbonates in future exploration.